This article’s main points are all found in different posts here on this site, and together, here and there, they all cover the ground I am re-covering here. However, this subject comes up so often I decided to try and consolidate things into one place.
I am not trying to list every single thing you need to do to build a bike (I don’t mention tightening all the bolts or putting air in the tires, for example). I’m trying to shine a light on the more common mistakes. Don’t make them and you stand a good chance of having a trouble-free bike. Some of this stuff is pricey, so maybe you’ll want to work it in bit by bit as budget permits.
Remember: a successful DIY mid drive is about both building and riding optimally. Mid drives – particularly the ones made for USA-legal and adventurous, off road DIY builders – up the ante on the required competence of both builder and rider. There is no way around this. If you want idiot-proof and simple do a hub kit. If you want the versatility that comes with a mid drive, though, you need to put in the extra time and effort. There is no way around this.
I’ll focus solely on the mechanical bits this time, and break the process down into key component areas. We’ll start with:
Pick a Frame…
To get a mid drive to work properly, you need to pick a frame that can handle it, and this is not a given. Lots of frames are a bad choice. So what are we looking for?
… That Handles The Torque
I can still remember looking down at my very first mid drive build, a 4kw Cyclone, and saw the motor flex when I hit the throttle. With that flex, the whole bottom bracket flexed with it.
Thats a bad thing. Pick a frame of very sturdy construction. You are going to have an electric motor giving one hell of a pull on a chain that is connected to your back hub. That pull can flex the entire bike frame.
Can your typical mountain bike do it? Yes. Can your road bike with Columbus tubing from the 1980’s do it? Ehhhh lets say no on that one. Whats the problem? Designed for light weight and strength keyed to relatively smooth roads and human power, the stays are too spindly. All that power can pretzel the poor, innocent chainstays and seatstays when the power of ten pro riders yank on the chain.
How do you fix that? A lighter-duty BBS02 with the amp output dialed down is one solution I have seen done successfully several times. The lower amps do not yank on the chain hard. Some effort on the builder’s part to change the settings so pedal assist is kind and gentle is also important (and also preserves an authentic cycling experience).
… That Fits The Motor
Modern downtubes on mountain bikes tend to be curved and swoopy, coming into the bottom bracket at an arc that equates to a roughly 3-o’clock position. That arc means an installed external motor like a BBSxx has no choice but to hang straight down. Kiss goodbye your ground clearance. Here’s a picture of my 2018 Guerrilla Gravity Smash:
Take a look at how the down tube is curved, and how, on the right image where the drivetrain has been removed, its clear the only way to put a BBSxx-style motor on a bike like this will result in that motor hanging straight down.
You can see, sitting on the floor in that right picture, a Cyc X1 Pro motor, which has long arms that mount the motor as far forward as possible to avoid this ‘angle of the dangle’ problem.
How did I do in terms of mounting the motor and preserving ground clearance? Well, look above at the final installation. Look how low the chainring is. Draw an imaginary horizontal line parallel to the ground from that chainring… the motor is above that line.
The higher the better, but bottom line here is the motor is above the drivetrain so we haven’t lost a lot of ground clearance on this frame by using it (with the right mounting kit a Tangent Ascent motor will fit inside the triangle, just under the shock). So, this frame that is totally unsuited to one kind of motor can be pretty well suited to another.
Here’s another example frame. This is the type of frame typically recommended for a BBSHD, BBS02 or similar motor:
The down tube of this frame is straight as an arrow and attaches to the bottom bracket at a high angle. This allows you to rotate a dangly motor like a BBSHD up as far as possible so you lose as little ground clearance as possible. How did this shake out once this bike was built?
It came out pretty good. Bearing in mind this bike used a smaller-than-usual 40T chainring, the motor is roughly at the same height above the ground as the chainring. Maybe just a bit below. This is as good of a fit as you can expect on a bike for this kind of motor.
So… the lesson here is to think through your motor choice if you already have a frame to work with. Or the reverse if you have a motor on the shelf that needs a frame.
… That offers Good Chain / Crankarm Alignment
This is a tough one to nail down in advance. On chain alignment, you can come close during frame selection but you’ll never know for sure until you actually fit a motor into the frame, along with an assembled rear wheel so you can drape the chain and figure out how it lays.
As to crankarm alignment… thats one you will have to work out once you have a bike on a stand during the build. The key is to remember that your desired final result is to align the pedals directly underneath you… not the crankarms. Focusing on the pedals gives you a couple of extra options over and above finding an offset pair of arms to even things up. I have used uneven-width pedal spacers for some big changes, and different washer counts on one side or the other (from zero up to two) to move the pedals an additional 1.5mm to 3mm in either direction.
Generally speaking for BBSxx style motors with a large secondary housing located where the chainring ordinarily resides, you want a chainring with an inward offset that helps with chain alignment.
You also don’t want to overdo the size of the ring. Generally, “smaller is better” thanks to the rules that go along with riding a mid drive ebike (See below). You don’t want to pick a big ring unless you know exactly what you are doing with regard to gear selection and chainline. 42T is typically considered ideal unless you are riding singletrack. You go as small as you can get away with in that case.
Do a little shopping and you’ll find quality offset chainrings from the usual big name players aren’t cheap. Especially post-COVID. Here’s a new one I found recently on Amazon that offers about 15mm of offset and is well constructed. The offset looks to be more than that simply because the alloy used in construction is so thick.
I bought this ring and it appears a solid alternative – with a great tooth profile – for about half the cost of the other high end rings.
A beefed up chain is often overlooked and just as often results in an Epic Fail. You can’t run a powerful mid drive and expect to use the cheapo chain you already have on your bike. Whatever you do, don’t use a cosmetic (painted) pretty chain, or one of those pricey skeletonized weight-weenie chains. Instead, spring the bucks and buy a proper strong chain.
I run 11-speed systems with a KMC e11 chain – the KMC ‘e’ line is specifically designed to take a mid drive’s punishment. These 11s chains are brutally expensive (today’s price is over US$47), but this is part of the cost of admission if you want to run 11s and a high powered motor that doesn’t snap chains (or wear them out really fast). 11-speed is a wonderful thing to have on an ebike – particularly on a bike you pedal instead of throttling – but the cost of durable 11s drivetrain parts is a serious deterrent.
The story gets a lot better if you are using an 8, 9 or 10-speed setup. The SRAM EX1 ebike chain is used for their (hideously expensive) 8-speed EX1 mid drive-stressed drivetrain system. Here’s the thing though: That chain has an MSRP of US$28, and is usually sold for about US$25. The link above to Amazon has it on sale right now for US$18.95.
It gets better still: The EX1 system is 8-speed, but the chain is sized for a 10-speed system. That means you can use this chain on 8-, 9- and 10-speed drivetrains. Since 9s is probably the ideal sweet spot for mid drives, this chain can be considered almost everyone’s inexpensive default. To sweeten the deal, the chain comes with 144 links. So it will fit everything but a longtail without having to buy and section two chains together.
This one is quasi-optional. A quality derailleur is always a good thing. Especially if your alternative is something like a cheapie Tourney or similar.
I use a SRAM GX 2.1 long cage rear derailleur. This is not meant for a 1x drivetrain but if you just use a narrow-wide front chainring, you’re fine. At over US$100 a pop this is not a low cost option, and one more reason why you need to know you want more gears and more finely-diced cadence options to bother with 11-speed.
I have found two I consider to be stars:
Box Components Prime 9 I have two bikes with these, including my most recent build: The Apostate. My preferred version is the Box Two Prime 9 Extra Wide, coupled to their Box One single shifter, which is tailored for ebike use. The Extra Wide part refers to extra wide range on the rear cluster, which in English means Big. You can go up to I believe a 50T rear cluster with one of these. Combined, shifter-plus-derailleur is about a US$185 solution. I like it better as a premium option because… it shifts spot-on, was super easy to initially adjust and runs silky smooth.
Microshift Advent I like the Long Cage version, which runs US$60 and is meant for 2x systems but works fine on 1x. The Pro shifter is single-shift like the Box, and costs a whopping US$29. This setup is significantly cheaper than the Box. It works just a little less slick, and the fit/finish is more… workmanlike… but its nothing to complain about given the price range its in.
I have to say I like the adjustable clutch on the Advent better than anything else I have ever used.
I have mentioned but not explained why single-shift is needed for a mid-drive so here goes: Shifting under power is a Very Bad Thing. If you shift a bunch of gears at once, as is easily possible with a standard trigger shifter, its Way More Bad. If you are trying to snap your chain as quickly as possible (or taco a chainring or cog), thats how you do it. Single-shift shifters only allow one gear shift per trigger pull, so you can’t screw up. So either learn to carefully shift one gear at a time (certainly you can do that, as I do on my older bikes) or buy something that eliminates the issue.
Put simply, you want durability. Forget about light weight. You want all-steel cogs, preferably pinned together into a monolithic block. That block distributes the force across the cassette body/freehub underneath so you don’t dig a trench into the poor thing when you hit it with a shipload of watts.
11-speed The Sunrace CSMS7 is an all-steel 11-42T cluster, pinned together. I haven’t found anything else that is all-steel in an 11-speed. These clusters are often tough to find in stock and there’s no telling how long the link above will remain valid.
9-speed For bikes that don’t require a lot of range, you can’t beat the Shimano HG400-9. They are found in a range of tooth counts – my favorite is the coated 12-36T. They are dirt cheap and functional. All steel except the smallest cogs, and pinned together. Nearly indestructible and easy on the cassette body.
And its cheap with a US$35.99 price at the time of this writing. Unbeatable for a 9-speed mid drive build.
Rear Cassette Body (Freehub)
Whatever it is, it needs to be steel. If not, with an unrestricted DIY mid drive you’ll dig into it like its made of cheese. This is a big deal. I’m only devoting a couple of sentences to it, but thats because there’s just not that much to say. If you want to avoid tearing up this rather expensive and possibly difficult to replace part, use one made of steel. Period.
With all the talk above of strong chains, steel cogs and steel clusters, you can see where this is going I bet. With all that durable hardware we are reinforcing the drivetrain further and further down the line until we find the next failure point. After we get to the surface of the cassette, the next thing that breaks are the pawls inside the freehub. Whats a pawl? Here are a couple of pictures where they are visible:
The little things sticking out on the end are ‘pawls’: ratcheting couplers that hold the hub firmly while you and your motor apply force to the rear thru the chain. If they give out, the chain ‘freewheels forward’ and you lose the ability to apply force to the rear wheel to make it go. Mid drives putting out big power put big stress on these poor little pawls, and they can die as a result.
Its not hard to see why. All torque is transmitted through those pawls. What you need is more points of engagement. You can find 4, 5 and even 6-pawl freehubs. You can also buy quality rear hubs that can take this level of abuse (I hear Salsa makes some, as do Sun Ringle). You can also change the game and go to a different kind of mechanism that is effectively indestructible to a mid drive…
Bike Radar did a good piece on freehub construction so I’ll just link to that article here and let you read the details, and the comparison of pawl vs. ratchet. So far as I can tell across several wheelsets and several thousand miles, the DT 350 hubs with standard 18T and 24T ‘Hybrid’ ratchet mechanisms are effectively indestructible.
So we’re walking the points of failure back still. ‘Under’ the inside of the cassette mechanism is the hub, spokes and the rim itself.
