You know dashcams create a record of evidence. Surprisingly, they are also visible to nearby drivers, and become a deterrent just by being in plain sight.
I have been using inexpensive action cameras (i.e. GoPro clones) for years as dashcams on my urban commute and cargo ebikes. Going DIY, I get much higher video quality and spend a lot less money. Once you figure out how to set them up, its an easy process.
I started doing this after I was run down (a T-bone SMIDSY) by a negligent driver in 2017. The police report worked hard to blame the victim (me) for traveling at low speed (about 15 mph in a 40 zone), with three headlights on, in the designated on-road bike lane. I even made eye contact with the driver while she stopped before pulling out and into me. I found out the hard way the driver was looking through me, not at me.
At least the police report conceded the driver was the cause of the accident – and tried to take it back a bit by stating that the safe speed for a bicycle “may have been 3 mph”. Yes, thats right… three.
Unfortunately, experienced urban cyclists will recognize the problem. Motorists often get every benefit of the doubt when they run down a cyclist, regardless of the consequences of the motorist’s inattention. I was carted off in an ambulance.
Cyclists Need an Irrefutable Witness
Over the years, I have learned a few things about what kind of camera is well suited to this job, how to best install it, and how to configure it so it is as easy as possible to use on a routine basis. During a recent online discussion on the subject, it occurred to me this would be a good topic to lay out for people all in one piece.
Lets make a centralized parts list right off the bat, so its easy to come back to. We'll get into what each item is and why it is on the list further on:
As alluded to in the lede above, having visible cameras does more than just preserve an evidence record (I tell people who ask about them – only half jokingly – they are there to tell the police who killed me).
Something I have experienced has been echoed to me informally by other cyclists: People treat them differently when the camera is there, blinking its little red “I’m on” light. Drivers seem to behave with a bit more civility. Is this a scientific observation? Nope. Is it a universal benefit? Nope. But it does look as if, when people know that Little Brother is watching, they are less inclined to brush you back or run you off the road.
Once I realized my own perception of that phenomenon was not unique, I decided to supplement front cameras with a second, rear-facing one. Yes I want to get video of an oncoming vehicle that may do a bad thing. But even more so, I want that driver to maybe see the camera and … sober up a little?
Worth mentioning: Cameras like this have been used for years by motorcyclists, and I think motorists have grown somewhat used to them as a result. I have yet to see a volatile reaction by anyone getting mad I am recording them as they go by.
However, I do respect others’ privacy, and I will not be showing any stills taken from my cameras that show clear license plate views (which is the high standard we are going for here).
What About Turnkey Products?
Turnkey solutions exist for cyclists right now. Perhaps the original is the Cycliq Fly. One look at the price for front and rear cameras may give you pause. But if protection is afforded, price is secondary.
Instead, when evaluating them dig a little deeper at the camera resolution. The front camera provides a best resolution of 4K @ 24 fps, with 6-axis electronic image stabilization. That is pretty good but – in 2023 – unremarkable. The rear Fly6 on the other hand gives you a 135-degree view at a resolution of either FHD (1080p at 30fps) or HD (720p at 60fps). Their rear camera provides no mechanical or electronic image stabilization.
The Cycliq product also incorporates an app, and each version also incorporates a light.
Garmin makes a bike camera system as well. Its rear-facing Varia is a combination of rear light, camera and actual radar. The radar senses an approaching auto and warns you of its approach. Rider discussions I have seen report the radar really works. Insofar as the camera is concerned, its best resolution is 1080P @ 30 fps. There is no front camera option.
Bottom line: A turnkey solution for both front and rear is going to cost rather a lot of money. It may or may not provide a video solution that allows resolution and stability that will capture a legible license plate. I consider that license plate essential as it may belong to a vehicle that left the scene long before you are carted off in an ambulance.
In my own personal experience, I have tested the video resolutions and frame rates described above on cameras and consider them failures in the license plate reading game. They will be fine for capturing what happened, but if the car leaves the scene, law enforcement officials won’t be able to identify the vehicle from the plate number.
What About DIY?
It turns out ‘generic’ action cameras have all the features you need to make a dashcam. You just have to know how to set it up, which is not difficult. They will give you a highly detailed, electronically-stabilized screen resolution (you cannot take stabilization in all resolutions for granted and have to carefully review camera specs to confirm this).
I have bought a number of cameras over the years. Some have been expensive (GoPro), some have been really cheap (low end Chinese GoPro clones) and some not so cheap. I will skip any further mention of that learning experience and just jump right to the one that works best for me now – in 2023.
The Akaso V50X Action Camera
In 2023 as I write this, this model has been around for awhile. I bought my first one in early 2021. So it has a feature set that is not state-of-the-art.
In 2023 as I write this, this model has been around for awhile. That means it is not a premium priced product. I bought my most recent two on sale for US$79.99 each. MSRP is US$99.99.
