Brand New BBS02B...PAS not working

[RobAV]

Hi, I've just spent the weekend building up a Scott mtb with a BBS02b...but when it came to the first test ride...the PAS does not work..but the throttle does. I don't ride using the throttle..I only installed the throttle to check there was power whilst on the work stand!
I've double checked all the connections, triple if not quadruple checked the wheel sensor for its gap right down to 1mm..the sensor lights up as the magnet passes (as it should) but still no PAS. All the parameters in the display are fine, no error codes. I've disconnected the throttle and brakes...and still no PAS.
All the wiring is perfect etc (I built my road BBS01b a few months ago, which is great) so its not like its my first build. This is a brand new BBS02b with zero miles which I only received on Friday (October 1st). Any ideas or do I disassemble the BBS kit and send the lot back and ask for a refund (which would be a huge shame)?

Help and advice appreciated!

 

[wheeliepete]

Do you have a programming cable? If so, you could check the settings. Sellers often change them and they could have done something wrong, although there is no way to disable the PAS in there. You could also remove the 3 controller allen key bolts and check the PAS sensor plug is properly connected, it's the black 4 wire one. Otherwise it's likely to be a duff sensor or broken magnetic disc in which case it's best to contact the seller.

 

[RobAV]

Do you have a programming cable? If so, you could check the settings. Sellers often change them and they could have done something wrong, although there is no way to disable the PAS in there. You could also remove the 3 controller allen key bolts and check the PAS sensor plug is properly connected, it's the black 4 wire one. Otherwise it's likely to be a duff sensor or broken magnetic disc in which case it's best to contact the seller.

Thanks for replying. Yes I have a programming cable and all the parameters are fine (I checked....twice...carefully). I've never opened a motor up tho, which side of the motor does the PAS sensor plug fit, chain side, under the drive gearing? Any chance of a pic so I know what to look for?

 

[MontyPAS]

Thanks for replying. Yes I have a programming cable and all the parameters are fine (I checked....twice...carefully). I've never opened a motor up tho, which side of the motor does the PAS sensor plug fit, chain side, under the drive gearing? Any chance of a pic so I know what to look for?

Had a similar issue a while back.
Try swapping the display from your working bike!
Mine proved to be a duffer! Worth a try to eliminate?

 

[RobAV]

Had a similar issue a while back.
Try swapping the display from your working bike!
Mine proved to be a duffer! Worth a try to eliminate?

Good idea, I'll try the display and the wheel sensor off the other bike (BBS01B) tomorrow. If that doesn't work its definitely an internal issue.

 

[wheeliepete]

It's in the controller casing in front of the chainwheel, it does come off with the chainwheel in place, but easier with it removed. Just remove the 3 allen key bolts you see in the photo.

 

[RobAV]

It's in the controller casing in front of the chainwheel, it does come off with the chainwheel in place, but easier with it removed. Just remove the 3 allen key bolts you see in the photo.

View attachment 44276

Cheers for that....I'll swap the display and wheel sensor first...then take a peek under that cover if that doesn't point to whats wrong...can it be removed with the motor in the frames BB...or does the motor have to come out?

 

[wheeliepete]

Cheers for that....I'll swap the display and wheel sensor first...then take a peek under that cover if that doesn't point to whats wrong...can it be removed with the motor in the frames BB...or does the motor have to come out?

Agree, start with the easy stuff. Yes, no need to remove motor from frame.

 

[RobAV]

Well I swapped the display from the BBS01b onto the BBS02b....that didn't work. I then swapped the wheel sensor....still nothing. I opened up the cover (after removing the crank arm, sprocket and drive cover.....the drive cover on my BBS02B blocks removal of the controller cover) and noticed the black connector wasn't firmly home, sitting at an angle. I duly opened the connector checked the pins where OK, re-assembled the connector making sure it was fully home, checked to see if anything else was loose (all OK) re-assembled the lot.....and nothing. Same as before the motor only spins up on the throttle!

Luckily for me the ebay seller (treek-motor)accepts returns and postage free! So I then spent two hours dis-assembling the entire kit and re-packing the box (I hadn't thrown the original packaging away....phew!), so now its all packed up (a royal pain in the backside) with a printed pre-paid return label and I'm off to the Post Office to send it back to the return address in Leicester.

 

[wheeliepete]

Well I swapped the display from the BBS01b onto the BBS02b....that didn't work. I then swapped the wheel sensor....still nothing. I opened up the cover (after removing the crank arm, sprocket and drive cover.....the drive cover on my BBS02B blocks removal of the controller cover) and noticed the black connector wasn't firmly home, sitting at an angle. I duly opened the connector checked the pins where OK, re-assembled the connector making sure it was fully home, checked to see if anything else was loose (all OK) re-assembled the lot.....and nothing. Same as before the motor only spins up on the throttle!

Luckily for me the ebay seller (treek-motor)accepts returns and postage free! So I then spent two hours dis-assembling the entire kit and re-packing the box (I hadn't thrown the original packaging away....phew!), so now its all packed up (a royal pain in the backside) with a printed pre-paid return label and I'm off to the Post Office to send it back to the return address in Leicester.

Bugger! thought you were onto something reading your post, at least your seller has a UK return address, hope they sort it out for you.

 

[RobAV]

Bugger! thought you were onto something reading your post, at least your seller has a UK return address, hope they sort it out for you.