This is not something anyone wants to hear, but if you want a trouble-free mid drive you put on a quality wheel built for it, by someone who knows what they are doing. This is not cheap, hence the reason nobody wants to hear it. And you may be able to do without. Heck… a lot of Mongoose Dolomite conversions are out there and running just fine. But if you expect to pour on the miles and keep doing so for years, trouble-free. Well, your money will be well-spent on a beefy wheel.
Lets take a typical 26″ example. I really like the SunRingle MTX39. It comes in 32- and 36-hole versions. At US$60-90 each they are not cheap, but also not crazy-expensive, either. Its ridiculously strong, but isn’t light weight.
If I want to blow off the budget and go for strong, lightweight (and tubeless) a DT Swiss FR-560 is a winner. I have them on 26″ and 29″ wheels, and they are also available in 27.5. But at about US$150 a pop you have to want em pretty bad.
Next, what about the spokes? Choose good, strong ones. Sapim Strongs are an excellent choice. So are DT Swiss Champions, or DT Competitions. If you are made of money, DT Alpines are pretty awesome, too. These spokes as a body are not the great big 12-gauge spokes you see on some imported Asian rims. the European manufacturers substitute quality materials and smarter engineering and don’t need that massive construction, but they still provide superior strength.
And lets not forget the nipples! Spoke nipples that is. Once again, choose strong ones, not light ones. That means no alloy. Use the brass ones.
Don’t Ride Like a Dumbass
Build it as smart as you want, but if you do bad things you will get bad results.
In the last few months, I’ve made a few changes to my standard on-bike tool kits. Lets take a look.
Things have changed a little since I originally wrote up my full size tool kit in late 2020, and my minimalist tool kit a couple weeks later. The changes are not big but when you are talking about risking your ride turning into a walk – especially in rough, remote terrain – its worth bringing up the things I have changed.
The Core Kit Items
Unless noted otherwise, the changes here are the same for both my full and minimalist kits. Lets run down the main players on the small kit first, so you don’t have to go and refer to another article to get the complete contents.
The Patch Kit
As I noted in 2020, Rema Tip Top cold-vulcanizing patches have been the gold standard for decades. And that is before I started using them in the 1970’s. They are essentially unchanged today. If you just want to buy what you need, then the Rema Large Touring Kit is the way to go. At present its a whopping US$7.15. However, I do it a little differently. I take an empty Costco pill bottle with its locking lid, and then I add a slew of my own patches, along with a snip of special sandpaper and a much larger tube of cold-vulcanizing goo. This gives me a more capable patch kit in a better, stronger container. It is not the no-brainer that just buying the pre-made kit is, though.
The Tire Levers
As was true in 2020 so it stays true now: After trying many alternatives, the Park TL-6.2 tire levers are the ticket. You can see them rubber-banded to a patch kit bottle above. They’re superior because they are metal, with a sturdy-enough-to-withstand-use plastic coating.
A Tire Patch
The Park TB-2 Tire Boot remains the standard and one is always found in my patch kit just in case. This is just a great big gooey patch meant to be applied to the tire and not the tube. You use one of these if you have some kind of major slit in the tire casing that gives it the tire equivalent of a hernia.
A stubby set made by Bondhus metric wrenches is in most of my kits (some of the bigger ones get a long set). These are made of high quality tool steel and inexpensive. You don’t need a whole set so if you want to shave weight or save space, you can buy these individually or just buy a set and include only what you need. However an extra piece of steel can be a handy pry bar. You never know…
A Pocket Knife
A pocket knife is one of those just-in-case items that has no specific job, but can come in REAL handy in so many ways. A Kershaw Shuffle is a good quality, inexpensive folder that incorporates flat and Phillips screwdriver bits. A.G. Russell’s Featherlite One Hand Knife is lightweight and handy for only about US$35, and their ‘Simple 3″ Lockback‘ is a bit less than half that price. Or how about a Slidewinder for ten bucks? Substitute in a multi tool for greater functionality (I saw a Leatherman Bolster on sale in a local Costco recently for only $39.95), but that is expensive and could make your tool bag a bit crowded.
I carry these outside my toolkit, usually somewhere I can grab quickly. The idea is if you hear that awful hiss-hiss-hiss sound as your tire rotates around a nail or similar, you stop the bike, jump off, grab the pliers which are in a quick-grab place and pull out the offending nail. Speed counts on this particularly if you have tire sealant like FlatOut waiting to do its job once the nail is removed and you spin the tire.
Its entirely possible the needlenose pliers can be done without depending on how you feel about the first item on my New Stuff list below.
7 1/4″ (180mm) size is my favorite for a bike tool pouch, although I also have the two smaller sizes (150mm and 125mm). The 180’s are ideal in my opinion. Small enough to use on a rack bolt, big enough to use on a pedal, or even an axle bolt.
These tools are spoken of in hushed tones by the folks who have been turned onto them, and I’m no exception. Think of them as a kind of super Channel Lock style of pliers, except they are optimized so you have much finer graduations in your ‘channel’ widths, the jaws always stay perfectly parallel and you can really clamp the bejesus out of these things, so much so they can be used like an adjustable, open ended crescent wrench. A 10″ / 250mm set lives permanently in my car and is great for bolting stuff like trailer hitch bits down tight.
This tool takes up the same space as the former adjustable crescent wrench and is more usable since it is a pair of strong pliers as much as it is a wrench.
Over time, the T25 Torx wrench has gone from something only Magura used on their brakes to a sort of alternate standard among manufacturers. Particularly when it comes to brake rotor bolts.
As much as I hate to admit it, the T25 is a better tool socket than a simple hex. Formerly only kept in my bigger tool kits, Since my Squeezy seatpost clamp also uses a T25 on my Apostate I’m officially carrying one in even my minimalist kits.
Battery Powered Pump
A couple of years ago I began championing the use of a portable air compressor that could be slightly modified to run off your existing ebike battery. I still have 4 or 5 of them, and I have never had one fail. However after reading some success stories, and my own research, I’m ready to say I have found a couple of models that are worth relying on.
About a year ago I started doing remote beach runs where there is no land access for miles along the route. You either climb up the beach cliffs and leave your bike, you go swimming, you turn back or you reach your destination. No one’s coming to get you because nobody is out there and your cell phone doesn’t work. Since my ride to the jumping off point was a few miles of paved shared-use path, followed by a bunch of deep sand and then more pavement home, I found I now needed a pump that could be used routinely and regularly rather than emergency-only. So I started looking at pumps and their reviews.
I found out pretty quick that many pumps advertise long life but when you dig into exactly what battery is inside, you find there’s not much there under the hood. Maybe 800 mah. For a pump that has to inflate two *fat* tires at least once and probably twice during the ride, AND have enough left over in case of emergency, I wanted some serious juice in the battery pack.
I decided to try out the CycPlus A8 pump, which had good reviews and published their battery spec. Not 500 or 800 mAh. 2500 mAh. Thats the biggest I could find in this class of small portable pump. What remained unanswered was whether the pump was reliable and whether or not – like lumens on headlights – the claimed battery capacity was remotely believable.
After a lot of use without any failures, I can say it has proven to be reliable. I literally can’t run the battery down in use on a given bike trip. The same has proven true with its companion model, the cheaper, lighter A7 model that trades the alloy pump casing for plastic.
The A7 is also narrower and longer. When I needed a pump for The Apostate, I wanted it to fit in my handlebar bag. I found I had to go with the A8. The A7 was too long to fit in my chosen handlebar bag. Not the biggest deal in the world. The A8 fits perfectly and the weight on the bars is not noticeable.
A7 on the left, A8 on the right. Comparative sizes are not quite to scale. Pic on the right is a little smaller than in reality compared to the A7.
Most useful if you have a two-legged center-mount kickstand. A couple of regulation hockey pucks underneath your kickstand effectively puts the bike up in the air for service on either wheel. Ridiculously handy. Also if you are parking your fat bike on sand, the enlarged puck under your single kickstand leg can mean the difference between the bike staying up or sinking. Call this an optional item but if you can spare the space one or two pucks can be a huge convenience.
Gone But Not Forgotten
This is what was once in the toolkit but is now gone/replaced.
The Knipex pliers take the place of the adjustable crescent wrench.
Now that I have an on-demand air compressor, I can kiss goodbye this ancient, single-use technology. That means no more cartridges stashed everywhere I can find a place to fit another one, and no more cartridge head
Manual Backup Pump?
I’ve worked with the battery powered pumps listed above enough to finally cut the umbilical cord to my backup hand pumps… but if I can carry one without too much difficulty I will. This is one habit that is very hard to break for someone like me who is so invested in having redundant backups.
I think the Knipex will also do this job, but my US$9 needlenose pliers are often out in the open in a MOLLE slot outside one of my packs. I don’t know for sure if I want to hang a US$60 set of fancy German workmanship out in the same way. So long as I have the space I’ll keep the needlenose’s on the payroll. But really if we’re being a weight weenie, I can find a way to safely secure the Knipex’ and get rid of the pliers. Or attach a multi-tool to the exterior of a bag perhaps and make my emergency tire pliers handy thataway.
Well thats pretty much it for the tool kit. Not the most exciting topic… until something breaks and you’re sitting on a rock trying to fix it.
In Planning, I opened by saying Preparation is Everything. With that said…
"Everyone has a plan until they get punched in the mouth."
-Iron Mike Tyson
Yeah. Lets talk about the reality check that is coming, once you actually ride the bike you just built. You learn whether what you thought would work actually does. More than likely, something will not work the way you’d like it to.
It won’t be a catastrophic problem, but this is a custom bike and you should expect a do-over or two to make it exactly what you want. This is how I wound up with the materiel and experience to write Musical Chainrings.
On that subject (bicycle gearing), over time that inevitable uncertainty has worked out in my favor. I know I am going to need some time in the saddle to figure out exactly how I want to gear any bike. I may also be surprised when I get a look at actual versus expected chain alignment. Thanks to Tyson’s Law, I have plenty of stock on hand to play around with and get it right.
You have to plan for and budget for this final step. Not necessarily for chainrings. There are a variety of typical culprits.
There is a pretty common hit parade of things most likely to need a tweak. They all have something to do with the human/bike interface: How comfortable the bike is to you when you ride it.
Is their width comfortable? What about the angle? Your wrists feel OK after awhile? Need a rise on the bars? You’ll only be certain you got it right after riding the bike.
For the Apostate I put on a 760mm titanium flat bar. I have tried to use this very snazzy handlebar on a half-dozen bikes over the last few years, and was never happy with it, so it went back to the parts pile. Having had the Apostate on the road for a few months now, it looks like I finally found a permanent home for it.
This is surprisingly important for rider comfort, and is perhaps the part I most often change after a new build hits the road. A longer or shorter stem can make a world of difference in comfort depending on what reach to the bars best fits you and your riding position (seat height relative to bar height also plays a role, so once again you need to be on the actual bike to understand what works best). A stem at a different angle can raise or lower the bars for a different improvement than changing the reach with stem length.
No matter what... do not use an adjustable riser stem. The kind that has a hinge you can supposedly bolt down so its safe. I know of two separate instances where they broke loose (thankfully I was not the rider). Both under heavy braking. Want to keep your teeth? Use a fixed stem with a set angle to raise handlebar height.
For the Apostate I tried an 80mm stem with a 6 degree rise. Based on measurements from other bikes, I knew this was likely to work. But once again… you never know until you ride it.