The camera uses a native 4k resolution with a native 30fps frame rate. There are other rates available going up to 60 fps, but in side-by-side testing, the 4k/30fps with image stabilization enabled gives the best license plate readings. Note I said ‘native’ above. That means there is no on-board interpolation to up- or down-rate the image. Since ‘interpolation’ means ‘adjustment’ and ‘approximation’, native processing modes should give the camera’s cleanest end result.
No proprietary software is needed to play or process the video. I use the movie software included with Microsoft Windows 10 to view and edit the files.
Electronic Image Stabilization (EIS) differs in effectiveness from brand to brand. EIS on the V50X is very effective. I almost can’t see how it could work better. I have tested it on potholes and curbs and the video remains steady.
Settings are available to loop record, which is a critical feature for a dashcam application. The camera records in short time-loop intervals (shorter is better… we’ll discuss why later), then starts another file. When the SD Card storage fills up, it records over the oldest files, so you never have to flush it clean when it fills up.
Settings are available to turn the camera on as soon as it receives power. A driving mode makes camera startup and recording automatic, although I prefer not to use it.
Out of the box, the V50x comes with a zillion accessories. Way more than you will ever use. The one accessory that is critical is included: the waterproof scuba box (not needed for waterproofing… we’ll get into that later). You can buy a second box cheap on Amazon to share a camera across multiple bikes.
Its got a slightly bigger battery than other models in the Akaso line (which I also own). We’ll discuss a setup that bypasses the battery later.
Having had a V50x in service since 2021, and other Akaso cameras since before then, I have found the brand produces a reliable product.
A shorter version of the above is: “the V50x is cheap, durable and does everything you need for a bicycle dashcam.“
SanDisk Extreme Pro Micro SD Card
You need this for the camera to store its video files. No camera comes with them and they have to be purchased separately. With a 200 mbps write speed, this is the fastest card you can get your hands on right now. You need big write speed to support the 4k/30fps mode on the camera. And since Micro SD cards are cheap, a relatively gigantic 128GB card is only US$20.
According to the instruction manual, the V50x camera only officially supports 64GB cards, but the manual also says some 128GB cards will work. This one works. I use them due to the fast write speed, not the storage size.
The Front Mount
I’ve tried a few mounts and, once I settled on this one, have stuck with it for years across several bikes. It is all alloy, no plastic, and mounts rock solid on the bars. Over time it does not loosen up, and keeps the camera in place regardless of bumps and bonks as I go down the road.
It does rotate on its horizontal axis by design, but there is a strong detent in place so it can’t happen accidentally. This rotation lets you put the same mount at different positions on a swept-back bar and it still points straight forward.
The Rear Mount
I have only recently started doing rear cameras and this mount was exactly what I needed to make it happen. It is all aluminum with stainless bolts, and mounts solidly to the saddle rails. It doesn’t move over time. Its easy to mount the camera to its GoPro-compatible mount.
This mount does make it necessary to mount the camera upside-down, but all of the video-editing software I have ever used – and I always use something simple and free with minimal features – allows you to easily flip the video right side up. The time stamp onscreen will be upside down but we aren’t trying to be Cecil B. DeMille here … its just a dashcam video.
The (Optional) Power Pack
There are a few ways to power your DIY dashcam solution. One way is to just use the in-camera battery. Another is to run a little USB cable from the camera to your ebike display’s USB port. That will give you a constant power supply that never runs out. If your display does not have a USB port available, the next best step is to fudge it and use a USB power bank. I have found it is much more convenient to use a big power bank and charge it, say, once weekly, than it is to use the in-camera battery that is going to need recharging after every single ride. I’m including links to two different – and big – power banks.
I do not use power banks this big to run just my camera. These banks have three USB outlets. I use all three – two to power my LED COB light banks and one to power one of my two cameras. I have a USB display powering the other. So for a more normal bike, one such power bank could power two cameras no problem for a week of long, daily commutes. A much smaller power bank would probably be fine, too; especially if handlebar bag space is at a premium.
I am linking to one Anker power pack that is a top quality item and priced accordingly. I’m also linking to one much cheaper and – on paper at least – is just as capable and 1/3 the price. I can’t be sure if it is as reliable as the Anker but for twenty bucks versus almost seventy… I figured it was worth a shot. I have only been using it for a few weeks so far.
Misc USB Cables
There are a half-dozen different ways to wire these things up. If you are doing a direct wire to a power bank or display on a rear camera, a long-ish USB cable with a right-angle plug at the camera side is a good choice. If doing a front camera mounted to the bars and tied to the USB plug on your handlebar display, you can get away with using the short freebie cable that comes with the camera. If things are lined up just wrong on your display, you may want to use a short 45-degree USB extension. We’ll go over a few variations …
… when we tackle camera installation and configuration in the next installment. 🙂
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.
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.