Big Fat Dummy: Make It An Ebike

What is necessary to transform a Surly Big Fat Dummy into an electric bicycle? I thought my BFD series was finished until I realized I left this part out.

The Surly BFD Project Menu
Prologue
Episode 1: 138L (each) Panniers… Seriously?!
Episode 2: Big Fat Dumb Wideloaders
Episode 3: Kickstand Kaos
Episode 4: Add a Flight Deck. And a Hangar.
Episode 5: Leftovers
Episode 6: Electrification (You Are Here)

Oops?

On the surface, it seems I left a hole in my description of my Surly Big Fat Dummy build. I omitted this episode and thought I was done. In my defense, there are zillions of BBSHD installation tutorials out there, and I have described a BBSHD install myself – on a cargo bike no less – right here in this blog.

However, I haven’t done a writeup geared to THIS bike. Since this blog is dedicated to answering questions that I see asked a lot (and I have seen this one more than a few times), I’ll do something a little more focused on the BFD.

Bear in mind the bike has been in near-daily use for months already. I had to dig thru my archives for pics rather than taking them as I went along. So illustrationwise, there’s not much to see. On the flip side of that, there doesn’t need to be as the Big Fat Dummy is an easy (easy!) build.

Since I have covered this ground elsewhere, I’ll be leaving generic details out, and providing links to related content more so than I will be doing in depth step-by-step instructions.

Get On With It Already!

Yeah, yeah sure … here we go.

Step 1: Buy What You Need

This can be very simple or very involved. Especially if you are a first-timer and don’t know what you need and maybe not even what you want. In my opinion the best motor for the job is a Bafang BBSHD. I typically buy my motors from Luna Cycle, and here is their page for their kit. They may or may not be selling a battery along with that kit. I am using a different source for the pack as you will see further below.

If you buy the kit, you don’t have to worry about buying individual bits, with the exception of needing a speed sensor cable extension, and a proper chainring.

But, lets go over the individual bits. Myself personally, I just buy the bare motor from Luna, and add the parts I need to complete the installation. This lets me use exactly what I want, which is not quite possible if buying the packaged kit. Here are all my parts:

  • Bare Motor:
    Purchased from Luna Cycle here. The Surly Big Fat Dummy requires the 100mm sized motor (It will be a perfect fit). if its available you can buy the optional spacer and mounting kit on that page. At the moment, Luna is not selling the 100mm mounting kit – the only difference is some M6 bolts and spacers… you can source that yourself to the correct size if needed. Or just buy the needed parts separately. Go ahead and accept the 46T chainring (aka ‘The Disk of Death’) as its a free throwaway item you would (should) never use.
    Secondary Source: California Ebike is a reliable alternative and one of my go-to sellers for parts, but their motors cost an additional $100 or so. Here is their BBSHD motor page. Note that Cali Ebike offers users who may need it service after sale. Luna is a better choice for the confident do-it-yourselfer who can diagnose and fix most issues themselves, and save a hundred bucks by taking on that risk.
  • Motor Mounting Parts:
    • Triangle Mounting Plate:
      This is what puts the bite on your bottom bracket to firmly affix the motor. You can buy these plates at Luna Cycle, BafangUSA Direct or Amazon.
    • M6 bolts, washers, spacers:
      Needed to affix the Triangle Mounting Plate, these are commonly available. If you work on bikes you probably already have them in the garage. If you buy a mounting kit they may have them but in all cases I recommend you do not use them and instead go out and buy stainless hardware.
    • Lockrings:
      I use two inner rings stacked atop one another. If you like, you can buy the more conventional inner and the aesthetically-pleasing outer. More on the reasoning behind the choices below. Buy the rings at Luna Cycle, Bafang USA Direct or Amazon.
  • Speed Sensor & Cable Extension:
    You will need the sensor (which integrates a length of cable to plug into the motor), the sensor magnet and an extension thanks to the Surly Big Fat Dummy’s long tail. I have seen builders route the sensor to the front fork but by necessity this puts the sensor inside of the tire rim’s width, which makes for issues taking that tire off. Put it on the back where it belongs and forget about it. I described the sensor in a fair bit of detail here. Don’t mess with multiple magnets unless you feel a need to experiment, but I do provide a link to what I think is a lighter weight, superior magnet that you may want to substitute for the Bafang wheel weight that comes with their sensor. The speed sensors themselves are available in a wide variety of places, cheapest at Luna but also at California Ebike and many other sources. You can get the speed sensor extension anywhere you can find the speed sensor. California Ebike or Bafang USA Direct or many other sources, including Amazon with Prime Delivery. Notice all of the options I linked are different lengths. Measure the gap you have when you are routing your cabling and decide which one you want, accordingly.
  • A Proper Chainring:
    I am going to skip most of the detail here and refer you to this blog post on BBSHD chainrings. It was written with the Mongoose Envoy build in mind but the Surly Big Fat Dummy has essentially an identical set of problems and solutions. I will say this: For a combination of mostly street with some mild trail use I settled on the 46T Lekkie Bling Ring, which biases chain line towards the bottom half of the 11 speed cluster. This is the ring that has the most miles on my bike and its the best all-rounder. At the moment I am set up mostly for trails, though, and as such I am running the Luna Eclipse 42T which biases chainline heavily toward the inner half of the rear cluster, giving me the best possible access to the inner cogs.
UPDATE: But I did that anyway.  I put on a very small Lekkie 32T ring on the front in anticipation of some very serious trail rides in the Lower Sierras.  You can go smaller than a 32T but this ring - which is a little smaller than the secondary housing of the motor - is regarded as a very good sweet spot.  A 28T is so small it can contact the motor housing, which is bad.  The 32T in conjunction with the biggest rear gears on my rear cluster (46T) can climb anything possible to climb at all on two wheels, while leaving the motor in a good place, power-wise.

Note with a BBSHD, the stock My Other Brother Darryl rims and the stock Edna tires, you may not be fully able to use all cogs simply because chainline will not be acceptable for a 1x drivetrain pumping out 1000 to 1750w. You can do it, but the chainring teeth and maybe the chain will not last very long if you run at either extreme – say… the smallest cog and the Luna chainring. It all depends on your final component choices, so just be aware of the issue and check for it to make sure you don’t have any issues that you need to compensate for when riding.

Two of the pics below show a 130 BCD adapter which really biases chainline to the lower cogs, and is best for the street. Both of these use 48T, 130 BCD chainrings. Even though most of my mileage on this bike is with the 46T Lekkie ring, it doesn’t appear as if I ever took a picture of the bike with the thing installed.

