Bafang BBS02 grinding!

Frogprints

Just Joined
Jul 1, 2019
4
3
Northumberland
My Bafang assisted Dahon is only a few months old and used for only about 500 miles so far. A short while ago I detected a grinding through the left pedal, initially I thought pedal bearing but after replacing the pedals -no change.
I have stripped the motor down and cannot detect any noticeable damage to any of the bearings or the shaft, should I replace the bearing as a matter of course? If so best source for spares?

I read elsewhere that lubrication, lack of from the factory, is not uncommon but the bearings are reasonably well greased.

Any suggestions?
 

Frogprints

Just Joined
Jul 1, 2019
4
3
Northumberland
After reading further and came across 'creaking' which better described my symptoms, I reassembled the motor and made sure the cranks were good n tight - job done! Newbie mistake, look for the most complicated rather than the most obvious reason
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
3,431
1,314
Tyne and Wear
It would be nice to have a sticky thread, which people can refer to when fitting a kit, and for general tips for bikes already fitted with a kit.

I suffered from a creak for a while on my BBS02, which bugged the crap out of me. It was only upon extensive investigation, that I found the motor unit lock nuts weren't particularly tight.
The BBS motors produce a massive amount of torque and can cause the whole unit to move about in the bottom bracket housing. It may cause noises, but potentially all that movement could damage the bottom bracket housing.

I bought the proper tool for the job and tightened the two lockrings down nice and tight.
Some people might just tighten the outer one hand tight, but this is not enough to stop the motor from moving about. I periodically check the tightness with one of these:

https://www.ebay.co.uk/itm/Installation-Spanner-Tool-for-Bafang-8Fun-BBS01-BBS02-and-BBSHD-Electric-Bikes/283029843305?hash=item41e5e4ad69:g:gPcAAOSwR7Bbfugo
 
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weealan

Finding my (electric) wheels
May 5, 2019
12
1
53
central Scotland
Hi Fordulike
Did you have any problems with fit and finish of the spanner you linked to,,i did notice cheaper ones on ebay but would rather pay a few pounds more if it would last longer.
cheers
Alan
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
3,431
1,314
Tyne and Wear
I am pretty sure the outer ring in aluminium and over tightening will strip the threads . I put a little loctite on the threads and make sure the first nut it tight and just tighten the second one up just enough to keep it in place
I have tightened that outer ring very tightly and it didn't feel like it would strip the threads. Certainly on my BBS02, if I don't tighten those two rings down nice and tight, the motor unit eventually loosens with all the torque it produces.
 
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