Bafang BBS01 conversion

[Dewey]

I wrote a blog post on my experience converting a pedal bike with an IGH using a 36v 250w BBS01
https://ebikelovers.com/2021/03/18/converting-a-pedal-bike-to-an-e-bike-my-experience/
The threads on UK Pedelecs helped me decide to go with the BBS01a back in 2016 when I bought the kit, it’s not as popular where I live in the US as the BBS02 and HD, but as the assembly is similar I thought it might be good to encourage others to have a go. Thank you for the knowledge I’ve gained reading this forum

 

[jimriley]

I noticed you fitted a torque arm, was that standard at the time? My bbs01b didn't have one and doesn't seem to need it.

 

[Fordulike]

I noticed you fitted a torque arm, was that standard at the time? My bbs01b didn't have one and doesn't seem to need it.

Whilst it's true that the BBS series of motors do exert a lot of rotational torque (correct term?) at the bottom bracket, especially the BBS02 and BBSHD. As long as the mounting plate is fitted with the knurled side facing inwards towards the bottom bracket housing, and the two lock nuts are torqued down with the correct installation tool, there should be no issues with the motor moving under use.

 

[Dewey]

I noticed you fitted a torque arm, was that standard at the time? My bbs01b didn't have one and doesn't seem to need it.

Hi Jim, I bought it last summer from the shop that sold me the kit. For 4 years I’d had a merry time removing the crank arms about every other month to tighten the lock ring. The stock Bafang BB mount just isn’t good enough, and I’m much happier with the torque arm, it should come standard with the kit.

As parts are getting rare for the ‘a‘ model, I bought an early BBS01b motor core without the light connectors, cheap, to swap in when the time comes.

 

[Deleted member 33385]

Hi Jim, I bought it last summer from the shop that sold me the kit. For 4 years I’d had a merry time removing the crank arms about every other month to tighten the lock ring. The stock Bafang BB mount just isn’t good enough, and I’m much happier with the torque arm, it should come standard with the kit.

As parts are getting rare for the ‘a‘ model, I bought an early BBS01b motor core without the light connectors, cheap, to swap in when the time comes.

You could add a bit of blue threadlocker. If the lockring on my BBS01b comes loose again, I'll be doing that. The tool I have is open on one side, it's (just about) possible to tighten the lockring, without removing the crank arm:

Bafang Installation Tool Multi-Function Wrench Installing Fitting Tool Kit for BBS01 BBS02 BBSHD : Amazon.co.uk: Sports & Outdoors

Shop Bafang Installation Tool Multi-Function Wrench Installing Fitting Tool Kit for BBS01 BBS02 BBSHD. Free delivery and returns on all eligible orders.

www.amazon.co.uk

Of course, it helps if the ridges behind the mounting plate which bolts 1 & 2 go through, bite as deeply into the frame as possible. But you've probably already mounted that plate the right way round, or you would have had much more tightening to do, much more often.

 

[Fordulike]

You could add a bit of blue threadlocker. If the lockring on my BBS01b comes loose again, I'll be doing that. The tool I have is open on one side, it's (just about) possible to tighten the lockring, without removing the crank arm:

I guess that where you've quoted 'just about' with the open ended tool, that you have the same problems I had when I used one of those. It's just too thick and wide, obviously to offset the structural weakness from being open ended, to do the job easily. I ended up spending more time faffing about getting a purchase on the locknut, than actually tightening it.

I now use one of the fully enclosed tools like this one, and find it much better suited to the job:

Installation Spanner/Tool for Bafang/8Fun BBS01, BBS02 and BBSHD Mid Drive Bikes

I will repeat what I said earlier. If the mounting plate is the correct way round and the locknuts are torqued down tightly, then there should be no issues with the motor unit moving about with use.
My BBS02 has been programmed for pretty much max power and it has never shifted.

If I did need to tighten or untighten the lockrings, then it's easy enough to either remove the crankarm, or even easier, remove the pedal to gain access.

 

[Deleted member 33385]

I now use one of the fully enclosed tools like this one, and find it much better suited to the job:

Installation Spanner/Tool for Bafang/8Fun BBS01, BBS02 and BBSHD Mid Drive Bikes

Yes I almost bought one of those, but then I realised that the ridges under the mounting plate needed a litle time to bite into my soft aluminium frame after the intitial tightening, and that a second tightening the following day was needed. It hasn't shifted since, but if it does I'll be blue threadlocking it. If that doesn't work, it'll be the red variety. The supplied open ended tool, just about manages to tighten, without having to take the crank arm (or pedal) off - when it's off and you have the right angle, it works a lot better... but probably not as well as your tool, which I might still get.

 

[cannon]

In addition to threadlock I used a small "pad" of metal epoxy between the motor body and down tube to take some of the torque reaction and also a little inside the bottom bracket to remove any clearance inside the bottom bracket. This has worked well on a BBS01 and 02.

 

[Deleted member 33385]

In addition to threadlock I used a small "pad" of metal epoxy between the motor body and down tube to take some of the torque reaction and also a little inside the bottom bracket to remove any clearance inside the bottom bracket. This has worked well on a BBS01 and 02.

That's a good idea - I avoided permanent stickies because I wasn't sure if my BBS01b kit would work out well on my Dahon Helios P8 folding bike... but is has. So I might just do as you've done!

 

[cannon]

I recently swapped my original BBS01 for a BBS02 on the mtb. The "pad" under the small motor came off fairly easily, however I may have applied a smear of grease before applying the metal epoxy to enable later removal but cannot recall. The main aim was to give the motor something solid to push against.
On my very first conversion on a old Cannondale I used a rubber pad, but the motor did work loose and dented the downtube slightly...hence the solid metal epoxy pad.