  • Crankarms:
    In two of the pictures above you can see I used Lekkie Buzz Bars, and with their forged construction and left offset to correct the misalignment under your saddle that will happen with standard crankarms. Luna Cycle sells a less-expensive clone worth looking at if you can’t handle the price of the Lekkies. As a last resort you can also use the standard Bafang crankarms that are cheap and cheaply made, but good enough for many riders. Make sure you buy BBSHD-specific arms or they will not have the left offset.
  • Display:
    I have used many displays and hands down, at the present time the Bafang/Luna 860C is the best out there. It is fully visible in blinding sunlight and can be set to display both real time amp output as well as real time wattage. The Luna version reads battery voltage level accurately up to 60v, meaning it works with 52v batteries. Bafang versions of the 860C may not. There are many other options for a display including a low-visibility-but-clean/low profile EggRider v2. For my money the 860C is worth waiting for if its temporarily out of stock, and its now my go-to for bikes I build.
  • Throttle:
    I like the basic el cheapo Bafang universal thumb throttle. Its an easy fit and unobtrusive. If you follow my lead on BBSHD settings for it, its annoyingly short throw will still be well controllable and allow for fine adjustments while riding. Buy it at Luna, California Ebike or Bafang USA Direct.
  • Main Bus Cable:
    You have options here. the main bus cable is available in short and long lengths, and there are also extensions available. However nothing fancy is required on the Surly Big Fat Dummy. You can buy this standard one from Luna or many, many other sources. If you opt to use Magura MT5e brakes, California Ebike has a specially modified harness to plug in the red Higo/Julet cutoff connectors the MT5e uses. I am using this bus cable and MT5e’s, myself. NOTE: If you opt to keep the SRAM hydraulic brakes you will not have brake-actuated motor cutoffs. This is no big deal. They’re nice but the stock brakes can overpower the motor in a pinch. If you like, you can invest in some hydraulic cutoff conversions that involve gluing on a magnet to your levers and strapping on some wires. the alternative is a brake upgrade (not a bad thing, but not cheap, either).
  • Installation tool(s):
    Using one of the many Bafang-inspired toy wrenches to install a BBSHD is a cruel joke on the inexperienced. You have to use a proper torque wrench and special socket to do the job right, where the motor doesn’t move. I’ll leave the torque wrench choice to you (I use a Wera B2). The socket you need for the inner ring is often out of stock. Buy it here at Luna Cycle or hunt around… its available elsewhere if you look. The tool for the outer ring can either be hand-tightened – if you must – with a stainless steel version of the cheesy Bafang wrench. I bought this one on Amazon so I know it fits. But it is absolutely a sucky solution. Better is to use a 16-notch bottom bracket tool that you can fit onto a torque wrench and do a proper job of applying the manufacturer’s torque spec, written right on that outer ring. Note if you use two inner rings stacked on top of one another like I do you do not need the special outer ring tool.
  • The Battery:
    There are a bunch of different ways you can play this. Among others you can plant one on the bike on the framework just behind the seatpost. At present mine is in the triangle in a bag. My size Medium frame can just barely hold this 21ah, 52v battery from Bicycle Motorworks. ‘Barely’ means after I have added some padding. I also keep the battery in a quick-detach bag inside the triangle. I described the quick-release setup with pics in detail here.

    I’d like to have more room for padding, so I am exploring a shift to that framework as an alternative. We’ll see as its a big change.

Step 2: Remove Stuff

OK so you have all of your parts for the motor… Time to take things off so you are ready to do the installation. Its a simple list: Remove the crankarms, bottom bracket and chainrings.

You’ll also want to pull off one of your handlebar grips in preparation for installing your throttle. Which one depends on how you want to set up the bars. You will also likely want to loosen up and shift around your brake levers and the remaining rear shifter so your throttle is butted up directly against your hand-grip, rather than the brake being there. this is a bridge you should cross when you come to it, disassembly-wise.

Initially I used a Luna Wolf Pack, as shown in this picture. Thats another option for your build.

Thats it. You’re ready to install your motor.

Step 3: Install The Motor

Here again I’m not going to get too deep into the specifics of motor installation. I’ve already covered it myself elsewhere for a similar bike, and God knows there are plenty of video and written tutorials out there on the interwebs. However I will note that the 100mm motor is a perfect fit on the Surly Big Fat Dummy, which requires no spacers of any kind. Just put it in like it belongs there and clamp it down tight.

About that clamping part, I will go into that a bit:

Lockrings

I mentioned above that I like to use two inner (gray) lockrings: I stack them atop one another in jam-nut fashion where each is tightened to 100 ft lbs. Thats quite a lot more than the Bafang specification for using just one inner lockring. I am going off of installation advice provided by Luna Cycle – not in their official installation video linked above. At one time there was a supplemental vid made in their shop that discussed their learning experiences assembling their shop bikes. It went hand in hand with the use of a big 1/2″ torque wrench to apply the necessary force, and that wrench in turn used a specially made Luna tool for the lockrings (that sadly is no longer available, although you can see them on the site still). The use of 100 ft lbs and some additional info on it is in the link to the tool above.

I have stuck to that 100 ft lb specification and it has never let me down. I have also added to it by using a second inner lock ring rather than the ‘beauty’ trim ring that is more typically used. The number of threads needed for another inner ring is about the same. You gain the benefit of a serious jam nut holding down the first ring. Also, something we are not doing here but you can see elsewhere: If you are building an AWD bike, the use of two rings lets you mount the front wheel’s PAS ring in between the two.

I do not use the outer trim / beauty ring at all.

Lastly on the subject of lockrings, here’s a technique to tell at a glance whether the rings are loosening or your motor is shifting (or about to): Make a registration line along the frame and the lockrings. If the line ever breaks apart, something is loosening. You can tell with a simple glance down as you are mounting the bike.

See the registration mark (aka the black Sharpie line)? Also note there are no spacers needed on the locking plate under the M6 bolt on the left. Perfect fit for a 100mm motor.

Next, I’ll make note of how I did the speed sensor installation, both with the factory SRAM brakes and my later MT5e upgrade.

Using the SRAM Brakes / No Helpers

Attaching a speed sensor on a Surly Big Fat Dummy is not as straightforward as it is on a typical bicycle. In addition to the added distance – addressed with an extension cable – there’s no place to put the thing! The frame is different enough that nothing appears to work – on first glance.

Keep looking! The SRAM brakes that come stock with the bike have a weird sort of tail hanging off the caliper, and this is a handy, if unusual, place to mount the speed sensor.

I first wrapped this tail with a length of 3M mastik tape to enlarge its diameter and give the sensor more to grab onto. Then I simply zip tied it on as if it were a chainstay, and aligned the magnet as usual. These pictures show a dusty bike as they were taken just before I uninstalled the sensor and upgraded the brakes to the Magura MT5e’s.

Using Other Brakes – And a Crutch

For the Maguras, there was no such luck as the calipers have no tails or anything else I could glom onto. So I had to add something: I used a simple small handlebar extension, and built up the frame to a proper larger diameter to mount it by wrapping the frame with gorilla tape, which I then faced with silicone tape to provide a grippy surface for the bar mount. Next, I used more zip ties (!) to clamp the new ‘frame tube’ to the upper part of the Big Fat Dummy’s … superstructure. Once this was done, I had a tube close enough to the spokes to re-mount the speed sensor as shown.

