Bafang BBS02 grinding!

[Frogprints]

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]

Should have said BBS01B!

 

[Frogprints]

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

 

[weealan]

Glad it was an easy fix/cure for you.And thanks for the update on what the issue was,(bbs01b owner myself).

Alan

 

[Frogprints]

Thanks Alan, thought my 'rookie error' may prove useful to others

 

[Fordulike]

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

 

[weealan]

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]

Fits perfectly on both lock nuts. Feels sturdy too.

 

[weealan]

Thanks for that Fordulike,,i will get one ordered when i return home from holiday.
Cheers
Alan

 

[Spider]

Some people might just tighten the outer one hand tight,

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

 

[Fordulike]

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.

 

[dimykha]

Hi everybody, I disassembled the pedal bearings of my Bafang BBS02 because I heard a crack at every pedal turn. Now I have several questions before reassembly:
- the ball bearings are thrust bearings, ie to prevent axial movement. I see that there also are guide bearings (for radial movement) which correspond to the machined portion of the axle. Nobody speaks about these guide bearings. Do they also need maintenance ?
- to reassemble the thrust berings there is two nuts: a thick one and a thin one. Which one is to be installed first ? I did not take note at disassembly. I would say I should begin with the thick one, but can someone confirm? Also how shoudl I tighten it ? Should I apply a maximum torque or should I leave some play before tightening the second nut?
Thanking you

 

[Fordulike]

Thick nut first, then thin one. As it's almost impossible to hold the thick nut still, whilst tightening the thin one, I use Loctite threadlock (blue) to prevent the nuts from loosening. I tighten just enough to stop any play in the axle, but not too tight as to stop the axle from turning freely.

As for the axle support bearings you mention. I just put a small dab of bearing grease on each one, before inserting the final drive assembly.