Once I did, my posture naturally gravitated to holding the bars with my thumb and forefinger; not naturally planting my upper body weight on my entire palm. I needed a big change, and so I grabbed the biggest change I had: a much longer 120mm stem with a 45-degree rise. This raised the bars as much as was reasonably possible (about an inch and a half) while not really moving the bars forward much (which would increase my reach and make the problem worse).
After riding it for a week, it felt better, but I still had to think to put my hands down flat on the bar. I hadn’t gotten it quite right yet. I needed to reduce reach a bit while not affecting handlebar height.
Since I was pretty much at my best result on the stem length and handlebar height, my next step in fitment moved from the handlebars to the seatpost, where I knew I had a little room to maneuver, so to speak.
Worth noting: I could have stayed at the handlebars and changed the bar to one with a pullback of some kind. But I wanted to keep the bar flat and straight on this bike so…
If you are having reach or posture issues, one of the tools at your disposal is to change your seatpost. Some have a setback, where the saddle is mounted aft of the seatpost tube itself. Others have no setback and the rail clamps are directly over the tube. The difference moves your body forward or backward depending on what type you use.
I try to solve fitment issues with handlebars and stems. Changing seatpost setback is usually a last resort (and if you have a suspension seatpost, changing that expensive part is usually off the table as an option).
For the Apostate, a vintage 350mm Kalloy Uno came with the frame. This venerable post has been on the market for decades. It is a no frills, sturdy option. It turns out a 350mm post, with a bottom set near to matching the frame’s bottom edge (still well within its safety limits) was perfect for my pedal stroke. Winner winner chicken dinner.
Or not. As noted above, after riding it for a week I felt I still needed a small change, and it seemed like it would have to be a seatpost change.
The alternatives left were scooting the seat forward in the seatpost clamp (minding the limits scribed on the saddle), and changing the post to one with no setback. Since I was already at the forward limit of the saddle, that meant a different post with no setback. I did that in an over-the-top way, which moved this modification out of the ordinary and into the Afterword section below. We’ll discuss details there.
My original Kalloy seatpost had a ‘setback’ that moves the seat’s mount back behind the post’s center axis. The post I replaced it with has no setback.
You won’t know if it works until you sit on it and ride for awhile. But, you don’t have to start from scratch, either. What you like on another bike is liable to work again. I know that for bikes I pedal hard, I like narrower saddles. I knew I liked the WTB Volt (taken off of my Surly Big Fat Dummy) on my GG Smash enduro bike.
So I put on another Volt (I scored the much nicer Chromoly version on a clearance sale) and its fine. No changes necessary. You may not be so lucky as saddles are notorious for not being quite right without some trial and error.
Again… this is about comfort. But budget is a factor as well. I tried going with a more or less period-correct option via some old cage pedals with mtb clips and straps. I had them on a shelf collecting dust, and thought this was a great place to put them back into use.
Wrong answer. Some things are better left to the past. Toe clips are one of them. I only had to fumble getting back into them once (I’m not cleating in here) to remember how annoying that was. Fortunately for my budget I also had a pair of perfectly good, cheap flat pedals on the shelf, which I put on.
And I still wasn’t happy. Again thankfully for my budget, my Smash is stored with its pedals off, and those pedals are Pedaling Innovations Catalysts, which are sort of monsters, but I have several sets. I really like the ability to support my arch, in a mid-foot position that benefits from a stomping pedal stroke.
So on they went and … perfect. I’ll use the cheapie flat pedals on the Smash. For now.
Finally, I built a bike I did not need to play musical chainrings with to get it geared right. Some of that was luck, some of it experience. The 40T Lekkie I used – which requires a special motor cover to be substituted on to fit – was a big ticket item, but its the smallest chainring available that would give me the offset I needed to get excellent chainline on this build.
That chainline was figured out in the Tinkering phase, when I had only the frame, the motor, a wheel and some of my spare chainrings to play with. Chainline is dead straight back to the middle of the cluster, and the gears I am comfortable riding in on this bike are the middle ones as well. One and done. For once.
So… maybe Planning Really is Everything.
The Apostate pictured in my Day 1 ride didn’t stay the same. Most of the changes are documented above. But things don’t always fit into neat little categories. What unique bits did I end up changing or prettying-up?
The battery solution on this bike came out great. The frame fits a certain type of ‘in-triangle’ battery pack, and of those packs, the Wolf Pack from Luna Cycle fits as if the frame was made for it.
However, clearances are tight. Particularly on top where it really matters. It was clear even during test fittings I wanted to keep this battery permanently on the frame and remove it as infrequently as possible. Ideally: Never remove it.
Not just because there isn’t much room to work with in terms of getting the thing off of its (super strong) magnetic mount. That strong magnet, versus the rivnut bottle bosses on this vintage frame… worry me. You have to apply so much force to remove the pack (or move it in any way forwards or backwards), I’m concerned something is going to bend (the mount) or break (one of the bosses tearing loose from the frame). There’s likely no coming back from a failure like that on an aluminum frame 23 years old and counting.
SIDEBAR:Why use the cinch straps if the magnet is so strong?
The straps provide additional stability and support. I want to do everything I can to take as much stress off of those two little rivnutted M5 bosses in the frame, which otherwise are holding the entire 9-lb battery on their own through all manner of road and trail shocks.
Initially, I used three velcro cinch straps to nearly cover the pack, and also stabilize the magnetic mount as much as possible. Later on, I decided to take advantage of two of the three slots on the battery side’s mounting tabs. These exist so hose clamps can literally clamp the battery permanently to the frame.
The clamps further reduce the reliance on the bottle bosses to do all the work of holding onto the pack. I had already padded the underside of the mount with a thin pillow of red silicone tape. The hose clamp makes no contact with the actual frame thanks to the mount width on one side, and the wire tunnel for the shift sensor and main motor harness cables on the other.
Those clamps also help reduce the potential of battery theft. Sure, nothing is going to stop a determined thief, but the hose clamps – and I made a point of not hiding them for this reason – make it clear to anyone looking that a few minutes (or an angle grinder) will be needed to get that pack off the bike. There isn’t going to be a grab-and-go theft. That fits in with the very limited likelihood of leaving this bike outside at a shop, locked but unattended.
If someone tries to steal it anyway, once a thief shears off or unscrews the hose clamps, they’ll be confronted with that magnet. I bet it will take some time to realize whats holding the battery so tightly. And once that realization dawns, they will have to figure out how to get it moved just right to angle it out of the frame.
Thats time I can spend setting bear traps, digging pits and buying a baseball bat.
I also used velcro to ‘face’ the cinch straps. This holds them together – really only for cosmetic purposes. The straps don’t move once tightened down. The facing (on the sides and the top) just makes the velcro present a little better; keeping the graphics on the battery from bleeding thru in the gaps between the straps.
The Condor Deployment Bag is something I use on almost all of my bike builds. Its easy to adapt into a secure handlebar mount, its small but still the perfect size for a tool bag that can also hold a wallet, phone and keys. These bags are my go-to for hiding wires – and especially controllers – on my 2wd bikes.
The original brown bag was replaced by a black one I also owned – when I finally found it.
Having several of these on hand, I simply switched from a brown one to a black one. The reason is straightforward: black wires blend in better when they are running along a black bag. Note that in some of the photos you may see a lot of wire stuffed behind that bag. I didn’t cut down the brake hoses to size until the very end of the build and test ride process.
This was a big change, but not for an overtly obvious reason.
The vintage Kalloy Uno seatpost that came with the frame worked great. Except as noted above I had reach issues. I had already moved the seat forward, and I did not want to shorten the stem as that would create other issues. So that limited next steps in terms of fitment.
I didn’t need much reach reduction, so I decided to do a seatpost with no setback. My first thought was a Thomson Elite. Which is a great product but not a trivial purchase at about $115. Since I was in that league in terms of cost, I decided to try a dropper post. They all have no setback. A dropper would be handy for all the reasons droppers are handy.
Also, the frame introduces constraints. The post can’t be super long. 350mm is the right length for a seatpost when fit on the frame to my anatomy; any longer means it protrudes down towards the shock, where the potential for contact is worrisome. Droppers tend to be in the neighborhood of 450mm long, so I wanted to find one with minimal drop. Those posts tend to be closer to 400mm. Also I didn’t want to blow the already blown budget, and a really good dropper costs big money.
I found an interesting option that would be an experiment of sorts, and decided to try it: I bought a PNW Components Coast dropper post, with external cable routing. I could have done internal cabling but a cable coming out the bottom hole in the seat tube could once again be a contact risk with the shock.
Why is the Coast an experiment? Because it is a – unique on the market – suspension post as well as a dropper. Advertised motion is 40mm (it can be more) and its a weird choice because this bike has full suspension already. My reasoning behind doing this – and my results – are enough for a full blog post all by themselves so I’ll just say I did it and it worked well.
As a dropper. Jury is still out on whether it is also an effective suspension feature, but it does seem to work for me in an unusual sort of way. Stay tuned for a separate post on this oddball idea and result.
After all was said and done, I did find a way to test whether there was risk of the seatpost hitting the shock: I removed all but about 20 psi of pressure, which let me easily compress the frame by hand, and observe the result. It turns out, for my frame, there is no risk of contact. Perform this check with yours to learn your result.
This one was pretty straightforward, but boy was it frustrating. I have had occasion to lock the bike up outside a store. The Salsa quick release seatpost clamp that came with the frame carried the usual risk: It makes it easy to steal the saddle and post. Since I am using a US$170 dropper and a US$95 saddle. thats worth taking steps to protect.
With a dropper, there is no longer any need for a QR clamp. So time for a fixed collar. I chose a Bike Yoke Squeezy in 35.6mm size, which turns out to be the wrong size thanks to a mistake on my part. Hint: Take the seatpost clamp off and measure under it. Not below it. This frame has two external seatpost diameters, which is invisible if you leave the clamp in place.
Why the Squeezy for a post clamp? It was a whim. The Squeezy is a bit of a unique animal and I wanted to try it out. Its a neat idea and well-made.
But there was that sizing issue, which I was only able to temporarily overcome with some shimming. I ended up finding a basic 34.9mm Axiom seatpost collar in my parts pile that I made work. Its an unremarkable part not really suited to this build. Still, it was handy to just install so I could move on to the next job … and wait for my annoyance at myself to subside so I could spend another US$35 for the correct 35.0mm clamp. Its on. It works. It holds my weight over time with no shifting. It looks great.
The Squeezy defines low profile. Note the very light torque specification. The T25 socket adds a hair of security without requiring an additional tool in my onboard toolbag.
The Wire Harness Tube
This was a unique need for this build. The usual preferred solution of a battery bag in the triangle didn’t work on this frame. Not so great news, as you use the battery bag to hide wires. My best solution to hiding otherwise bare wires was to enclose them in a pipe that more or less matches the frame.
I originally used cheap red PEX pipe purchased locally for about the price of a candy bar. I ended up not being happy with the red color and did a spiral wrap of red silicone tape to get a better match. In a short time it darkened to be a near perfect match to the frame. But it also had a few problems:
The tape was just not durable. I had rips and breaks in it – more than in the picture above . Also, I had cut the pipe a bit too long. When turning the bars to an extreme, the fork poked the top of the tube and pushed it to one side or the other.