What About a Gear Sensor?

Good question. Read this.

Whats With The Heat sinks on the Motor?

I’m glad you asked. Here’s your answer :-).

What Else?

Well, a bunch I suppose if you were looking for a bolt-by-bolt conversion tutorial specific to this one bike. But really, between the other pages already on this site and the links I have given off-world up above, you’ve got everything here that you need to buy – and build – your own.

So have at it!

Big Fat Dummy: Leftovers

We hit the high points of the Surly Big Fat Dummy build. Lets wrap it up with a discussion of some odds and ends

The Surly BFD Project Menu
Prologue
Episode 1: 138L (each) Panniers… Seriously?!
Episode 2: Big Fat Dumb Wideloaders
Episode 3: Kickstand Kaos
Episode 4: Add a Flight Deck. And a Hangar.
Episode 5: Leftovers (you are here)
Episode 6: Electrification

Basket-Case Handlebars

One of the most notable features of this Big Fat Dummy are its handlebars with the integrated basket made of thick, hollow alloy tubing. At first glance, these are nothing more than EVO Brooklyn integrated-basket handlebars. Here’s a factory-stock picture of them.

Now lets take a look at the ones on my Surly Big Fat Dummy. Notice a difference?

Figure 1. Hint: Look at the grips

The grips give it away: I extended the handlebars so now they have a width of about 810mm. I am using ESI Extra Chunky 8.25″ grips to cover the extensions and give me an extra-long gripping area, suitable for multiple hand/seating positions (choke up and hammer it, sit up and cruise). Just like on a pair of Jones bars, the brakes can be reached from any position on the handgrip.

The grips give something else away: the bar extensions have a smaller diameter than the stock handlebars. At first I planned to use the extension you see in the pics below as an internal sleeve coupler between another bit of tubing, the same outside diameter as the handlebars. After seeing it in place and thinking this ‘coupler’ had potential on its own, I covered one side in a grip to see what it felt like. The two diameters worked for me and I decided to stop there.

I like the lesser diameter as a sort of change to the handhold. Good for longer rides where I want to vary my grip to reduce fatigue. The wide outer hold is better suited to comfy cruising anyway, so between that and the added thickness provided by the fat ESI grips: The lesser diameter section feels normal. The point of transition between the two diameters is also another form of handhold variation. It is just one more way to grip the bars differently on a long ride to change up what part of my hand is getting pressure.

What about the bar extensions themselves?

They are a bit of aluminum bar stock whose outside diameter is very near that of the inside diameter of the handlebars. Some fairly pricey stuff can be found at specialty hardware sites. I stumbled upon pre-cut bar stock with the right OD; already cut in the perfect length, so I didn’t even need to put a saw to it. (I did chamfer and bevel the inner and outer edges with the same tool I list in the Big Fat Wideloaders post). I bought two of these and that part of the job was done.

Specifically, the material is 6061-T6 aluminum bar with a 0.625″ (5/8″) outside diameter, a 0.375″ inside diameter (0.125″ wall thickness). Each bit of tubing is 10″ long. On the off chance its a link that will live on (its live as of today, several months after my purchase), here is what I purchased.

How did I affix it inside the handlebars? A combination of things hold these extensions firmly in place:

  1. The inside diameter is a close fit but not a tight fit. I wrapped a single layer of silicone tape around the inner bar in two places with a gap of a few inches in between. Just enough to make it a seriously tight fit.
  2. I spread/glopped some JB Weld around the outside diameter of the inner bar, in between those silicone tape wraps, before insertion. That makes for a bit of a seal for the application of the JB Weld and ensures during insertion it builds up into enough to fill the gap between both bars.
  3. I inserted the bar fully and then used a 2-lb sledge to make sure it was for-sure seated inside the handlebar.
  4. Stretching/installing the ESI grips over the assembled, extended bars provides, in and of itself, a strong hold that prevents movement.

One last note: Even at an 810mm width and extended grip length, the ESI grips are just a skootch too long for this bar, considering the controls I have to mount on whats left of its straight portion. I turned that bug into a feature. The ESI grips are so substantial they are good as bumper pads. To supplement that, I tightly rolled up some white silicone tape (the same stuff I used in giving the bars a tight fit) and used that as a bar end plug. The roughly 3/4″ of overhang is now a substantial padded bumper, useful when I am leaning the bike up against something. You can see the bumper in Figure 2 below.

The Double Stem

Figure 2. Going up. The stems are angled up in this pic for an elevated bar orientation.

Wait… what? A double stem? What the hell is the thinking behind that?

So, here I am building out this Big Fat Dummy with these basket-case handlebars. I have used them before, on Frankenbike. On that bike, the bars could shift down if you were standing up, honking on the pedals and putting strong downward pressure on the bars. Knowing this can happen, how can I get around it? Would using a higher quality MTB stem do it? Then I realized a)I had an uncut steerer on my Bluto fork and b)the handlebars have two mounting points in their design.

The idea was to use one or the other. But that long uncut steerer might just let me use both (spoiler alert: it does).

So, as usual I tripped and fell into a functional and eye-catching solution. Use varying spacers in between the two stems so they space apart exactly to fit the two mounting points. The lower 25.4 stem mount point needs a 31.8 spacer around the bar. Also, the easiest way to limit the variables in play is to use identical-model and -angle stems and simply vary their length. I used Funn Stryge stems in 60mm and 80mm.

In Figure 2 above I have angled both stems up, giving the most upright position possible. Later on, I flipped the stems to a down position to give more lean-over (clearly these bars have a significant rise built into them so seating position is still fairly upright).

Figure 3. Going Down. Both stems are mounted upside-down for a lower handhold. Just reverse the front plate so that part is right-side up.

In my final tinker with the stems, I changed their orientation once again: The lower stem is still pointing down, but the upper one is pointing up. This still keeps the bars oriented in the ‘down’ lean-over position, but the position of the upper stem moves further down the steering tube to achieve the same bar angle it had when it was matching the lower stem as seen in Figure 3.

Whats the point of doing that? It uses less steering tube. As you can see in the pics above, I am using 100% of the Bluto’s uncut tube. Making this flip and exposing more available steering tube enables a change to a Wren Inverted fat fork, which reportedly had a shorter uncut steerer…. with this change I would use 100% of the Wren tube, should I ever find another home for the Bluto.

UPDATE:
The Bluto did find a new home and the Wren is on the bike now... I compared them while I still had both in hand and both forks have identical steering tube lengths.

Reinvented Wheels

The Surly My Other Brother Darryl wheelset that comes with the Bliolet Big Fat Dummy is very good. It can take quite the beating. I certainly have never been able to throw either of them out of whack. However, I wanted summer and winter wheels, the ability to go tubeless, and have wheels as strong as possible. Additionally, the MYOBD wheels hold on to tire beads so tight it is effectively impossible to get at a tube to repair it on the side of the road. That had to change.

