Bafang BBS02B eBike Conversion

My first attempt at an eBike was a FWD 36V 500W conversion of my old Infinity Boss.three Disc Ladies bike, but due to some poor design decisions, that never worked out. However, I did have a perfectly good 36V 10s2p 21700 battery pack begging for a worthy home.

In Summer 2024 term, I picked up a 90's era Peugeot Quantum MTB. Given the nickname Rattlecan, it was a rundown dump, but just $35. New cables, housing, brakes, tires, bottom bracket, pedals, seatpost, and seat later, it was a well working bike! I know, the r/xbiking classic of spending more on the parts than the bike. After riding it as a commuter and underbiking the hell out of it in the Hydrocut trails, I felt it was the perfect candidate for an eBike.

A middrive setup felt like the best setup: easy tire changes, great torque thanks to using the existing drivetrain. With the Bafang, you have a built-in motor controller, so you just need to connect a battery, making for a super clean setup. I also set it up as pedal assist (PAS) only to take advantage of the very natural feeling of the middrive and cadence sensor. Out of all the motors available, the BBS02B has great spare parts availability and seemingly better reliability than the Tongsheng TZD series. I felt that 36V 500W version was the perfect amount of power after my experience with working at Electrium.

Putting together the kit was a very straightforward experience:

• Bag: Rhinowalk frame bag to hold the battery, a Flipsky Antispark Switch Pro 200A, and excess cable. The bag has a super handy port for a hydration bladder, which turns out to be the perfect spot for a cable passthrough and mount for the antispark switch. The frame bag really helps sell the non-electric vibe.

• Display: DZ40 mini display, which is a very compact and discrete display. Simple battery level, speed, and PAS level display. However, it would be nice to see the battery voltage, and the battery level takes a weirdly long time to appear after startup.

• Electronics: Everything is connected using Anderson PP45 connectors. I've had far too much trauma from trying to solder XT60/90 and melting connectors or having poor solder joints, so the crimped Anderson connectors are beautifully simple and fast to install. I have the retaining pins installed for extra security. I've included a Flipsky antispark switch - why not? Zip ties hold everything neatly in place.

Warning: For anyone considering a similar setup, the motor stabilizer bar is mandatory. I purchased mine from Golden Motors. The default mount relies on painted, round, soft steel teeth biting into the sides of the bottom bracket via pressure provided by the inner lockring. For me, these terrible teeth stripped instantly. The stabilizer bar is a much more reliable setup.

Do I like it? Hell yeah! It's incredibly fast, where PAS 1/5 makes it feel as light as a road bike, and PAS 5/5 makes it a rocket ship. Keeping it at PAS 1/5 helps extend the range of the tiny battery, and the setup is reasonably lightweight. The PAS is reasonably smooth and natural. The whole setup is very sporty and slick.

Future Steps: I would like to upgrade the brakes, with this motor easily overwhelming the terrible Altus cantilevers I have. Plus, tidy up the wiring by wrapping it in heat shrink, improving the waterproofing, and print a housing to securely present the charging port and power button. Far future additions might be a motor bash guard and moving to a proper electronics enclosure. At present, this is a dry weather-only princess.

When I first got this Peugeot,  I went with Altus CT91 cantilevers. The retro vibe and overall look of cantilevers are just fantastic. However, I've never been able to set them up right. Cantilevers have so many things you can fiddle with: hanger angle, tension, pad positioning, etc. and it's just way too much of a fuss for me to handle, even if they could be as good as V-brakes. When they started off, they had acceptable stopping power, but the front brake eventually developed some horrid "clicking" sound.

So, out with the old and in with the new! Alivio BR-T4000s, which were a very comfortable $25 each. Even though I've never seriously worked with a V-brake bike, these were super intuitive and a breeze to set up. Add some new housing and Avid FR-5 levers, and these things, despite their cheap price, are almost on par with some hydraulic disc brakes I've tried. Their only issue? Absolutely no modulation, so either you're going, or you're not. Great for some fun skids though!