The solution was to replace the pipe. I used a length of furniture grade, red 1/2″ PVC – a better red than the PEX came in, so no tape. I had to wait a couple of weeks for it to arrive. Cost was about US$20.
The shorter pipe didn’t need as much in the way of fastening thanks to two things: Wraps of more red tape around it provided sticky bumpers that hold the pipe to the frame under the pressure of the hose clamps and the velcro straps. The biggest benefit was the shorter length preventing any contact from the forks. So there’s no longer something trying to push the tube out of line all the time.
The wire tunnel is not a perfect solution, but the alternative is bare wires and zip ties.
So… to paraphrase George Lucas, a bike build is never finished. It is abandoned. And so, for now at least, we abandon the tinkering, building and perfecting of the Apostate. I’m sure I’ll do something to it again as time passes, but for now its time to just do to it what is meant to be done to a bicycle…
We accomplished a lot yesterday. What do we have left? Only one major component is left to install – the brakes – and then some final mopping up. We’re almost done.
Put On The Brakes (Literally)
We have already completed a part of this job: We put the brake rotors on with the wheels during Day 1. Now, we add the brake calipers that grab those rotors. We’ll mount calipers to the fork in front, and the frame in back, with the brake hose coming up from each caliper to the handlebars, where the levers are attached. This will be a lot simpler than it could be as hydraulic brake kits ordinarily come as a set with everything attached together already.
For this project, we chose a small 160mm rotor on the front wheel and a 180mm for the rear. A given bike could be built with various combinations of rotors. A brake caliper adapter lets a generic brake kit match up to any rotor size. How to pick the proper adapter is a common question, so let’s take a short detour and explain.
How To Pick A Brake Caliper Adapter
For almost all bikes, there are two different types of adapters: IS (International Standard) and Post. I’m going to ignore some of the fringe products like flush-fit, which you’ll probably never see on an ebike conversion/build.
International Standard mounts have two unthreaded M6 bolt holes, (spaced apart 51mm, center to center) facing horizontally, that pass a bolt through into a threaded adapter. The brake caliper then bolts to two top-down, vertically facing holes. Our project bike has a typical rear IS mount. Here it is, both before and after the brake caliper adapter has been installed.
Figure 1: Rear frame IS brake mounts, bare and with adapter installed.
In the right picture above, that is a Magura brand adapter. They handily have the adapter type printed right on them. You can see the model is QM-10, which is not particularly useful here (its an old part number… I dug it out of my parts pile for this build). What IS useful is the size/type designation under it: ISR-180. That stands for an IS mount type, R = Rear and 180 means it fits a 180mm rotor.
The most important takeaway from this tidbit of knowledge is there is a difference between a front and a rear 180mm rotor adapter for IS mounts. The two are not compatible, and if you try to swap a front adapter to the rear, at the very best you are going to get a bad fit to the rotor. At worst the caliper won’t fit over the rotor at all.
Our project’s front fork is a model-year 2000 Marzocchi Bomber Z2 X-Fly. That old fork has (for 2022) a very unusual disk brake adapter for a suspension fork: an IS mount. Almost all modern suspension forks use Post type mounts.
Here’s a pic from my Smash’s front fork, which is an MRP Ribbon. You can see where the name ‘Post’ comes from as the two mounts look like posts sticking straight out of the fork at a 90-degree angle.
A Post mount adapter bolts straight down onto the threaded posts, which are spaced 74mm apart (center to center). Typically, a fork has “160mm posts” which means you can use a 160mm rotor with no adapter. I have seen some forks with 180mm posts, which means you don’t need an adapter with a 180mm rotor, but those are rare. Regardless, you want to KNOW what size your posts are if you have them, both front and rear.
Bolt the caliper directly to the posts on the fork. Just like the IS mounts, M6 bolts are used on Post mounts.
What Have We Learned?
Brake caliper adapters with IS mounts are specific to the front or rear.
If the frame or fork has two unthreaded M6 holes that you put a bolt through horizontally inward across the bike’s wheel, with a 51mm distance (center to center) between the two holes, that is an International Standard (IS) mount.
If the frame or fork has two threaded holes facing outward (usually that look like two parallel posts) with a 74mm distance (center to center) between them, then that is a Post type mount.
Post adapters are unthreaded. IS adapters are threaded.
Pick the adapter that is meant for the rotor size, mount type and front/rear axle that matches your wheel.
One More Thing!
As if the above is not enough, there’s one lesson I have learned that has served me well: Buy an adapter made by the same manufacturer who made your brake calipers. A homebrew brake caliper job often involves using washers here and there as spacers/shims to make up for a slightly wrong/bad fit of the caliper to the rotor face.
I have never had to shim a brake setup since I started matching caliper and adapter manufacturers. Here’s the thing: An adapter is often made with the manufacturer’s calipers in mind. So for example, Avid brakes are mounted with semi-hemispherical washers above and below the caliper (this is used to aid caliper alignment to the rotor). The lower washers take up vertical space. That space is accounted for with a slightly lower rise in an Avid adapter.
Try mounting a different manufacturer’s caliper on one – where that caliper was not intended to be spaced with those washers in mind – and it’ll be too short. You’ll need two or three M6 washers (or dedicated brake spacers, which are a precise thickness) between the adapter and the caliper to make up for that difference.
Or use a matching Magura adapter with your Magura caliper and everything bolts directly together with no messing around.
Speaking of which, rotors are by no means manufacturer-specific, but you may see a slight misalignment when mixing rotor and caliper manufacturers. So there is a case to be made for matching the manufacturer throughout the entire system unless you are willing to do some experimentation off on your own You may suffer through a little trial and error, but you may also find a perfect combination, as I think I have (I normally use Tektro TR-17 rotors but not on this particular project).
So, with all that said, for this project bike I need a front (Magura QM-43) 160mm IS mount, and a rear (Magura QM-41) 180mm IS mount.
Bolt the two adapters on, front and rear. Magura specifies 6Nm for the M6 bolts you will use to do this (they should be included with the adapter you buy). Magura adapters include bolts with a Torx T25 head. 6Nm for an M6 is a good number regardless of what brand(s) you buy.
Attach The Calipers And Levers
Once thats done, you are ready to bolt on the brake calipers. Once again, you use M6 bolts, but the standard 6Nm may not be where you want to be on the torque spec. More on that when we tackle caliper alignment below.
Before you do this, you need to spread the pistons inside the caliper so they are fully retracted. Depending on your brakes, you can do this with a screwdriver, or a brake block that came with your brakeset, or both. The actual procedure for this is illustrated in the Filling / Bleeding Video 2 below. You want those pistons spread wide for that first installation. After you have spread the pistons, if you removed the pads (not really necessary if you just used a screwdriver) put them back in.
Now you can mount the caliper. Do NOT torque it down. Thread down the bolts until there is only a very little play in the caliper. It should be able to slide sideways left to right with fingertip pressure. You need to be able to fudge it around a bit in our next step.
The brakes I am using come pre-assembled – the caliper is connected to the brake hose, and the brake hose is connected to the brake lever that goes on your handlebars, so it is a ready-to-run assembly. The brakeset has hydraulic fluid in the lines already and does not need to be bled unless you cut the hoses to fit your bike. This makes initial installation a lot easier.
After mounting the calipers, your next step is to provisionally bolt the brake lever onto the handlebars (don’t worry about routing the hydraulic hose just now. Thats for later). Since brake levers are manufacturer-specific with their own torque settings and bolt sizes (some are M5, most are M6 and the SRAM brakes that came on my Big Fat Dummy were actually an SAE size) I am not going to get into the bolt or torque spec for the lever. Refer to your manual for yours. Just get the lever on in more or less the right place, and only tighten so its barely held in place. You should be able to rotate it on the bars without effort, which you will need to do later on in the day.
Align The Calipers
With the brakes on the bike but not safe for riding just yet, we need to align the caliper so it doesn’t rub on the rotor, which it will when you do an initial install.
Take up the ‘slack’ in the brake pistons
In the auto racing world, brake pads can wind up getting spaced away from the rotor thanks to the torsion that comes with sharp curves and high speed flexing of the suspension. This gives you something called ‘knock back‘. The cure for knock back is to do some gentle brake pedal depression in advance of that corner you are rushing up to. This tee’s up the pads so they are right up there with the rotor again. Otherwise, your pedal goes to the floor and you need a change of underwear.
We artificially induced a form of brake pad knock back when we spread the pads during the caliper installation. Now that the caliper is on, we need to undo that. The procedure is the same as with a race car: Squeeze the brake lever a few times, and don’t worry that it goes all the way down to the handlebars on the first couple of pulls. Keep squeezing and proper lever travel will eventually come back.
NOTE: What follows is the 'brake whisperer' version of aligning a bicycle brake caliper. This is a lot more effort than most people go to, but it will yield perfect alignment on even marginal brakes, barring some sort of mechanical defect (like a warped rotor). It is almost a you-have-to-feel-it-to-get-it technique. I will try my best to write it down coherently so you can replicate it yourself. Here goes!
Lets align the back wheel first. Toolwise, you need to keep within arm’s reach whatever wrench you need to tighten down the brake caliper. Usually that is an M6 hex key wrench, or a Torx T25.
Either spin the rear wheel by hand or use the crankarms. Get an earful as to how much misalignment there is (your ears will tell you how much real quick). Now grab and depress the brake lever to clamp and stop the wheel. Keep holding the lever down so the brake continues to hold the wheel. Since we left the caliper so it had only light play and could move freely, that caliper is now sitting very close to its natural, proper alignment, and is holding itself there thanks to your hand clamping the brake lever.
Now pick up that wrench you set aside with your other hand. While still holding the brake lever, gently tighten first one bolt, then the other so now the brake caliper is just barely held in place. It is imperative you apply only the gentlest amount of torque to that wrench, because even a bit too much will cause the caliper to move and spoil your alignment.
When done with two gentle tugs on that wrench, spin the wheel again. Does the wheel come really close to rotating without any touch to the rotor? Since we only barely tightened it, you can now move first one side and then the other of the caliper side to side, just a hair, with your fingertips to try and eliminate all contact. The slight tension you put on the caliper via the bolt should still allow you to move it, and that movement will now stick. Fiddle with it front and back, gently, side to side until you have the brake caliper in the perfect spot, so it does not rub at any point in the wheel revolution.
If we have the caliper in a final position, since we have barely any tension on the brake caliper bolts, we need to – again, very slowly and gently – apply more torque, alternating from one bolt to the other. It is a good idea to physically hold the caliper and adapter with your thumb and forefinger, clamping it in place with your fingers while you do small wrench turns – maybe 1/16th of a turn or less (!) at a time at each go. After each adjustment, spin the wheel and see whether the caliper shifted a hair in the wrong direction. If so, try and correct with your thumb and forefinger, or back the bolt off just a touch until you can make an adjustment.
You may have to undo and restart the process a few times. It is not at all unusual for the caliper to rotate on its horizontal axis a hair – even on a caliper not using hemispherical washers. Don’t be discouraged by this. Just take it into account as you try (and likely retry) to get the caliper tightened down sufficiently so it is in place, not moving and not rubbing. Do it precisely enough and you will find that sweet spot.
When you do find it, that bolt is almost certainly nowhere near the 6Nm that is typical for a tight M6 bolt. It will be much less. I do not try to tighten the calipers down that tight. Applying torque like that makes it almost impossible to align the caliper with the kind of fine control I want. I have never had a caliper loosen so, anecdotally, you should be fine too.