SIDEBAR: If the MYOBD rims are tubeless-compatible as claimed by Surly, mine certainly are not. The rims are pinned and not welded. And both of mine leaked at the pinned seam on the edge just under the bead – a place you can’t tape. I personally don’t see how they can be used tubeless unless you get lucky and those pinned rims are perfectly manufactured. Mine were, and are, great tubed wheels but they can’t be used tubeless even when its been done by professional LBS techs who know what they are doing. I failed. They failed. The rims don’t work tubeless.

With that said, lets focus on the wheel build. I settled on the following components:

DT Swiss 350 Big Ride hubs

The DT Swiss 350 Classic is just that. A reliable classic. In particular, the rear hub is acknowledged by DIY builders as extremely durable when paired with a high powered mid drive. Couple the ratchet engagement mechanism to the steel cassette body option that DT offers and you have the core components of a bulletproof drivetrain. DT even makes the 350 Hybrid hub that is reinforced still further for tandem and ebike applications. Sadly, its not available on the fat bike Big Ride variant. But a plain 350 with a steel body is still unstoppable. I know because I have used one on my 2Fat build for some time. The 2020 parts shortage made finding a front and rear hub an adventure – I got the rear in Poland and the front from the U.K. … But I got them.

Alloy on the left after 1500 miles. Zero miles and steel on the right… After 2 years it still looks that good.

Nextie Wild Dragon II Rims

This was a tough one. These are expensive hoops at over $300 each. However, they are also a known quantity as I own another set on the Stormtrooper (those wheels with their matte 3k finish are the header image for this blog). The standard version (not the Elite light weight) have a load capacity of 250 kg.

As far as I can tell, nothing else on the market can touch that load capability. Also, they have a center channel I know from experience makes ALL the difference between getting the tire off the rim on the side of the road, and not being able to do so (that would be the case with the MYOBD’s). Lastly, they are a nice compromise of 90mm, which I hoped would allow me to lose only the highest rear cog on my 11 spd cluster. Turns out that was a correct guess. Others who go 100mm lose the top two.

The Nexties check all the boxes. It boiled down to whether I was willing to spend the money. After some time hemming and hawwing, I surrendered and spent the big bucks.

<takei>”Ohhhhh Myyyy” </takei>

I did 3k matte finish last time. This time I upped the bling factor – just a bit – and went 12k matte. And holy cow are they ever gorgeous. They fit the bike perfectly with that deep dish construction making the fat tires the fattest fatties in Fatland. As it is, this beast of a bike already makes a serious visual statement. The wheels dial the message volume to 11.

With the above said, you might be under the impression that the look of these wheels contributed to my buying decision. I am outraged anyone could consider such a thing.

In addition to looking marvelous, they’re waterproof too!

Sunrace CSMX8 Wider Range Cluster

The original Surly-spec’d cluster is a Sunrace CSMS7 11-40T. Even though the Surly BFD is not sold as an ebike, that is the perfect 11 speed cluster for one. It is all-steel, bolted together into a single 1-piece unit and has steel spiders inside. As usual the heavier, cheaper steel component is the good one if you have an ‘e’ in front of ‘bike’. Finding an 11-42T version of that cluster would have been perfect… but alas thanks to the 2020 parts shortage, I couldn’t get my hands on one. I settled for the CSMX8, which is 11-42T and also uses steel cogs. Its in 3 pieces and uses alloy spiders. Not ideal on a mid drive, but its still a respectable bit of kit. Why did I want a wider range cassette? because I knew other Big Fat Dummy riders who went to wider rims and tires lose their two biggest cogs. Expecting this, I wanted the biggest cog I could still get to. So: wider range cluster.

As it turned out, the 90mm rims and 4.8″ Vee Snowshoe XLs only cost me one cog. So while I cannot use the 42T cog without rubbing, the 36T just under it is no problem. That means I only lost four teeth off of my former 40T inner cog, and I have a 10-speed instead of an 11. I’m fine with that.

Sapim Strong Spokes

Here is the one place I compromised. I wanted DT Champion 2.34 spokes. In the age of lockdown-induced bicycle parts shortages, that was just not happening. Nobody had enough spokes in the three lengths I needed … worldwide. Actually I did find stock in a bicycle shop in Germany but they refused to ship to me because of the then-severely-extended ship times of 10 weeks-plus. DT Swiss themselves said forget about it until at least 2021. Casting about, I talked to other strong players including Phil Wood. Every time, I struck out. Eventually I did find a small local bike shop in another US state who had Sapim Strong spokes and could cut them to the sizes I needed in-house. The 2.34 Champs would have been stronger, but the Sapim’s are plenty strong themselves. I don’t expect any issues.

Orange Seal Valves and Whisky Tape

Last but not least: The valves and the tape. Whisky tape is good stuff – a bit wider than most alternatives – and I was able to find a big roll, so I had plenty of extra socked away for my attempt at converting the MYOBD rims to tubeless (which as noted above… failed). I chose the Orange Seal 60mm valves because they have something a lot of valves do not: A metal bottom. Why? the metal bottom provides a hard surface that the valve gasket can firmly smoosh up against. There’s no way for the valve to pull thru. Its also less likely to spring a leak down the road when you manhandle the valve putting air into the tires. This last issue plagued my Stans valves on a different bike, until I replaced them with these.

You get everything but the kitchen sink in the bag with the Orange Seal valves, including a nice core-remover that screws onto the valve itself so it can’t get lost.

Phat Tubeless Tires

So… on this bike… tubeless is where its at! The Nextie rims coupled to Whisky tape seal right up. The Vee Snowshoe XL’s I put on (I have had them in the garage for a couple years and it was time to use them up) sealed to the rims so well I didn’t really need any sealant to finish the job. They held air for days as-is.

But of course I used sealant. And as I have mentioned in earlier posts, after discussion with the manufacturer and some great experience with it as a tube sealant, I used the recommended 16 oz(!) of FlatOut Sportsman Formula as my tubeless sealant. Application is easy via adding a presta adapter to the end of the integrated hose in the bottle lid. Once in the tire, they hold air for about… 5 (five!) weeks before its time to air up again.

And since I set these tires up, after a few months, I had the worst-case experience with respect to finding out whether FlatOut actually works to seal up tires.

Want to see a cyclist poop his pants? Punch a line of a half dozen of these in his back tire. Then tell him to hop off the saddle and go look…

Yeah thats right. So I go to Home Depot and load up on all sorts of crap. My Great Big Bags as well as my upper deck are pretty much full and I am chugging home. Suddenly I hear a tickticktick behind me and I know thats not good. I jump off, look down and OH.MY.GOD I see a row of about six roofing nails stuck deep in my back tire. As if thats not bad enough they are off to the side in the vicinity of the sidewall (the ticking was a nail head hitting the frame as the wheel revolved). Not thinking to save the nails for a future photo shoot, I pulled them out and cast them away. When doing that I saw the tire knobs pull away from the tire thanks to the damage from the nails and of course the hissing got worse. Having lots of sealant in the tire, I did what I could to lean the bike over on the side with the holes and roll it down so the goop could glop into the holes and save my bacon.