Yeh me too, as my Scott is now un-rideable as I'm not re-installing the original Shimano crank only to take it out yet again when I get a working BBS02B...and my legs are flamin' killing me from all the kneeling down over the last couple of days.. think I've stretched the muscles or tendons.

 

[Andy230262]

When I assembled my bike with the BBs02 mine did the same . No power. My son in law checked all the connections and there was a little spark from the main Batt connector and it was working. Have no idea what happened . Been great since then .

 

[RobAV]

It lives! I received a refund last Saturday (from eBay) and ordered another Bbs02b from the same supplier (treek-motor) on Wednesday (I made sure I actually had the money in PayPal) and it arrived yesterday.l
No problems with the new BBS, and I must congratulate eBay and treek- motor for their no cost return and 3 day refund policy, worth its weight in gold! I asked them to just swap it, but you have to get the refund first then re-order.
Anyway, as I said this one works great, the jump in torque from my BBS01b is like night and day, I was smiling like a Cheshire cat riding this on a local private lane. I've not installed the throttle, as I don't use them (get a moped if you're a throttle guy IMO) and not too bothered about speed, it's hills or valleys off-road here in Derbyshire and thats where the extra torque is really felt.
Must ask about our rubbish UK laws, my BBS01B is great for town or flattish riding and I'll still be using it but the lack of torque going up steep hills with an artic up your backside is flamin' illogical and dangerous, why not allow 750watt motors but keep the speed limit the same?

 

[guerney]

Must ask about our rubbish UK laws, my BBS01B is great for town or flattish riding and I'll still be using it but the lack of torque going up steep hills with an artic up your backside is flamin' illogical and dangerous,

When my new controller arrives in about two weeks, I'll be using it at 25A (or 20A, if 25A is not available) on my BBS01b - 25A is the max continuous current that my battery can provide (according to the battery seller)... should give hillclimbing grunt, legally. Have been using it at 15A, which was pretty good anyway (but slow) on the local steepest hills.

 

[RobAV]

When my new controller arrives in about two weeks, I'll be using it at 25A (or 20A, if 25A is not available) on my BBS01b - 25A is the max continuous current that my battery can provide (according to the battery seller)... should give hillclimbing grunt, legally. Have been using it at 15A, which was pretty good anyway (but slow) on the local steepest hills.

I had my 01B set at 18amp and 100%/100% PAS level 9 and 100% keep current for a max of 720w at 40v (42v fully charged minus 2v bat sag) ...good but just as you said above still slow uphill, although fully capable of climbing its sub 10mph up steep gradients of 12% plus. On flatish ground, woohoo, the 01b flies when I lift the legal limit when away from the main roads. The prob with the Bafang controllers if using PAS (which I do) is if you're not accelerating (like going up a steep incline), it presumes your cruising and drops the wattage......

 

[guerney]

The prob with the Bafang controllers if using PAS (which I do) is if you're not accelerating (like going up a steep incline), it presumes your cruising and drops the wattage......

Are you sure about this? I've never noticed that happening, but will try to check... in about 2 weeks.

 

[guerney]

I had my 01B set at 18amp and 100%/100% PAS level 9 and 100% keep current for a max of 720w at 40v

I've only ever had mine at 80% keep current, 100% assistance PAS Level 9 - but bare motors are available from greenbikekit.com, so I'm no longer nervous of burning one out.

 

[RobAV]

I've only ever had mine at 80% keep current, 100% assistance PAS Level 9 - but bare motors are available from greenbikekit.com, so I'm no longer nervous of burning one out. Is the 720w a reading on your display, or a calculation?

On the display, it's not running out of cadence (approx 80-85rpm) it's the controllers presuming your cruising so dropping the watts ( amps in reality) as it's not detecting your accelerating, so it gives enough power to maintain the speed it THINKS you need. By the way, at 15amp 80% keep current is only a max of 12amp (40v x 12a = 480w...so many people get this setting wrong, they read those old US threads, keep current is a safeguard setting related to to the Limit Current setting on the Basic tab...it's this setting that all the PAS levels read from, not the Limit Current setting. Limit Current is the max allowed into the windings, Keep Current is the percentage of that current to use, the PAS levels are values of Keep Current. HTH.

 

[guerney]

On the display, it's not running out of cadence (approx 80-85rpm) it's the controllers presuming your cruising so dropping the watts ( amps in reality) as it's not detecting your accelerating, so it gives enough power to maintain the speed it THINKS you need

I've never noticed that happening - are you sure it isn't caused by voltage sag and a smaller capacity battery? I've got a 19.2ah battery made out of LG cells of some sort, might sag less rapidly than a smaller capacity battery would? The only thing limiting my bike (when unrestricted) is it's gearing, which is why I may install a 60T chainwheel or greater, if I can operate at 25A - then I'd still be able to tackle hills at about the same speed as I do now, but the flats would be far blurrier. (occasionally).

Alligt chainwheel 60 BCD (Bafang Motor)

 

[RobAV]

Not voltage sag, it's the controller thinking your cruising when in PAS ( different in throttle mode, that's user on demand), mines a 17.5ah Samsung bat and drops about 2v when maxed (then rises when backed off) .
Same problem here a 40t is great for hills (but slow), a 44t is a good medium (I have both), but a 50t or more would be great for flatter terrain cycling. .the problem is the lack of torque from the BBS01B, raising the chainring size will put undue heat into the motor on inclines, drawing loads of amps but unable to accelerate or maintain a constant, so producing excess heat...and then something will break/ burn out.