Its worth mentioning that this procedure is being used with Magura brakes along the lines of what you see in Figure 4 above: No washers, no spacers. Just direct part-to-part contact. And I am often using 2.3mm thick rotors, which are very thick. Even thicker than the 2.0mm rotors Magura recommends for their calipers, which are in turn thicker than the 1.8mm rotors that are the standard for most of the rest of the industry. So this procedure is used to dial in a very tight system that has very little wiggle room in it. Still, it will work great for any system if you are willing to put the time in. And once its done, its done. It will survive wheel removal and reattachment just fine.
Aligning the front caliper is the same process as aligning the back. Only one additional observation is necessary that applies to both wheels: given the low torque on the caliper used here, you could be forgiven for coating the threads with Vibra Tite gel (NOT Loc-Tite). I use it if a tube of the stuff is within reach. Otherwise not. So its not something you have to do, but it can’t hurt, right? Don’t lose any sleep if you forget to use the stuff.
Route The Brake Hoses
This is effectively the identical process that was described in Day 2 when we routed the shifter cable. Once again the exact process varies greatly by bike, and you’ve already seen how I am going about it on the Day 2 build. So we won’t re-cover the same ground. Below in Figure 5 is a pic showing the anchor points for both brake hoses. Numbers 1 through 3 are identical to the shifter cable that is on the other side. #4 is a simple zip tie wrapped and anchored by crossing the V-brake post. Modern front forks will have some sort of dedicated, manufactured anchor point at roughly the same spot.
Be sure you leave enough slack in the front so there is adequate room to turn the handlebars to their fullest extent without any tugging on the brake hoses. Need an example? Look at another finished bike 😀 . The hoses need to be long but not too long.
The picture below shows the temporary brake routing I used in the first few weeks as initially I did not shorten the brake hoses.
NOTE: When routing the hoses, they will be longer than necessary. Route them so the excess hose is sticking out in front of the bike. From the caliper forward/upward to the handlebars, the hoses should be tied down as you expect them to stay.
Shorten The Brake Hoses
This is luckily one of those times when a video is the best tutorial, and we have a great one here. Again this is tailored to Magura brakes, but the principles hold across all brake marques. Its only 3 1/2 minutes long so watch it now:
Here’s what I do differently: I use a different hose cutter as shown in the tool list. I also would put on the cable molding cover, nut and olive BEFORE I stuff on the metal hose barb. The reason for this is when you put the barb in, it often spreads the housing of the cable just enough to make it impossible to thread those fittings over the now-finished hose end. So just put them all on before pushing the end barb in.
Additionally, I use the specialty tool (brake hose needle driver) that carefully drives the end pin into the hose. Its a lot easier than hammering in the pin. Video 2 makes this process look easy as pie and it is seldom that. If you don’t want to spend the $26 for a specialty tool, yes you will get the job done by using the method shown in the video. For me, I never want to fight with a hose barb again and I’m glad I sprang for the needle driver.
Bleed The Lines
Once you have cut down the hoses, you have air in the hydraulic lines, which is very bad. You have to bleed the brake lines to get the air out. Here are two videos that show ‘the long way’. This is how you should do it at least the first time after cutting the hoses down. I am also showing you Video 3, which is much less messy than the ‘official’ instructions in Video 2. It is worth mentioning that the instructor in Video 3 is a Magura tech specialist. So its not like he is breaking any rules.
The only issue with this next method is you have to remove the caliper, which means you have to realign it per the procedure above.
And now for the short way. Use this method for a touch-up bleed down the road. You can probably get 90% of the efficacy received from a full bleed by doing it this way, which is much simpler and does not involve disconnecting brake lines and spilling fluid. Its also faster.
Note also that when I do ‘the long way’ I just use a syringe stuffed into the reservoir hole like is done below and do not bother with the expensive bleed bottle that is used in Videos 2 and 3 above. I use just a syringe with a hose and screw-on tip, a syringe reservoir and a bottle of fluid. No need for any fancy bleed kit.
Its time to start getting the handlebars set up in their final format. Now that the brakes are on, we’ve pretty much got a working bicycle here and all thats left is some tidying up. The only thing we aren’t going to do is put the grips on, and thats because the grips I put on often have to be cut off. So I want to wait until the last second to take that final step. Everything else should be put in its final position.
These are what you position first. Nothing is more important than being able to easily reach your brakes without having to work at it. So having them set up right is Priority #1. They go closest to the grips. Always. And everything is fit around them. You don’t move your brakes to a sub-optimal position to make up for anything else. It is done the other way around.
The next most important item on the bars is the shifter. Here again, you must have unrestricted accessibility. You also don’t want to have to change your grip to use it, so the shifter should be directly up against the brake lever. On an ebike, typically you have only a right-side shifter (for the rear cluster).
If there’s a shifter taking up the space adjacent to the brake lever on the right side, that leaves the left side for the throttle. I am assuming a thumb throttle here and will not get into the nuances of a grip or half-grip throttle as I never use them, so I don’t have much to say for them or about them.
One nuance of a thumb throttle that is often overlooked is ‘clocking’ the lever. You want to position the lever so when it is fully engaged, the tip of your thumb is comfortably holding the handlebars, and preferably the paddle is fully extended straight down. The reason for this? When you hit a pothole or similar road imperfection, if you are putting any sort of weight or grip on that fully depressed throttle paddle, your hand/thumb will bounce down thanks to gravity and inertia… and can snap that paddle clean off as a result.
If you clock the throttle so it is pointing down when fully engaged, then your body’s reaction to a terrain impact will just cause your thumb to slip off. The throttle snaps back to zero input. Maybe a bit annoying to have to re-engage, but nothing is broken. Maybe for you straight down is too much. Experiment with it to find out what works for your preferred grip on the bars, while keeping this fail-safe technique in mind.
Once that is done, this is what the bike looks like now.
Whats with the handlebar bag?
Well, in addition to being a handy way to store wallet, phone and keys, it also hides any excess wiring that I can’t easily get rid of. In this case, even though the wiring harness I am using is a little shorter than normal, it is still probably an extra foot longer than it needs to be. That slack has to get taken up somewhere. Likewise, there are wires connecting to the left brake, the right brake, the display and the throttle. In addition to the usual shifter plus right and left brake hoses. Thats a lotta wires.
I have found a handlebar bag – especially this particular molle deployment bag I am using here – is great at hiding that rats’ nest in addition to being a convenient dump pouch for what is usually in my pockets. The molle loops on the bag are perfect for running excess wire so it is literally integrated into the bag’s surface. In these early build pictures, I am using a leftover brown bag I had in my parts pile. A black bag hides black wires running along its surface much more effectively, and I switched to one later on for that reason.
Test Ride Time
Go on. You’ve earned it. Go for a ride. If you’ve done your job as described here, its ready. Sure, the grips aren’t on yet, but you can hop on and ride around the neighborhood. Start out slow. Engage the pedal assist. Give it some throttle. Figure out how it handles, keep things mellow. Oh, and wear gloves and a helmet. Some of my worst mishaps occurred on test rides that were supposed to be a 5 mph toodle around the neighborhood cul-de-sac and ended up with a faceplant. Right now you are a test pilot. Dress like one. At least a little.
Tailor The Motor Settings
This procedure will vary depending on your chosen motor. For this project, we are using a BBSHD and I have that platform down pat. I know exactly what settings I want and I have a tool to change those settings that I can plug right in.
Here’s the process I use. Once you’ve read thru this article, follow on to the sequel linked at its page top. I plugged in the Version 2 screens in that second article on this bike in a couple of minutes (shown below). These are the most neutered pedal assist settings I have in my toolbag. The gentlest stuff you can find while still retaining the ability to lay on full motor power with the throttle if its ever needed. Look to the linked articles for sterner stuff.
Clean Up The Wiring
OK so you were having fun riding your new bike around. Unfortunately there’s a bit more drudgery to get through. You need to finalize the battery wiring … at least you do on this bike because everything is out in the open. So we need to do something short, strong, neat and tidy that is also color matched so it doesn’t stick out.
Figure 6: The finalized exterior wiring. Bottom wire is AC Power to the motor. Top wire is battery charger input.
Here’s what we are looking at in Figure 6 above. First: the power lead that sends battery power to the motor. A BBSHD comes with two fairly long (roughly 35cm), separate black and red 12-gauge wires, each terminated in an Anderson Powerpole connector. While Anderson connectors are adequate, they are susceptible to water and far from your best choice, which is generally considered to be a water-resistant, spark-resistant XT90S.
It so happens the wireless Luna Wolf pack I am using also has a female XT90S built into itself, so the decision to use the more capable male XT90 is made for us by the battery.
The job was to measure thrice and cut once. I had to shorten the power cables running out of the motor just right so a similarly shortened 10-gauge XT90 pigtail could wrap around the frame at just the right length to be snug, yet removable without being so tight it would break something.
Since this power cable is in the worst possible place for collecting grit, grime and water, I went overboard on the protection for the connection. I used 3:1 marine adhesive butt-end connectors and surrounded the connection area with thick marine 3:1 adhesive heat shrink. This effectively waterproofed and armor plated the connection. I topped it off with a hand-wrapped spiral of frame-matching red silicone tape to lower the visibility of the thick wire. This also adds more protection and waterproofing. If I could have found a reasonable way to use the same red PEX or PVC tubing to further armor the connection I would have done that too. But as it sits, if something gets through all that its probably going to destroy the bike, too.
The battery cable was made almost the same way. Two short 12 gauge male and female XT60 pigtails were crimped together with marine heat shrink butt end connectors to make a short extension cable. No 3:1 heat shrink this time as I need this cord to be flexible. The loose end that will be attached to the battery charger is tucked into the velcro strap that is helping to lock down the pack onto the frame. What you can’t see in Figure 6 is the open female end of the extension cord is further covered with a waterproof cap made to fit the XT60 like these (also widely available on Ebay). I finished the job with a matching, protective wrap of red silicone tape.
Put The Grips On
My chosen silicone grips are 50/50 in terms of being removable. Half the time they have to be cut off, so they only go on at the last possible moment. That moment is now. We’ve got everything installed, laid out, positioned and generally nitpicked so we can put the grips on without worrying we have to take something back off. Further, we purchased as many parts as possible that use clamshell type attachment (the one exception is the throttle) so those items can be removed without also having to remove the grips.
For silicone grips like those I am using (Wolf Tooth Fat Paw), I have found some drug store denatured alcohol inside and on the grip is the way to go. Here is a video that shows removal and installation of a variety of grip types using various methods, including the use of alcohol.
My chosen end caps are the compression-plug type that screw on and off. Also, if you look at the final pics you will see I am using bar end extensions for some grip variety and a bit of added certainty my hands won’t come off the bars in extreme circumstances. When setting up placement of my shifter, throttle, brakes and grips I took into account the extra 1.5cm or so I would need to fit these extensions onto my 760mm handlebars. In fact, I chose bars a little wider than I like because I knew I would have these ends on, which effectively shorten the bars by placing the grips a bit further in.
Figure 7: The handlebars. Note the little lever hiding in between the throttle and brake lever in the left photo. We’ll get to what that is in the next ‘Perfecting’ post.