The hissing lessened but didn’t go away.

26×4.8 tires inflated to a street-legal pressure of 18 psi have a lot of air to give, so I jumped on the bike and got rolling fast; again with the idea of letting the sealant spread and seal. I got maybe a block before the lessened but continuing air loss meant it was time to stop and refill. Here’s where having the lightweight, emergency electric bike pump made all the difference. In short order I had the pump connected to my tire and battery and it began noisily refilling the now almost fully flat tire. Once the tire got reasonably firm I disconnected, stuffed the pump into the kangaroo pouch and got rolling, all the while hearing hissing, still. I repeated this process two more times on the way home. After the third refill, the hissing stopped. FlatOut sealed a massive series of holes and today, weeks afterwards, the tire is still holding that same amount of air.

It remains to be seen if the tire can be considered reliable for long term, long range use. I have been riding other bikes in The Pacific Fleet recently until I can take the time to do a full post mortem. But bottom line: FlatOut got me home and averted certain disaster. It gets my enthusiastic seal of approval.

The Bag Bumpers

Problem: the Great Big Bags are so big, they exceed the length of the frame structure. The padding keeps them from flopping around, but they can still curve inward and, on the drive side, touch the chain which is very close by. That chain is a chain saw on the fabric and you’d better not let it contact the bag for long. Also in the rear the bags can be worryingly close to the tires – still 2-3 inches away but it would be nice for them to keep their distance period.

Solution: Re-purpose the existing M5 bosses that Surly used for the stock Dummy Bag mounts. Attach a 36″ metal strip, whose function is pretty obvious just looking at it:

Figure 1: Initial test fit. This fit uses smaller washers and the strip is upside-down as noted below.

Pretty straightforward stuff. Whats not so straightforward? I think Surly did a pretty solid job of engineering this frame so its sturdy where it needs to be and flexible when it needs to be. They don’t need me re-engineering the give and take this frame was designed to deliver under load. So the challenge is to create a rigid structure that keeps the bags from intruding into the wheel well, but at the same time does not provide unexpected structural rigidity.

A stiffer frame sounds great, until you realize you are adding rigidity selectively. If flex is a part of the frame design, then its going to happen one way or another. I would rather it be distributed as the manufacturer intended rather than restricting all of the forces to exert themselves in a new spot, in a way the designers didn’t anticipate.

So here’s how we do that: first and foremost, I drilled an oversized (M10) hole at the front anchor point. Additionally, I sandwiched the connection in front and behind with rubber washers that themselves are captured on both sides by stainless oversized washers.

That big hole is off center on purpose. You hang the strip so it lies roughly centered. Then it can still flex without hanging near its edge (Figure 1 is a test fit and its actually upside down in that pic).

Also note the steel washers above were swapped out for wider ones to fully capture that rubber washer in between.

Just an oversized hole doesn’t fully allow the frame to flex as designed. You need a long slot in the back to further allow unrestricted frame movement. I created this by hand using a time-tested – and ugly – method:

  1. Mark your material with a Sharpie.
  2. Drill a line of pilot holes with a small bit. Yes it looks sloppy.
  3. Drill out the pilot holes with a larger (M6) bit.
  4. Hand file to a squared-off rectangle slot. Not quite finished in the last pic at right.
  5. File the face of the strip on both sides to debur it after all that filing.

When done, bolt it on. If I had this to do over again I would add another half inch of play fore and aft just to be sure I achieved my goal here.

Yes, of course I replaced that rusty old bolt after this test fit.

The Inexpensive, Custom Frame Bag

Custom frame bags cost a small fortune. Mine cost me $40 delivered to my doorstep. I use a vendor on EBay named Uraltour. Four bags purchased from that vendor so far and all are sturdy, heavy cordura with perfect fit around existing frame bosses and whatnot. You can specify width and since I am buying bags that will hold 18650 battery packs, I insist on a 10cm width. Maybe you can get away with 9cm. Don’t use the default of 6cm unless you have different needs. He will also work with you for shapes other than triangles.

See the little red whatsit up front? Thats my charge cable with a waterproof cover. Ask for flaps top front and rear for cables.

The downside? Well, his business name provides a clue: He’s deep in the middle of Russia. So mailing stuff from Russia to the USA can take at least a month and possibly two. My first bag took three. But thats life. A USA supplier would have provided me with excellent bags, at a much higher price point. Oftentimes they are booked up and you’ll wait months assuming they will take the order at all. Not being able to get a US vendor able to take my order was what made me go looking for another source and finding this vendor.

The Shelf

The space just behind the top tube on the Surly Big Fat Dummy – just ahead of the rear rack supports – is wasted space. A few owners have had custom bags made for this area. I more or less built my own cargo shelf out of odds and ends.

  1. A small bit of aluminum flat bar stock roughly 4″x16″ (I forget the exact size… I had it in my garage from a previous project where I was making a rack floor for another bike).
  2. Another small bit of flat bar stock, about 4″ wide and 10″ long
  3. Leftover 3/4″ ID Silicone hose
  4. Some leftover Great Big Bag closed cell padding
  5. An M6 bolt, washers, a nut, an unthreaded spacer, four zip ties and some Gorilla tape.

Showing pictures of the thing make it pretty easy to figure out how I used the above parts.

The silicone tubing is used to pad the frame. Just slit it down the middle and fit it over the frame tubes. It’ll hold and stay on its own.

Look under the bolt on the crossbar. There’s a spacer with washers underneath so the bolt doesn’t just bend the floor plate up towards the frame.

The padding covers the big floor plate, and the gorilla tape covers that to make a big padded shelf base.

The smaller flat bar plate and zip ties make for a backstop for the shelf. Its sitting at an angle and the last thing you need is for your stuff to slide into the wheel well. I painted mine black but gorilla tape could be used on it as well. Drill 4 holes for the zip ties.

If you look over at the post on A Proper(e)Bike ToolKit – which spells out the BFD’s tool kit – the cheapie MOLLE bag I use there is sold in a pack of two. This is where I use the other one.

This is how I carry along my super duper Pragmasis hardened steel noose chain and U lock.

I keep the keys in the bag with the lock so I never forget them.

The Quick-Detach, Carry-On Battery

I wrote this up as its own separate thing. Check it out here.

Big(ger) Brakes

The SRAM brakes that come stock on the Surly Big Fat Dummy are good, but on a bike that can take on extreme loads and terrain, they need to be great. I literally use the same brakes on all my bikes.

