Fitting a bb motor after market

Electrically assisted bikes, trikes, etc.
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Joined: 29 Mar 2007, 4:10pm

Fitting a bb motor after market

Postby belgiangoth » 20 Sep 2020, 5:18pm

Is this totally crazy (as in requires frame modification)? Or is it a case of bb swap page?
If I had a baby elephant, it would point out that there is no evidence for planing. Then it would eat all my bananas.

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Joined: 1 Apr 2020, 3:37pm

Re: Fitting a bb motor after market

Postby Trikesnbikes » 21 Sep 2020, 5:31pm

I have fitted bottom bracket conversion kits to several cycles. They are not perfect but they do the job and have been largely reliable. They do require "standard" bottom bracket dimensions i.e. 68-73 mm width.

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Location: West Sussex

Re: Fitting a bb motor after market

Postby hemo » 21 Sep 2020, 9:51pm

After market BB mid drive motors are available, just a few to name and available.
Tongsheng TDSZ.
Bafang BBS.

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Joined: 6 Jun 2018, 10:24am

Re: Fitting a bb motor after market

Postby stodd » 27 Sep 2020, 10:05am

Look at Woosh for a couple of crank drive kits:
Manufacturers from the list above. I think they usually have more choices but supply is short at the moment.
If you send them details (and pictures) of the bike they'll say if it is suitable and any issues you may have.
They will also provide generally excellent customer service before and after any sale.

As above, bottom bracket width is important.
One common issue is brazed gear cable guides under the bottom bracket; many BB kits fit snug under the bottom bracket.
Can be resolved if you don't mind grinding them off and rerouting cables.
You may have issues with front gear options.

Some people (including Woosh) have said that BB kits are even easier to fit than hub kits; as long as you have the tools and knowledge to deal with bottom bracket replacement.

If you are thinking seriously about this rather than just wondering, also look on ... ussion.42/