And we’re done. Holy crap. We’re done! We did it. We made a bike.
Well, really its not a fight. We’re moving forward pretty steadily despite a couple of time sinks that came in the form of a failed Tannus Armour installation, and a ‘peat-and-repeat motor installation where it took a bunch of time to get the cable routing off the motor just right. And speaking of motor cable management, thats where we will start.
We’re nowhere near done with the motor, but on this second day we won’t start there.
Since we bolted the derailleur on the bike as our last act yesterday, lets continue with the drivetrain and start today with…
Craft The Wire Tube
This is a component that is unique to this bike. That doesn’t mean it can only be done on this bike. But its an unusual element for an e-bike, so bear this in mind when you are building yours.
Usually (maybe even ideally) when you build an ebike you choose a frame that has ample room in the forward frame triangle for a battery pack. You secure this battery pack in a battery bag (Since we have already repeated the mantra of DIY does not have to mean half-assed enough for it to sink in, I will ignore the fact that some ‘builders’ use duct tape – or worse – to secure a battery in the triangle). Myself personally I really like battery bags, and I use them on most of my bikes.
Battery bags let you secure the pack on multiple sides, nice and tight. They also let you pad the pack so when you are bouncing around, your pack stays protected. You know what else they do?
They hide all the damn wires.
So, the Apostate’s 1999 Intense Tracer frame has the nearly unique and wonderful characteristic that it fits a Luna Cycle Wolf Pack almost as if it was made specifically for it. Not only was no battery bag needed… I couldn’t use one even if I wanted to. In the lead-up to the actual assembly days, during Tinkering, I tried all sorts of alternatives including different batteries (I have several that can either be pulled out of storage or off of another bike), the use of rectangular, strong cordura/molle bags and even jerry-rigged strapping. No alternative worked.
So that, as they say, is that. I can forget about having the luxury of a battery bag, where I can stuff all my loose wires and just run them thru slots in the bag, back to front with no one the wiser. I had to come up with an alternative.
I couldn’t do what I did with the Stormtrooper above as the most ‘red’ heatshrink I could find looks pink against the deep, fire engine red of the frame.
I decided to make a wiring tube – a bit of fixed plastic pipe clamped to the frame. I can run the main motor harness wire and the unused-but-still-dangly shift sensor wire through it.
Annoyingly, I did not take close-up pictures of the wire tube during the time it was created and attached to the frame. The tool used to cut the PEX pipe to size was a simple hacksaw and the pipe was cut while holding it by hand. The hacksaw went through it like butter.
This is another instance where a lot of prep time in advance of the actual build day was spent figuring out exactly how to deal with a problem. While cosmetically I wasn’t thrilled with doing it, functionally it worked very well to both hide the wiring and give it strong protection.
I was never happy with the look of the tape-wrapped PEX pipe, or its connection to the frame. Shortly after build completion I placed an order for different parts and did a different, better tube. Since it took weeks for the parts to arrive, many early ride pictures (particularly the ones in the Grand Canyon) show this original PEX pipe. We'll address its replacement in the Perfecting post.
Run Main Wiring Harness Through Wire Tube
With the wire tube in place, its time to run the wire harness up through it from the motor to the handlebars. Because the connection between the motor side cable and the harness will be in the middle of the tube, and the tube has been affixed to the bike, we need to do this in a particular order.
Feed the harness into the tube from the top, down to the motor. Feed it all the way in until it gets to the knot where the wires separate. This will leave plenty of extra harness wire sticking out, motor-side.
Connect the harness to the motor-side plug. Be careful to line up the little arrows on each plug housing to ensure everything goes together properly. Do this wrong and you can destroy your harness by bending the wire ends inside the plug.
For this build I am not using the shift sensor, which is the wire coming out of the motor with the yellow HIGO/Julet plug. Stuff it into the tube just ahead of the plug you just connected in Step 2.
Feed the harness back up the tube so there is no longer any slack down at the bottom and the wires now feed straight into the tube. Because you stuffed the shift sensor plug in ahead of the wire harness plug, that thick plug, which is almost the width of the inside of the tube, will drag the shift sensor up with it; keeping it safe and snug. When the shift sensor wire has extended fully into the tube you can stop.
You now have a fair bit of extra wire sticking out of the front of the tube. On some bikes, there won’t be a lot of excess. On others there will be a lot. We’ll deal with this on Day 3. Just let it hang for now.
As noted above, most bike builds will not use a wire tube. If you are using a battery bag, you can just run the harness up inside of and thru the bag. You can also use velcro onewrap straps or zip ties to run the harness wire along the bicycle frame tubing. Remember... zip tied cables all over your frame look cheesy. Avoid them as much as possible, but if you must use them, try to use colored ties that are at least in the ballpark of a match to the frame. Even a rough color match sticks out a lot less than say black on red.
Attach Display and Throttle To Handlebars
This step is here simply because it has to happen somewhere. This is a good time to get it over with. Attachment of the throttle, by necessity, involves slipping it over one end of the handlebars since its a single piece, tightened to the bars with a small metric hex socket. Displays tend to be a little more flexible, typically using a hinged attachment that makes them a little easier to install. Usually they tighten up with another small metric hex socket. Sometimes you’re unlucky and its a Phillips head.
For both pieces, just get them onto the bars in roughly their expected final position. Tighten them only so they are snug, but still movable. Do not connect them to the wiring harness yet. We won’t put on the grips and brake levers until tomorrow so what we’re doing here really is just ticking a box, so we can do our motor functionality test at the end of the day.
Attach Chainring To Motor
Here again, we’re just taking a relatively easy step that gets us closer to our goal. We need the chainring on so we can put on the chain, which will let us do a motor test.
Since we’re doing a Bafang mid drive motor, attachment of the chainring involves the use of five short M5 socket cap screws. As always I recommend you visit your hardware store and acquire upgraded stainless steel examples. Also – and this is pretty much true everywhere – DO NOT use button head screws. It is tempting to do so because the low profile button heads give a more finished appearance, but they are a bad choice on a bike for a number of reasons – all of which I learned the hard way.
A button head uses a smaller hex socket because of its diminutive size. So when torqueing it down (or removing it after time has passed) it is much easier to strip.
If a button head is stripped, you will need a specialty tool to back it out. If instead you had used a socket cap, a small vise grip could clamp onto the socket and has a pretty good chance of working.
A socket cap is much less likely to strip in the first place thanks to the larger size hex head.
A socket cap is rated to withstand more torque (see above).
The prohibition against button heads used to apply especially to M5 brake rotor screws, and after losing a couple of them I switched to M5 button caps, but in recent years, the industry has fixed that problem by using screws with Torx t25 socket heads, which solves the stripping problem. If you can find longer, stainless steel Torx M5-sized screws, those could be an option for fastening the chainring.
Tighten the chainring screws in an alternating star pattern. The torque spec you use should vary by the kind of screw you are using. Here is a table showing the different common metric screw material grades, and the Nm settings that represent a maximum for each. Keeping in mind we also don’t want to strip out the threads in the socket, I would not exceed 8Nm. The minimum of 7Nm on the chart should also work just fine.
While I am a big fan of never using a thread locker, as a properly torqued bolt doesn’t back off, this is one place where I have violated this rule. However you need to use the right kind of thread locker. Consider Vibra Tite gel. It is a vibration-resistance product with roots in aviation. It never truly dries. It just goops up the threads sufficiently so they don’t back off. I learned about it participating in shooting sports, where the old hands use it on extremely expensive – and delicate – optics that are subject to repeated, severe recoil impact.
If this thread locker is used, bolts will stay put. They can always be backed off with a simple hand tool without risking a seized bolt or a twisted-off socket cap.
Quick Chain Alignment Check
Do this BEFORE applying final torque to the chainring above: Just snug the chainring bolts. At this point, you can now use your final wheel assembly, complete with rear cluster installed, to check your final chain alignment. There is no need to actually install the chain. Just drape it over the chainring, and back over the rear cluster onto its middle ring. How does it look? This is probably the first time you can see for sure what your bike’s chain alignment is really going to be.
For this project, doing this quick check, I found my chain alignment was too far inboard to the frame. My Lekkie 40T ring provides a bit over 20mm of inward offset. Which is a lot as these things go. Too much in this case. I used a Lekkie 2mm spacer (which was included in my motor cover kit) to bring it out just a bit. I also used slightly longer M5 screws to make up for the spacer moving things outboard.
Luckily this simple spacer gave me a best-case solution without having to reinvent any wheels. Which I have had to do in the past.
If your luck isn’t so great when your turn comes, Here’s a link to the likely path to your solution.
The crankarms are the next logical step after fastening the chainring. Here again we don’t really need them on the bike other than to make some forward progress.
Crankarms – especially the square-taper variety commonly found on aftermarket ebike motors – must be tightened down by a torque wrench. Torque specs for crankarms specify to a range, typically, of 25-35 ft lbs. Even at the low end, thats tighter than you can guess at.
Especially because you are tightening down onto a tapered spindle (axle), for two reasons. First, the crankarm will slowly tighten down onto the spindle, going deeper and deeper, and you won’t realize it has bottomed out at the right place unless you are monitoring the actual torque being applied. You will be turning and turning on that wrench and watching the crankarm descending down, further and further and think ‘gadzooks thats got to be enough’… It won’t be. If you don’t go too little and tighten too much, you will smoosh your crankarm onto the spindle. The softer aluminum crankarm will spread as its jammed too far down onto the steel, and it will be forever loose (wobbly) once you make that mistake.
And of course, if you don’t tighten it enough, its going to come loose sooner rather than later. In fact, square taper crankarms will ALWAYS come loose, and do so faster the more you ride. They have to be maintained. If you are pedaling hard 30 miles a day on a commute, for example, you should check crankarm torque roughly once every two months. If you are riding around the block on a leisurely cruise every week or so, once a year should be fine. But make no mistake: It has to be done or sooner or later your luck is going to run out.
So… thats why you need that torque wrench. This is the first and maybe only time we will use the larger 3/8″ version, because the torque needed is too much for the little 1/4″ unit to handle. Worth mentioning: Its possible to use the larger 1/2″ torque wrench for this job, although its overkill. Still, if you are not down with buying three wrenches, two (the 1/4″ and 1/2″) will suffice.
For square taper spindles and both high end and low end alloy crankarms, I have found a setting of 25 ft lbs (30 tops!) to suffice. I know that Lekkie says 50-60 Nm (37-44 ft lbs) right on the crank extractor plate of the crankarm… I don’t go that hard and I have not suffered any ill effects from being a bit kinder and gentler to my bolts and (expensive!) crankarms. But I also keep on top of my torque settings by checking the bolts regularly.
How do I perform a routine torque Check?
I said this was crucial, and it is. So we’d better go over how to do it, since if done wrong, you will snap off the head of your crank bolt. Don’t ask me how I know this.
If you just set your torque wrench to the desired setting, then stick it in the socket and give it a tug until you hear a click, just the act of doing that imparts added torque to your bolt. So lets say you check it once a day (you won’t) and in so doing you give it that click once a day. A torque wrench either clicks when you reach the required torque or it clicks if you are already past that torque limit when doing a checkup. Yikes. That means once a day if the bolt has not loosened in between checks you are overtightening it a little at a time every time until … snap. Now you are screwed and you will literally have to take an angle grinder and cut your crank arm off to move forward.