  1. Magura MT5e 4-piston brakes. The ‘e’ means they have a built in cutoff cable that I can plug into my BBSHD or hub motor.
  2. 203mm Tektro Type 16 rotors front AND rear. These are downhill rotors that are 2.2mm thick. Magura brakes are meant to work with 2.0mm thick rotors (typical quality rotors are 1.8mm thick). The Magura calipers will work with the Tektros albeit only barely with fresh pads. Often when I set up a new bike, I swap in partially worn pads from one of my other bikes and give that other bike new pads. By the time the new bike wears thru these swapped-in partially worn pads, the rotors have enough wear that they can take new Magura pads no problem.
  3. Magura MT7 4-piece pads. I still use the 2-piece MT5 pads that come with the brakeset, but as soon as they wear out, I switch to the MT7 pads, which fit perfectly. They have the performance advantage of delivering significantly more measured torque according to reviews. They also can be taken out with your fingertips without removing the caliper from its mount. MT5 pads on the other hand come out from the bottom and to do that you have to dismount the caliper. So better performance and easier maintenance.

The Big Battery

Fopr most of the life of this bike I have been using a 52v, 17.5ah battery pack I bought in 2017 from Luna Cycle. This pack has a 50a continuous BMS and uses 25R cells. The pack has been in use on three successive bikes over the years and has seen almost daily use, with two charge cycles per day since I charge at the office and at home. However, thanks to my ridiculously rigid adherence to best practices when it comes to battery charging, that pack has almost miraculously lost no measurable amount of its original capacity.

However, a bike this size eats power. Especially the way I ride. Recently I purchased a 21ah pack from this vendor and have been very pleased with it. It only barely fits in the Size Medium frame triangle, but it does fit.


The End?

For the Surly? Hell no its the One Bike To Rule Them All. Really, its a great bike and I intend to ride the wheels off of it.

Is it the end of the mods to this bike? Pretty much I think, with the exception of the summer wheels I’m making up using the MYOBDs and a pair of Apache Fattyslick fat tires, for that Kojak street commuter look. Since its a true slick, we’re talking summer wheels for sure. But maybe not as I live in California and like the old song says, it never rains here.

Kickstand Kaos

A whole page on a kickstand? For a bicycle? If you are riding a 100 lb freight train whose weight can quadruple when loaded up, there’s more to ponder over than you might expect.

The Surly BFD Project Menu
Prologue
Episode 1: 138L (each) Panniers… Seriously?!
Episode 2: Big Fat Dumb Wideloaders
Episode 3: Kickstand Kaos (you are here)
Episode 4: Add a Flight Deck. And a Hangar.
Episode 5: Leftovers
Episode 6: Electrification

The Surly Big Fat Dummy is a fantastic bike, with one widely acknowledged weakness: The kickstand.

There are those out there – possibly this includes the staff at Surly – who say this is a feature and not a bug. The BFD after all was created as a bikepacking, overland trailblazer. You don’t need no steenking kickstand since you can just lean the bike up against a cliff face, or an axe handle.

Begrudgingly it seems, the Big Fat Dummy is delivered with a kickstand that on any normal bike would be pretty sturdy. Alas on this monstrosity, it is adequate only when the bike is empty, and woefully inadequate when loaded.

How do I know this? Well, ask around any user group, but insofar as personal experience goes: On my first shopping trip with my new freight train, I went to Costco and loaded up four packs of soft drink cans. Since this was Costco, each of those four packs holds 36 cans. Thanks to a total lack of planning and intelligence on my part, I created a load where just the soft drink cans weighed over 100 lbs.

Memo to Me: When shopping on a bicycle, pay attention to how heavy the cart is before you leave the checkout line.

So, my wideloaders were sturdy enough to handle this. My great big panniers were more than big enough. But… how am I planning on loading the bike, then loading the (14 lb, 2-meter) chain and u-lock, and only then climbing on the bike and rumbling across and out of the parking lot? During this loading process, I learned first-hand how important a solid stand was. The next 15 minutes after this picture was taken were a big adventure.

Figure 1: All quiet at the bike rack… things are about to go horribly wrong.

Moving Forward

So, the problem is obvious: If you are using the BFD as a cargo bike and not a bikepacking bike, the kickstand is way out of its league. Has to be replaced. Period. Talking to folks on the various Surly user groups, the Rolling Jackass with its roughly $400 price tag is the best commercially-available solution.

Its DIY Time

I wasn’t ready to fork out that kind of money. I was bound and determined to build my own stand, and I had an idea. How tough could it be?

If you have seen my article on the wideloaders for the Surly Big Fat Dummy, you may have noticed (and seen mention of it in the post) there were some oddball fittings pictured that served no purpose in the published design. That is because I planned an integrated kickstand as part of that project.

The idea went thru a number of iterations. I started with the idea of using simple ‘pegs’: a 3-way elbow on the outside edge, with a length of tubing extending to the ground and terminating in a rubber crutch pad. Place it maybe in the front, or perhaps the rear. Perhaps one on each side, or maybe the front and rear of just one side… what about front on one side and rear on the other?

After mulling the possibilities, I came to the conclusion that every type of peg idea was fatally flawed. There was just too much potential for the bike to fall over while attaching the pegs, or removing them. Especially loaded.

I ended up settling on this: use a 4-way elbow joint on the inner, forward tube joints. Form the actual stand from two pegs attached to one another by another tube to make a ‘U’. And furthermore, make the ‘U’ stand up on its own with another 4-way tee sprouting two short arms that become stabilizing props. This will let the stand be placed in position without someone holding it while the bike is set up onto it.

Its a whole lot easier just to show a picture of the final product than it is to describe in words:

Figure 2: Crossbar with standy-up crossbrace thing completed

By the way, I used the same marine rail fittings that I used for the rest of the wideloaders, so these connections, with a little Vibra-Tite, are guardrail-solid.

The whole idea of making it self-standing was a happy accident sprouting from my need to turn two leftover short pieces of pipe into a full-length crossbar. the 4-way tee was a leftover itself, that I thought I was temporarily pressing into service. I didn’t think to add tubing and feet to the two unused, open holes until I glanced over at more leftover parts lying on the floor. Adding this self-standing (and load distribution) feature turned out to be crucial once I actually tried to use the stand.

Figure 3: This picture was actually taken before Figure 2, during initial construction/guesswork.

And this is what ended up working. I measured the vertical tubes so they only raised the bike up by a bit off the ground. This was crucial as attachment was achieved by lifting the front of the bike up and simply plunking it down on the stand. This is the part where inadvertently making the stand able to sit upright turned out to be (very) useful.

Attaching the stand is easier to do than it sounds. Load on the bike is on the back wheel. Lifting the front is not very difficult even when the back is loaded. And keeping the rise low on the stand is important because it means you don’t have to lift up the front too high.

Removal is also simple. Lift the bike up and the stand falls away (sizing is crucial for this to happen so the stand doesn’t hang up inside the fittings). Push the bike back an inch and set it back down. Grab the stand and toss it into your panniers.

It Works! more or less…

Success! And I still had $400 in my pocket, but… really… after using it for about a month every day, I found the attach/detach process was kind of a pain. As an exercise in problem solving… as a fun project… it was great. But as an expected convenience used with a daily driver. No bueno. And if you have wondered to yourself if, while lifting that bike onto, or off of, the stand it might just fall sideways… I had a few close calls but it never happened, even with a full grocery load.

