Bafang Mid-drive?

Good day kind Sirs and Madames and those who don’t subscribe to archaic paradigms of binary gender identity. I’m looking to convert my wife’s mountain bike into an e-bike.

The goal is to give her some assistance if we’re out for a full day as she runs out of steam long before I run out of watt hours. I also need to make sure this motor has some torque as we regularly haul our 2 kids behind our bikes for a combined weight of about an extra 85 lbs. Going up even a modest hill is a total cluster fuck and a huge disincentive to bringing them along.

Wondering if anyone has had any experience w the bafang mid-drive conversion. This looks to be a premium product and a price tag to match. Cells on the 18ah pack are Samsung 35e. I would happily build my own pack and save some doh and have much more piece of mind knowing the pack is safe and will likely go this route. Would be looking at the 250 or 500 watt options as 750 is overkill and can easily wheelie the bike w a throttle error.

C$ 507.63 21%OFF | Bafang BBS02B 48V 500W Mid Drive Motor 8fun Bicycle Electric eBike Conversion Kit mid drive ebike kit Newest version

I’m not interested in a front hub conversion for various reasons and want this bike to still be functionally more-or-less the same mountain bike as before the conversion. I realize I will loose some gears in the process but the ratios that will be left should be an acceptable trade-off.

For reference, I would be installing the kit on this bike:



DO NOT get that kit. Get the BBSHD kit. Last longer and more powerful. Also, get an aluminum loose tight tooth sprocket.

Might consider getting it from Luna, as they can be counted on as a brick and mortar with warranty.

Motors - Mid Drive Kits - Luna Cycle

What do you mean by this? Like the build quality is better or are you referring to battery range? I def don’t need 1000 watts. 500 is plenty.

This guys does a pretty good side by side. It seems failure in the B2 units are likely due to voltage spikes from a controller w not enough headroom to run 13s. I plan to only run 12s anyway.

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There were problems with the smaller earlier motor. Cant remember now, but if you are towing, it is especially important.

There is no doubt that in full power mode the 750w version is very quick, and a lot of fun to ride. Power-wise, there really isn’t a lot between the BBS02 and the BBSHD, although the latter has a lot more grunt, and the motor and controller can handle the extra power for a prolonged amount of time, whereas the smaller motor can become unreliable when subjected to constant hard off-road use.
Bafang BBS02 Review - How Reliable is it? | eBike Choices

Runnning 12s will hamper useability, and certainly towing. The system is MEANT to use 13s, as that is what the fuel gauge is based upon. And run hotter.

You can either use the full power of the s2, or loaf along with the bbshd. Remember, JUST ONE blowup, and it will more than eat the cost diff between the two.

I would especially not use the throttle. And you must continually touch motor, to see if too hot yet.

Many of the lessons learned on the s2, were put into the bbshd.

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I covered nearly 2000 miles on a 52v BBS02 powered bike for a year, without even a hint of a problem, but I only used the bike as pedal assist and very rarely went beyond power level 3.

Like your article, I only use pedal assist, and rarely go over 3, but I dont know if he changed program for 9 steps of assist.

Following these rules, you get a lot of range, less overheating, and your kit will run a long time.

PARTICULARLY women should be told not to use throttle, unless they are avid bicyclists, and understand intuitively, shifting, and keep the motor in easy fast spin.

And also important, if you follow these rules, you do not need a gear shift cutout module.

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You make some excellent points re heat dissipation which would certainly become an issue towing the kids up hills. I pulled the trigger and went with the bbshd. The other thing that compelled me was that there is a robust aftermarket scene w this motor.

Re a loose-tight alu sprocket Lekke seems to make one as well as Luna. 44t? Gear ratios are a bit of a question for me.

My wife proceeded to advise me that she’s running a triathalon in the summer and she needs an unmodified bike to do that so this is going on my bike now :call_me_hand: And being a DIY’er I IMMEDIATELY started looking at ways to hotrod it hahahahaha.

An external controller seems to be the easiest way to make it more reliable. As far as I’ve read, the heat dissipation is a major issue bc the motor sprocket is made from nylon which has a tendency to melt. I’m looking for a 72v after-market one that’s a bit more robust and a 20s pack to keep heat down while delivering adequate power. If I can manage the latter w a sinewave controller the former will not be a worry.

Done any tinkering on any of this stuff? Endless sphere has a bunch of users who have upgraded using a Lyen controller but I’ve never heard of them before.

Dont touch a thing. You start to get into the weeds if you modify. It becomes a drag car equivalent.

Simply follow the rules set out, and all will be fine.

The LUDICROUS controller, is nice, and would be fun for the dirt, but it adds massive maintenance and such.

Since you remove the front gears, it means that you have limited speed. And means that in PAS mode, your pedal cadence is a bit fast. Those that go ludicrous, must also go low gearing, and that limits the street use.

I go 30 at top speed with peddling, for a good distance. With only throttle, about 33mph. THAT IS FAST. Call luna, and tell them your uses, and let them suggest the gearing. Get a heavy duty chain.

The bbshd is wayyyyyyyyyyy too fast to be legal already.

By the way, starting out from a stop, and changing gears properly, I am far faster than the cars taking off. Till about 15mph. That gets you seen and avoided well.

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Ya I’ll stick to a 13s and stock. Whenever I see that something can be modded I IMMEDIATELY get carried away :sweat_smile:

Maybe I’ll mod a fat tire at some point down the road . Thx for the advice brother :pray:

I went Shwalbe marathon plus, 46mm, PHAT, on wide carbon wheels. It is plush and sticks well. They will last a few thou miles, and do Aight in dirt. There are others that are more dirt etc. But most important, they are called immune to flats. And have a reflective stripe.

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