Here’s how you do it right: Back off the bolt a hair. 1/8 of a turn is enough. Now you’ve loosened the bolt just a little, when you tighten it again the click you hear will be the torque wrench for-reals reaching the desired value. If this technique sounds familiar it may be because its used at any decent automotive tire shop, after a pneumatic impact wrench has been used to install your new set of tires.
Attach the Pedals
Again, we are just ticking a box and thankfully this is a pretty simple item. Or… is it?
As an admin and moderator on a couple of online ebike support groups, I literally cannot count the number of times I have seen noobs have a disastrous experience with pedal installation, or catastrophic failure after the fact from a botched installation, where the tragic flaw wasn’t recognized right away. So lets make something simple as complex as possible by looking very closely at it.
One Pedal is Reverse-Threaded
This one item is the cause of almost all pedal installation problems. You would not believe how many people don’t know this, and then cross-thread the pedal in whether it likes it or not. This results in the pedal threading in nice and tight. Until the now-shredded threads give out a month or two later, at which time they see the trashed threads and blame the manufacturer for making crummy parts. Yeah. No. The problem is the loose nut holding the wrench.
Having suffered through so many of these sagas, I was thrilled when in 2019 I bought my Mongoose Envoy and saw it came like this (see pictures below) from the factory. Obviously they’ve seen enough of the same mistake to try and do something about it.
So if you are trying to thread a pedal on and it doesn’t go easily right in… STOP, gather your wits for a moment, think about what you are doing and why the pedal may not be going in like it should, and remember the reverse threading on the non drive side. Then proceed.
You Can Always Tell Which Pedal is Right Or Left
Just by looking at it! You won’t need any stickers. Look at the left picture above and check out the threaded pedal bolts. You can just barely see the left pedal’s threaded portion, but you can see enough. Just above the threads, its ridged. Now look at the right pedal sitting underneath it: No ridges. This is a theme across all pedal manufacturers. Usually what you see is a single circumferential line around the left (non drive side) pedal. Here are the pedals I am using on the Apostate right now. Left on the left picture and right on the right picture.
See that? There is a line scribing the pedal axle on the left, no line on the right. Easy peasy.
Grease The Pedal Threads (Anti-Seize)
I believe I have mentioned what a good idea the use of anti-seize is, and why its especially useful when bonding dissimilar metals like the steel of the pedal and the alloy of the crankarm. Its also particularly helpful if you are going to be connecting and disconnecting a threaded part, as the anti-seize will protect those threads from galling while they are being screwed and unscrewed repeatedly over time.
Why would you be taking the pedals off? Well, on a bicycle that is going to be stuffed into the back of a car, the pedals stick straight out on both sides. Also thanks to the rippy, stabby little studs festooned across most mtb pedals, they are going to hang up on and tear into all sorts of things. Just taking the damn pedals off makes the bike amazingly easy to manipulate and move around inside of a car.
Can it be done with the pedals on? Sure. Can it be done as easily after taking 30 seconds to remove the pedals? You know the answer 🙂 .
Use Very Light Torque When Tightening Pedals
This goes hand in hand with ease of removal, but the benefits of doing this are not limited to a bike that has its pedals frequently removed. To the contrary, this is how you should install any pedal on any bike.
And no, this is not the advice you are going to get from most everyone else, everywhere else. I’ll make my case:
Its common to see torque specifications for a bicycle pedal in the ballpark of 40 Nm. Thats pretty tight. I never do this. Instead I use a pedal wrench and just give a quick, light tug to snug the pedal on when it bottoms out in the crankarm.
Unless someone helps them come undone, pedals will not work their way loose through normal use. That is why the left pedal is reverse threaded. In fact, the threading on each pedal, coupled to forward pedaling action, means pedals self-tighten as the rider rides (assuming the pedal bearings are functioning, but that is a rabbit hole we don’t need to go down; especially given the modern use of sealed bearings).
Given that pedals in good working order, used properly, cannot loosen: there’s no mechanical reason I have ever come across to use high torque on a pedal. On the other hand, I have repeatedly been thankful my pedals come off easily when I want them to – and only when I want them to – as a part of the routine maintenance, transport and wear/tear of a stable full of bicycles over many years.
So thread them on, put the right pedal on the right side, just give a quick tug on them after they are threaded on and fuggedaboudit.
Install Shifter, Chain and Adjust Derailleur
I have used the Box Two derailleur and single-shifter in the past. Since I am using a Box Two derailleur here, I decided to upgrade to the Box One single-shifter, with a matching Box One shifter cable kit. The Box Two shifter worked great, but the upgrade is not much more money and has a marginally better handlebar clamp. So I splurged.
Installing a shifter involves some standard jobs. I’ll cover those in brief and then note how this bike, because of how old it is, needed some special handling.
Unbox The Shifter
I find that I don’t have a picture of the actual Box 1 shifter I put on this bike, so I swiped a couple from the store page at Box Components where you can buy one for yourself (I got mine at Jenson USA).
Looking at this shifter above, the most noteworthy thing to be aware of as a new bike builder is the fact this shifter has a hinged attachment ring. That means you don’t have to pull off (or cut off as is often the case) the grips on your handlebars, should at some point in the future you need to remove the shifter, reposition it… whatever. That silly little feature – that seemingly has nothing to do with the intended functionality of a shifter – is a big deal over the life of the bike.
Box Components does not deliver the shifter as shown in the picture above. What you get is like what you see in this different shifter, below:
Put simply: you are given a shifter with the shifter cable already installed. this is a nice little timesaver I have come to expect from every shifter I have ever bought. They all seem to come with the cable. Thats great, but you need more than that. Here is a complete parts list for a plain vanilla shifter cable; completely installed from the shifter on the handlebars to the end of the cable sticking out of the derailleur:
A cable ferrule stuck onto the end of
The shifter cable housing, which goes over the shifter cable and all the way back to the derailleur and terminates in
Another cable ferrule. The ferrule snicks into a slot made just for it on the derailleur, where the cable continues on into its clamp, and is terminated by
A cable end crimp
While I have all of these parts in quantity in little cubbys in my workshop, I decided to buy the Box One Shift Cable and Housing Kit. Box’s marketing people put up some snazzy graphs showing how muck slickerier their cable housing is versus The Other Leading Brand. So… fine. In for a penny, in for a pound. I spent the $25 on a dedicated parts kit that gives me everything I need for how I intend to build this bike. You’ll see why I put that in italics further down the page.
Now that we’ve established the parts in order of assembly above, your first job to install your shifter assembly is to bolt that shifter loosely onto your handlebars. It goes on the right hand side unless you fancy yourself some kind of rebel and want to put it on the left. Upside down and backwards. Either side, at this point the shifter and its bare cable should be just barely be able to hold its position on the bars. Not so tight it will leave a mark if you move it around.
Whats a Ferrule?
Its a metal or plastic finishing sleeve that covers the end of your bare, cut shifter cable housing.
Above: The little whatsit sitting next to the bare cable is a ferrule, which I then stuff onto the end of the shifter cable housing. The fit will be snug but easy to make just by hand. No tools necessary. We are not going to attach the ferrule on the other side just yet.
Once we have fit the ferrule onto the end of the cable housing, we want to run the wire coming out of the shifter thru the housing. All the way through. The shifter cable will be longer than the shifter housing and we want it that way. Snug up the cable to the just-snug-on-the-handlebars shifter.
Now that we have the cable-and-housing hanging loose and on the ground, we want to run it back to the derailleur along the bike in the path its going to take when its finally installed. There are a variety of ways you can do this, but perhaps the easiest is to use cheap, reusable velcro OneWrap cable ties. I love these things, and they are perfect for this job as they are reusable, easy on/easy off and not permanent – unless you want them to be at which point they seem to last forever on a bike.
When running the cable back to the derailleur for this fitment exercise, leave slack up front coming out of the shifter so the cable is never tugged upon no matter what position the handlebars are turned to.
You should be able to figure out the path the shifter cable is supposed to take as there will be braze-on cable guides along the frame dictating the appropriate path. Most modern frames will have what looks like a little altar that you lay the cable across. Under the altar there is a slot made to run a little clip or a zip tie through to … strap the cable down… er… onto the altar (I should have sounded this out in my head first before coming up with that name).
I am bringing up this ‘altar’ and ‘modern frame’ business because my frame, designed in the previous century, is a product of an era when such things didn’t exist. So I had to improvise. But, I digress. We’ll get to the improvisation part last. For now I want you to see what it is that most likely you will be looking at on your own frame.
So you have followed the path laid out by your frame’s braze-ons to route your cable, and strapped it down temporarily with wire ties or similar. What you have now is a cable and guide assembly that is hanging out past your derailleur and is way too long for it. Its time to cut the cable to size.
Top Tip: Don't screw this up. Its better to cut a little too long than it is to cut too short. You can cut again if its too long. Too short... not so much.
Hold the cable with your hand such that it loops up and goes directly into the socket on the derailleur that is meant to accept it. You want the cable to go in straight, but not have so much extra in the loop it will catch on something – when you are whizzing down a hill a branch could tear that cable clean off, or worse.
Find a way to mark the spot you’ve chosen. Do not cut!
Why? Because the cable is still inside the housing. After marking the cable, you need to get some slack up front at the shifter and pull that cable entirely out of the housing. I know you only really need to pull it back several inches, but lets not guess wrong and screw up. Another 10 seconds of effort and the cable is safely, completely removed.
NOW you can take your cable cutters and, with one quick authoritative snip, cut the cable housing to size. Run the cable back thru the now-snipped housing. And here we are:
Now that the cable has been threaded back thru the housing and pulled gently taut, we fit the second finishing ferrule over the bare wire, and snug it down onto the end of our cable housing.
Next, pull the wire through the receiving socket on the derailleur and gently pull the cable housing assembly into that socket so the cable is snug inside of it. You aren’t trying to clamp anything down at this point so I am using words like ‘gentle’ on purpose.
Turn all of your ‘provisional’ and ‘temporary’ cable mounting into permanent mounts. If you do it right, ‘permanent’ is a misnomer as all you will have to do is cut the zip ties to free your cabling up again. But for our next step, we want everything in place as it is going to be as a final assembly. Try and get your positioned shifter about right on the handlebars. This will be one place where having a little extra slack in the fitment will help you later on down the road.
At this point I’m going to jump from written description to video. We’ve covered the installation of a new cable and a new cable housing. From here I can let the Box Components installation video do all the heavy lifting for final cable attachment, chain sizing, chain installation and finally derailleur adjustment. These instructions work great for the entire rest of the process, and not just for a Box Components drivetrain. Remember if something confuses you, you can always hit pause, drag back the cursor and play a step over again until you understand it.
Some quick notes on the video above:
When I first saw the instructions on derailleur adjustment in this video, I was skeptical. I was very familiar with the method shown in the excellent – and gold standard – Park Tool video below. However, what Box is describing above is a lot simpler than the method Park lays out… and it is after all the manufacturer’s official installation instructions. So I followed the instructions and was entirely surprised they worked perfectly.
The chain sizing method shown is different than many other instructions on chain length. Nonetheless it is absolutely correct for a 1x (single front chainring) drivetrain. Many builders get this wrong in part because there is so much misinformation on how to size a chain; particularly on a 1x system.
