BBS02 Cutting Out

[2old]

I have a BBS02-equipped hardtail, coupled with a 52V, 14 ah battery that has been used for MTB during the past seven years and has performed perfectly with no maintenance or problems. Recently the PAS (no throttle) has started cutting out on occasion. It will always "restart" after a few seconds or minutes and not cut out again on the ride. Any ideas?

 

[Chalo]

When I dealt with that problem on a BBS02, it was due to the pedal sensor magnet ring inside the unit having broken. The fragments would occasionally shift and overlap, causing intermittent failures of the PAS.

I used neutral cure silicone to cement the pieces down in their original positions, and the problem went away.

 

[mickyd]

I actually had the same issue on my BBS02 mountain bike. I never troubleshot it since I also had a thumb throttle and realized over a short time that I preferred using the thumb throttle vs. pedal assist especially when mountain biking. It allows me to work as little or as hard as I'd like to.

You may consider that as an option should you find your magnetic ring is broke. If not, they are available through Luna Cycle.
https://lunacycle.com/bbshd-and-bbs02-replacement-pas-disc/

 

[tomjasz]

7 year old battery? Mine cut out from sag.

 

[2old]

Thank you for your comments. I don't think it's the battery since the battery is newer than the motor, and the bike might run perfectly for a long period after cutting out initially. The PAS ring seems like the culprit.

 

[tomjasz]

I guess I'm confused. The internal PAS and no error code? Odd in my experience...

 

[Chalo]

I guess I'm confused. The internal PAS and no error code? Odd in my experience...

With a busted magnet ring, the controller is still getting a signal; it's just an erroneous signal. There's nothing to make the controller generate an error.