Bafang BBS02 B Motor One way bearing problem ?

b.strat

New Member
Region
Europe
Hi there,

I've been riding a bafang BBS 02B for 3 years and now 6000 kms. Yesterday, I had a motor transmission fault. let me explain :
When I pedal without assistance, no problem.
As soon as I activate the assistance and the motor tries to “catch up” with the rotation of the crankset, 1 time out of three I get a particularly strange noise. It's as if the motor isn't engaging the crankset properly.

From my point of view, it seems logical that the problem comes from a freewheel. What do you think? I heard there were several freewheels in the motor, which one could it be?
Here is a video of the default :

Thanks in advance !
 
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Just taking a guess... But perhaps it's the clutch.

bafang-8fun-bbs01-bbs02-pawl-clutch-pedal-freewheel-for-replacement.jpg


 
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I also lean toward the pawl clutch as the suspect. It allows the motor to turn the big internal drive gear (attached to the chain) faster than the feet.
 
Seems to be.
Does it make the noise with the large gear removed?
Not sure if it will run without the PAS magnet disc though....
 
Looks like the rollers on the nylon gear bearing are worn. I'd replace it and the adjacent gear at a minimum.
Since you have it disassembled you may want to do a complete gear replacement as I believe they're not that expensive.
 
Looks like the rollers on the nylon gear bearing are worn. I'd replace it and the adjacent gear at a minimum.
Since you have it disassembled you may want to do a complete gear replacement as I believe they're not that expensive.
They doesn't look worn for me (expect the rusty color) but your are right, considering the price i's a good idee to replace them.

here is a the video of the motor without the large gear :
(the knocks when varying speeds were due to a lack of lubrication. once better lubricated, no more problems.)

 
I have near 12000 miles on my BBS02B without issue.
I lubricated it with Mobil SCH100 every 3000 miles starting at 1000 miles.
Maybe lube it up and ride a bit... If the problem is gone, then we all learn something today. 👍
 
Thank you for the lubricant reference.
You only use this lubricant for everywhere ? (gears, free wheel and bearings ...)

I will order everithing to maintain the motor (nylon gear, gasket and freewheel) just in case.
Mine has 5000 - 6000 Kms, i will service it sooner next time ;)


Thanks for your time and nice weekend :)
 
Here's a thread about greasing a mid drive motor.
It's got some relevant grease information.

 
Thank you for the lubricant reference.
You only use this lubricant for everywhere ? (gears, free wheel and bearings ...)

I will order everithing to maintain the motor (nylon gear, gasket and freewheel) just in case.
Mine has 5000 - 6000 Kms, i will service it sooner next time ;)


Thanks for your time and nice weekend :)
I only greased the 2 gears under the plastic cover. I've never disassembled further than that.
If you have a UART motor and haven't adjusted the Stop Decay, I highly recommend you give it a try. I think I ended up setting it to 130 (1300ms)
 
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