The key is to only slightly tension the rear derailleur cage. That ensures you have a taut chain, but also that there is much chain on your bike as your derailleur cage can possibly wrap. Make it any longer and it will sag and skip. Any shorter and you have shortchanged yourself when moving up to your biggest, lowest gear.
If you have followed through step by step on the video above, you have now installed and adjusted your your drivetrain. However, if shifting isn’t perfect, here are a couple of alternatives.
A Different Example
I recently installed a low cost Microshift Advent system on my Mongoose Envoy. The Microshift install video shows an entirely different derailleur adjustment procedure. And since the Box video worked so well when I first used it (on 2Fat), I decided to follow the Microshift directions to see what happened. It worked. This video has a slower pace and gives a much better look at some of the components and operations common to all 1x drivetrains (like the limit screws). However, I would not follow their directions on cutting/sizing the chain, as the method shown in the Box video addresses the real issue that has to be addressed (chain cannot be too long, so you make it as long as possible).
The Park Tool ‘Gold Standard’ Tutorial
This is the method I have used for years. It takes the most time, but it always works, and if you do nothing else, just watch it and learn all about how your derailleur’s adjustors interact. The methods above worked great, but they may not translate to your derailleur. If so, do it the long way with these detailed adjustment instructions. Since this is not an installation video it concerns itself solely with adjusting a derailleur in a completely installed drivetrain. This video is also the best in terms of helpful visual instruction of common component parts.
Unique Weirdness Worth Mentioning
My chosen frame comes from a bygone era. In that era, cable routing was done differently. First of all, those handy little zip-tie altars hadn’t been conceived yet. Instead on this frame we have circular braze-ons that require the cable to be routed inside of them. Want to re-route the rear brake cable? You have to disassemble the brakes to make that happen. Which was a pain back then, but more so now that we have hydraulic brakes that you don’t just take apart unless you feel like bleeding the system all over again.
It gets worse with the shift cables. Here again on this vintage frame we have the fixed cups meant to accept a cable end… but back in the day, cable housings were nowhere near as well-engineered (and slick) as they are today. So you see a frame designed to only use a minimal amount of cable housing wherever there is a bend, and then run all straight lengths of shifter or brake cable bare and out in the open air.
Well its not 1999 any more. In 2022 we have some pretty slick cable housings, and in fact my Box 1 shifter kit’s main purpose in life is to provide super slick performance with resistance so light the Box Components marketing department went crazy making sure you know all about it. On top of that, the brake cable runs meant for wired cable aren’t going to get any since we are using hydraulic hose instead.
Luckily there are inexpensive little doodads made that let you convert – more or less – these old school fittings to accept hose. Here they are installed, prior to cable and hose installation.
And below, here is how they are used. Not ideal, but a necessary evil unless I wanted to compromise performance for a vintage look on the shifter cable (which I didn’t) You can find these little parts (listed as ‘cable guides’) on the parts list in the Planning post.
And you will not need to use them at all if you are building your bike with a frame manufactured in the modern era.
Figure Out Placement and Install The Speed Sensor
I’ll make no bones about it: This item was very time consuming And there’s no reason it should have been. In the end I used almost exactly the same approach as I have taken with all of my other bikes, and the final solution looks like something I could have knocked out in a half hour. Sometimes when you are building a bike these things just happen. I only bring this up because I want to emphasize that if something similar occurs in your build… don’t get frustrated or upset about it. Just stick to it – or maybe walk away for the afternoon and come back tomorrow, fresh-faced. It’ll work out.
Like this one did. Here it is fully installed and wired up:
At left, you can see an overview of the entire sensor assembly including the magnet on the wheel, attached to the spoke. Please note this is not the Bafang magnet that came with the sensor kit. The Cateye sensor magnets you can buy from Amazon are lighter weight, and at least as strong if not more so.
As you can see in the photos above, the sensor is not sitting directly on the stay. Its sort of strapped to something. That something is a marine cable crimp. A couple of them are pictured below, and while they are not quite the same as the one I used on this project, the picture gives you an excellent idea of what they look like. I buy them at my local hardware store, but you can find them on Amazon too.
I have used crimps like this for most of my BBSHD builds. They are square-ish enough and rounded enough that they can easily be mounted either on a round surface or as here: a square one. They have rounded edges that mimic a rounded chainstay, which the Bafang sensor mount is curved to and designed for. And of course being a hunk of hollow aluminum, they are both strong and light. Below is perhaps my first use of a cable crimp (I was still using the Bafang magnet back then. This photo was taken in 2018).
In both cases as shown above, the cable crimp was used to move the sensor inward, closer to the spokes. If I hadn’t done that on either of these bike builds, the sensor would be nowhere near close enough to that magnet to register.
Also above is a close look at all the parts that make up the speed sensor. The silver screw goes into the back side of the magnet to glom it onto a spoke. The black screw is a set screw. The actual sensor end is a sliding arm that you can move inward or outward to help you come up with a fitment that works on your bike. This set screw anchors the parts once you’ve decided what position they need to be in. You can also see the two slots on the sensor base that you will thread a couple of zip ties thru to do your final anchoring. On the other side of those slots is an adhesive-backed curved surface that we’ll use as described below.
Lets go step by step on how this mounting is accomplished:
Figure out placement before sticking anything onto anything else. Your speed sensor will need to pass within about 1/4″ of the magnet (see the installed pic above – the middle of the three. That is how close you want to get). You can get away with a little more separation if you use the stronger Cateye magnet seen in this project. But don’t push it if you can at all help it.
Lay down a bit of 3M 2229 mastic rubber tape directly onto the chainstay. Just big enough for the crimp to smoosh into, which is what you will do next. This will provide a vibration free base for the crimp, as well as protect the paint on your frame.
Wrap the crimp with your paint-matched silicone tape. You can see in both pics above I used white. I actually have some gray now that I will use if I ever have to remove and replace this working mount (if it ain’t broke…). Between the tightly wound tape and the sticky, thick mastic, you have pretty much locked that crimp onto your frame.
Attach the speed sensor’s curved base to the curved corner of the crimp. This is where the shape of the boat crimp really shines as it mates the sensor perfectly to what is now a solid mount. The speed sensor has an adhesive base. Peel off the protective film and carefully stick the sensor onto the crimp. It should now stay put, but that sticky base cannot be relied on for long. Which is why our next step is to…
Zip tie the sensor to the mount and chainstay. For the Apostate, you can see I used grey zip ties to make as close of a color match to the bare alloy as possible. For the white bike above (that is the Stormtrooper in case you were wondering) I used translucent white zip ties. Once those zip ties are on, you have a rock solid mount whose only weakness is the plastic of the sensor. Be careful when you remove a wheel (on some bikes its smart to deflate the tire. You’ll know after the first try at taking the wheel off).
Connect Display and Speed Sensor
Coming out of your motor is a plug with a captured knurl-nut on it. That is your speed sensor cable. It has a flat side on its otherwise circular surface that matches up to the speed sensor. Plug it in and thread that knurl nut onto the threaded sensor, so the connection is locked together nice and tight.
Attach The Battery
Ordinarily I would not be placing the battery in the bike in its final position at this point. I’d usually put it on a table next to the bike stand; perhaps connected by an extension cable for convenience. This bike was different as I expected the battery to be a permanent fixture on the bike. I needed to be able to see the wiring challenges ahead of me: all of that wiring was going to have to live in plain sight. Cable management was not just something cosmetic I could tidy up later when I felt like it on this build.
As noted earlier, I found – via a V1.0 pack I already owned – the Luna Wolf pack was a perfect fit for this frame. I had a spare V2.0 magnet mount I wasn’t using, and that is what you see in my early fitment pictures with the bare frame. Here’s a closeup of that magnet mount.
Its a really well-thought-out product, what with its variety of mount holes and lonnnnng magnet engagement. On a frame with a big triangle you won’t be moving that pack without really wanting to, which is a good thing. On the Apostate, fitting it in the space available was tough, but once that pack clomps onto that magnet it really is best to not try to move it at all (and yes, it did eat one of my fingers once when I wasn’t careful).
To be brief, I bolted the magnet mount as centered as I could in between the two bottle bosses on the frame. The idea was, the attachment is so strong I did not want to create a situation where the battery being pulled up bends a long extension of magnet mount. These two pieces really, really do not want to separate and damaging the frame or the mount is a real possibility (my bottle bosses are drilled steel inserts into the alloy frame… 1999 technology).
As with some other elements of this build, this mounting issue was unique to this specific frame. Your experience is much more likely to be simpler and less drama-filled. This magnet mount is not problematic on modern frame construction.
I wanted this puppy pushed as far forward as possible. For starters, once this pack is on its on. Its not moving and I need to be able to connect and disconnect my cables to and from this otherwise wireless battery pack (a unique feature of the Luna Wolf – you make your own cables and plug them into the battery using built-in XT60 and XT90 receptacles).
Speaking of which, when building an ebike you are going to need to be making a cable or two. This is a great time to introduce you to a complete tutorial on the subject:
Since I didn’t do the wires on Day Two, we’ll save that discussion for Day 3. Suffice it to say as Day 2 wound down, I just made a test connection to the motor from the battery with a short Anderson-to-XT90 adapter (BBSHDs from the factory have a long battery lead terminated with Anderson powerpole connectors).
Test Motor Functionality
Its getting late, and I’m starting to get sick of looking at this bike. I need to knock off for the day. But before I close up shop I want to just test the motor to make sure it works. Otherwise I’ll be tossing and turning in bed, wondering if I got it all right. With the speed sensor and battery connected, all I need to do to make a functioning motor is to
Connect the Display
Remember how early in the day we put the display on the bars, and left the connection wire dangling? Its got a green HIGO female plug on it and the only place for that to go is the green male HIGO plug on the wire harness that we also left dangling nearby. HIGO plugs have little arrows on each side that you line up (also there are pins on the inside you need to see to double-check you have it right). Push them together once you have them lined up. These waterproof connectors will often come together with a little, audible pop.
Connect The Throttle
When we put the display on the bars, we also put the throttle on. Now its time to reach for the female yellow plug on it, and mate it to the male yellow one on the wiring harness which is the only possible match. Same deal here: Match up the arrows, and double-check by also visually watching the inside pin on the male side line up with its matching slot on the female side.
Turn On The Display
This is it. Moment Of Truth time. At this point, if you hit the On switch the display should light up (naturally you need to have at least some juice in the battery 😀 ).
When I did it for this bike, it worked! Now what do I do? Well the bike is up in a stand, so its safe to give it a little throttle… and the wheel spins around! Yay throttle works! What about pedal assist? Click down to the minimum level of assist (“1”). Grab the wheel to stop it from spinning (since we haven’t put the brakes on yet) and now… rotate the pedals. If the motor fires up and spins the wheel again, our pedal assist sensor works! Look at the speedometer display. Is it registering some kind of speed value? If so, the speed sensor is working. Look at the back end of that sensor. There’s a little red light you probably didn’t notice before. Is it lit up? Hooray. So far so good.
And with that, its time to call it a day.
Final Day 2 Note:
You may have noticed the chain is not installed in the end-of-day picture above. On the actual build day, chain installation and derailleur adjustment was held over to the start of Day 3. I spent so much time fighting with unusual issues getting the speed sensor positioned I lost a lot of time. By the time the photo above was taken it was evening. I was done looking at this thing for the day. A less fiddly build (i.e. almost all of them) would have allowed for chain attachment on Day 2.