Still, if your use of the bike is more occasional, this could be a viable option to add into your wideloader project.

Or skip the wideloaders, do a short front crossbar only, use simple single elbows for the stand pegs and work out how to flip it up and down… You could make just a stand with a little more effort and some smarts.

Figure 4: Kickstand/workstand in use

I ended up relegating the kickstand to a portable work stand, and bought the Rolling Jackass (they can both fit). In Figure 4 above I am at a city park, with the bike up on the ‘work stand’ so I can clean and lube the chain. The work stand does a better job than the Rolling Jackass because the latter can come undone if you mistakenly push the bike forward. Not possible with the fixed stand. I like doing basic maintenance at a park after a ride so the time and effort to make this stand was not time wasted.

A short Afterword on the stand…

I made one more improvement – sort of – that might be more successful for someone more determined than I was to see it through. There was a second issue beyond just lifting up the bike and putting it down onto the stand. That lift was actually fairly easy. The real potential for annoyance was if the stand shifted a hair, or my aim was off by a smidge, and the bike hangs up and sits atop one of the open tubes of the stand, rather than sliding into the fitting. Solution to that was to walk over and give it a little kick which, 9 times out of 10, would work. Sometimes not if my aim was really bad, though, and I would have to retry the process. Like I said: an annoyance.

The boat rail fitting itself has an internal chamfer to make fitment easier. And there is quite a bit of extra material there to allow you to hog it out further to make a much bigger well. That would work great. But these are steel fittings about 3mm thick. My poor little Dremel’s grinding wheels just polished that steel and little else. Something bigger and badder was needed and I wasn’t up to it at the time (the job needs a drill and a big internal chamfer bit).

Instead, I rounded off the ends cheap and easy with 7/8″ round end caps. this worked perfectly, but the caps are so tall they make the stand a bit wobbly, since so much less of the pipe is now in the socket.

Pop this onto the tube end. Problem solved.

Whats Next?

So, we went round and round with the kickstand and in the end, bought one and use the other for a work stand. Fine. I’m not done yet as there is one more goofball problem to solve.

Where I work, I am lucky to have my own private garage where I can park the bike, hook up a charger, turn on a couple of industrial fans to blow the sweat off me and change into proper work clothes. I’ve even got a small air compressor, a big rug and a nice padded chair.

There’s only one problem… to get into that garage I have to make a U turn through a narrow walkway under some stairs.

Figure 5: uh oh…

It was never an issue until I built a bike almost three feet wide and over 8 feet long. Yeah I sort of didn’t really focus on that until after I had the build completed. You’ve probably heard the story about That Guy who bought a pickup and then realized he couldn’t fit it in his garage? What an idiot, right?

Problem Solved!

Use the little dollys that people use to move around pianos and pool tables.

Figure 6: Choose your product carefully. A lot of them have horrible reviews.

Throw one under each leg of the kick stand and just wheel the thing around as you please. Easy peasy.

Figure 7: Hello Dolly! Note the Rolling Jackass, and the still-in-place elbows for the ‘work’ stand.

Moving the bike into the office garage through that narrow entryway is a snap. Without them its still possible but involves a lot of dragging and lifting and fighting and cussing.

Last But Not Least (At Last!)

Take a close look at Figure 7. At the feet of the Rolling Jackass kickstand. Underneath them. Looks like some kind of disc or foot? Well, it is. If you refer back to the Frankenstein boots for the Ursus Jumbo, I did essentially the same thing here. The idea was the steel feet of the Rolling Jackass – are thick steel. they will probably last a long time, but I want them to last forever. I also park the bike in places where I do not want the floor scratched (like the marble floor of my bank’s lobby. Yes really).

Using the same process I described in my other post on the Jumbo, I layered on about 10-12mm of Shoe Goo… the artificial shoe-leather. It became a flexible but durable sole to the Jackass’ steel shoes. Before applying the Goo, I roughed up the smooth steel surface of the feet with some power tools.

10-12mm may seem thick, but that thickness is necessary to keep the edges of the steel feet from digging into the ground as you lever the stand into the down position.

The security guard at your bank will thank you for taking the time to go that extra mile.

Add a Flight Deck. And a Hangar.

The Surly Big Fat Dummy has a great big deck in the back. Using a 40″ kicktail longboard and some hardware, Lets make it bigger. And a double decker to boot.

The Surly BFD Project Menu
Prologue
Episode 1: 138L (each) Panniers… Seriously?!
Episode 2: Big Fat Dumb Wideloaders
Episode 3: Kickstand Kaos
Episode 4: Add a Flight Deck. And a Hangar (You Are Here)
Episode 5: Leftovers
Episode 6: Electrification

In the Beginning…

Back when I put together the Mongoose Envoy Project, I used a skateboard deck to cover over the long, but only marginally-useful-on-its-own rear framework to create what ended up being an aircraft carrier landing deck.

I started out with a 33″x10″ double kicktail which I mounted on top of eight 25mm tall by 13mm dia. spacer posts. The idea behind the spacers was to give me some working room to attach a net to the top of the deck, and have room to easily mount its hooks to those posts. It worked well, but I left money on the table with only a 33″ deck. I could go longer. So I did. I found a 40″ longboard with a single kick and mounted it on 10 posts, this time.

It was great, but of course, I thought I could go one better. So I scored a 44″ double-kick longboard, and – since the 25mm posts were a bit fiddly trying to get my fingers in that small space – swapped out for taller 40mm replacements. I also made some other improvements, and that deck remains on that bike as you see it here to this day.

Fast Forward To The Present…

Now I have a Surly Big Fat Dummy, and I want to do the deck idea one better (AGAIN!). I still have the 40″ deck left over from the Mongoose build. Since the BFD is already like 8 feet long I don’t need something that makes it longer, so this ‘shorter’ deck will do just fine. I drilled some new holes, repainted it and took the spacers a step further.

The Next Level (literally)

Unlike the Mongoose, which had nothing but a framework, the Surly Big Fat Dummy already has a pretty good deck as it is. On the Mongoose Envoy I was trying to cover over the bare framework and make something useful. This time I am trying to make something already useful more so.

To preserve the utility of the existing deck, I went with much larger spacers. That created a ‘hangar’ under the deck of this aircraft carrier of a bike. This new hangar’s purpose is to house things that need to be carried along, but generally kept out of sight. Stuff where I can benefit from it being reasonably handy, but kept out of the way.

Great Idea. But first I had to assemble the parts and make the thing.

To give plenty of room between decks, I went to McMaster-Carr and acquired ten 3″ long alloy spacers, 5/8″ outside diameter, sized for 1/4″ bolts. Then I went to Pegasus Auto Racing and, after measuring the exact stack height I would need, grabbed ten AN4 1/4″ hardened airframe bolts of the proper length, along with ten AN970 hardened large-area washers for 1/4″ bolts (for the top deck side) and a bag of AN960 1/4″ x 0.32″ flat washers, where I would need 30 for the deck underside, plus the top and bottom sides of the alloy dummy deck. I wrapped up the party with ten AN365 nylock hex nuts.

Airframe bolts have a specific thread length designed to fit a single bolt and a single double-thick washer. This project uses 4 washers of two different varying thicknesses. Measure carefully.

Wow thats a lot of hardware

Like my previous decks, I wanted to use enough spacers and bolt anchor points to make the deck an integral, structural part of the frame. No wiggling possible. Part of what it takes to do that is to use the widest spacers I can find (the 5/8″ OD are it, and dictated why I couldn’t stay metric). To further solidify the connection laterally, I needed washers everywhere clamping everything.

You can still see the holes from when the deck was bolted to the Mongoose, as well as the holes for the trucks that aren’t there anymore.

And excepting the spacers themselves, its all Grade 8 hardened steel. Its. Not. Moving.

Notice also I used hex bolts and did not bother to work with countersunk heads, matching washers etc. as with the previous decks. This thing is spray painted in truck bedliner to help keep things from sliding around, and the hex bolt edges do the same job.

Airframe bolts exist in a wide variety of very finely diced sizes. I am not giving the size I used because the ones you may need will vary according to the thickness of your top deck.

Here’s what the finished assembly looks like up close:

Now that the aircraft carrier has a landing deck, we find out what we stuff down underneath in the hanger.

Up front, fitting just barely between the front posts, is a 3-amp weatherproof adjustable charger that is a permanent companion to this ebike. In the middle is the toolkit for this bike, containing a pump and all sorts of other goodies. It fits just between the two sets of spacers so it can be dragged out the side. And in the back we see a big thick plastic ziploc freezer bag wedged in between the rear 4 stanchions. Thats the in-case-of-disaster emergency inner tube.

Since then I have added another little jewel:

Thats right. A folding chair. Held rattle free thanks to the net. Stuck in line at curbside pickup? Have a seat and relax.

Take the crap off the top of the deck and you have yourself a work table. Or a coffee table. Or a picnic table. Its 40″ long so use your imagination.

See that net? Its 30″ long before it gets stretched out, and since I ordinarily have the Great Big Bags on the bike, I generally do not need to use the top deck for storage of items up so high. But when I do, that nice long cargo net does a great job.

Here is one of the rare times the bags are full and I need to stack something up on the deck other than a rolled up jacket

Now What?

Got a Big Fat Dummy? And a drill? And a skateboard? Make yourself one of these. Next time you have to sign a peace treaty, host a banquet or make off with an emergency supply of toilet paper… you got this!

Quick Release, Easy-Carry Ebike Battery Setup

Parking your ebike outdoors all alone? When shopping, my cargo bikes are locked but out on the street… but the battery goes in with me. Here’s how I do it without people thinking I am carrying a bomb.

Yes You Can Take ‘it’ With You

An ebike used for utility purposes is, by its nature, going to be left out a lot. You go to the store, load up a shopping cart, come back and fill up your saddlebags. You really want all the parts on the bike when you left to still be there. Especially after loading on 50 lbs of cat food, Oreos and diapers.

The most obvious way you keep the bike itself is to use a good locking strategy. I’ll save that for a different discussion. This time I will focus on how I protect the single most-expensive component on any ebike – the battery. Not by locking it up, but by making it so I can do a quick grab and carry it in with me.

By removing that battery, we are making that big heavy ebike into a boat anchor, which we can hope makes it at least a little less attractive to thieves.

Size (and Shape) Matters

What I am describing can be made to work with any shape battery, kept anywhere on your bike. What you see here works best with a squarish, oblong battery. In the pics below I am using a 17.5ah Luna Storm battery, which is pretty big and heavy (in part thanks to its powerful but not-so-energy-dense 25R cells). More likely, if you have a similar heat-shrink battery pack like this one, its quite a bit smaller and lighter.

I also keep a Luna Wolf Pack battery like this and do not use its magnetic mount. The battery is easy to quickly get off that mount, but leaving it inside of a bag like I describe here is, overall, easier than stuffing it in every time, taking it back out and so on. For packs like this (Wolf, Shark, Dolphin etc.) you could certainly bring a small pack and put it in/take it out as a part of your routine.

There’s more than one way to skin this cat, so what you see here is just a jumping off point.

Lets Get to It

This is the battery in its bag, just like it would be if I rolled up to the local Costco.

Ignore the charger cable in the front. I took this pic at work in my ebike garage.

If we zip open the bag, we don’t see a battery. We see an inner bag, along with that charger cable extending thru to the rear. The controller cable is in there too just out of sight (look closely and you can see it)

If we look inside the bag, we see the battery charge cable is in fact an extension running from the rear of the interior bag up and out the front. The motor cable – an XT90S connector – also has a short extension between the battery cable and the motor cable. The idea is this: when routinely, frequently detaching and reattaching the cable, if there is any wear its on a cheap, replaceable extension and not a critical, live/hot cable coming directly off the battery.

Disconnect the cables and give a tug to the inner bag. Here its shown halfway out but you will just pull the thing out in one motion.

When I leave, I generally put the cables back inside and zip it only halfway-ish, so its obvious there’s nothing worthwhile to steal inside. Move along.

Annnd here we are. the cables are shown sticking out of the inner bag. You will want to cap those for safety’s sake. I use cheap plugs I got a bagful of on Fleabay for a couple bucks.

And yes… as-is I have had someone ask me “what is that a bomb?” … only half joking and ready to clock me if I make a sudden move. So stuff the wires in the bag so they don’t stick out.

Tell the Bomb Squad to cut the red wire

Done! Wires are capped and stuffed into the bag in 5 seconds. The sling strap goes over your shoulder for easy carry. I just lug it to the nearest shopping cart and put it in the bottom rack with my helmet and off I go.

This is just a 3L hydration bladder pouch, the sling strap that comes with it and a shoulder pad I swiped off another strap I wasn’t using.

Parts

Its a really short list with one item on it.

Hydration Carrier

You see above the Blackhawk S.T.R.I.K.E. carrier in use. Purchase link is here. Yes, the name is a tad ridiculous. But this pack is minimalist and is just durable cloth with no insulation or padding. Its easier to stuff into a confined space. Mine came with a super sturdy velcro sling strap.

Another that is well made (and a tad smaller for a tighter fit is sold by Voodoo Tactical. It comes with thin backpack-style shoulder straps that don’t take up *too* much space in your triangle bag and are not enormously fiddly when stuffing back in there.

Another one I use (with my Luna Wolf pack) is this government-issue USMC carrier. The link is to a brand new unit. I got mine surplus and cheaper on Fleabay. This pouch has no straps (you can clip on your own from a duffel bag if you like) and it is the opposite of the Blackhawk carrier: Its thick and padded. I can still stuff it into any triangle bag I have despite this. Its great as a protective layer over a battery.

Wrapping It Up

There are lots of ways to do this. How I do it is no big deal. Key takeaway here is to find a method that works for you so you can swiftly grab the battery, go off to your next adventure and then come back and plug right back in again.