Bafang BBSxx - fault finding and fixes

[luterra]

An update to my issues...

Problem recurred in a few days after tightening wiring, so that was ultimately not the cause. I took a multimeter to it when it was acting up. Voltage from the battery showed 51.8 but dropped to around 20 when connected to the motor, with almost no current flowing so not a short circuit. Voltage would slowly rise as capacitor charged, then would tank (with rapid display shutdown) when I tried to turn it on. I'm about 90% certain this is a battery/BMS problem rather than a BBS02 problem. I did notice that it only happened if I left the BBS02 connected to the battery when not in use (even for only a few hours). Since then have been disconnecting between commutes and has been working well.

 

[bono]

Hi Guys,

I think that I have another problem with my BB02 (I needed to change the controller, then there was a strange noise coming from the motor https://www.youtube.com/watch?v=VV7UvRi6bAc, the motor was sent two times for a repair…). Now I have noticed this noise coming from the motor when pedaling without using the throttle.

https://youtu.be/e-qjojAQPzM

Is this something normal and I am too paranoid or this is something wrong with the motor?

Thanks!

 

[Teh Stork]

Symptom: Creaking / noise coming from crank/motor area when pedaling. Only creaking when putting weight on left pedal.

Throttle only: no noise.
Noise is synchronous with pedaling. Chainwheel/chain not at fault.
Freewheels as it should
BBS02 750W @500W
Milage: 400 km - with hard use in urban areas.

Tried tightening the screw holding the "crank-innards-assembly", did not alleviate the issue.

 

[alfantastic]

Symptom: Creaking / noise coming from crank/motor area when pedaling. Only creaking when putting weight on left pedal.

Throttle only: no noise.
Noise is synchronous with pedaling. Chainwheel/chain not at fault.
Freewheels as it should
BBS02 750W @500W
Milage: 400 km - with hard use in urban areas.

Tried tightening the screw holding the "crank-innards-assembly", did not alleviate the issue.

RU tightening the crank bolt using just one of those generic tool kit hex keys, or are you using a torque wrench?

I tighten both my crank bolts to 35Nm, which is actually a lot tighter, than you would tighten guessing by hand.

 

[ginekolog]

Hi Guys,
https://youtu.be/e-qjojAQPzM
Is this something normal and I am too paranoid or this is something wrong with the motor?

Thanks!

My first post on this interesting community.. hi all

I have similar noise as you when pedaling. With motor power is quiet. It was quiet on begining also when pedaling. I took unit apart and found reason for noise: small metal gear( that is driving big gear ) looked fine on sight but when I tocuhed it found problem. Edges of gear teeth are sharp and worn. Thats why gears make noise because when you pedal faster than motor, other side of gear teeth touch and make noise. Grease was good in all areas.

This gear is failing:
http://www.greenbikekit.com/accessories/bafang-8fun-spare-parts/bafang-8fun-mid-crank-kit-bbs01-bbs02-iron-gear-replacement.html

I have unit 4 months with 1000km, its dated 2014-10. I ride it hard offroad, big uphills with 30% grades and on somtimes on full power . My dealer said that gears are not coverd by warranty and are considered consumption material . It seems to me unit is not designed to withstand full power for too long time.

I love riding it, it gives me superb climbing power + 52 km/h on flats. GREAT fun, bike is only 22kg. But i did not think it would worn out so fast.

For now I will not change gear.. thinking gears will adapt to eachother and wear will stop. Is it possible? If not, I will change it.. from link above it seems bafang made version2 of gear.

 

[Teh Stork]

Symptom: Creaking / noise coming from crank/motor area when pedaling. Only creaking when putting weight on left pedal.

Throttle only: no noise.
Noise is synchronous with pedaling. Chainwheel/chain not at fault.
Freewheels as it should
BBS02 750W @500W
Milage: 400 km - with hard use in urban areas.

Tried tightening the screw holding the "crank-innards-assembly", did not alleviate the issue.

RU tightening the crank bolt using just one of those generic tool kit hex keys, or are you using a torque wrench?

I tighten both my crank bolts to 35Nm, which is actually a lot tighter, than you would tighten guessing by hand.

Do you think this creaking is coming from a loose pedal-arm? I tighten these good, but not at 35Nm.

 

[bono]

Thank you very much for this info! I am disappointed with the reliability of the motor. I am using this motor for commuting, the bike has never been off the beaten track - flat terrain, express way, not many stops, 26 miles each day... after previous failure I am riding less than 25 mph...

Hi Guys,
https://youtu.be/e-qjojAQPzM
Is this something normal and I am too paranoid or this is something wrong with the motor?

Thanks!

My first post on this interesting community.. hi all

I have similar noise as you when pedaling. With motor power is quiet. It was quiet on begining also when pedaling. I took unit apart and found reason for noise: small metal gear( that is driving big gear ) looked fine on sight but when I tocuhed it found problem. Edges of gear teeth are sharp and worn. Thats why gears make noise because when you pedal faster than motor, other side of gear teeth touch and make noise. Grease was good in all areas.

This gear is failing:
http://www.greenbikekit.com/accessories/bafang-8fun-spare-parts/bafang-8fun-mid-crank-kit-bbs01-bbs02-iron-gear-replacement.html

I have unit 4 months with 1000km, its dated 2014-10. I ride it hard offroad, big uphills with 30% grades and on somtimes on full power . My dealer said that gears are not coverd by warranty and are considered consumption material . It seems to me unit is not designed to withstand full power for too long time.

I love riding it, it gives me superb climbing power + 52 km/h on flats. GREAT fun, bike is only 22kg. But i did not think it would worn out so fast.

For now I will not change gear.. thinking gears will adapt to eachother and wear will stop. Is it possible? If not, I will change it.. from link above it seems bafang made version2 of gear.

 

[alfantastic]

Symptom: Creaking / noise coming from crank/motor area when pedaling. Only creaking when putting weight on left pedal.

Throttle only: no noise.
Noise is synchronous with pedaling. Chainwheel/chain not at fault.
Freewheels as it should
BBS02 750W @500W
Milage: 400 km - with hard use in urban areas.

Tried tightening the screw holding the "crank-innards-assembly", did not alleviate the issue.

RU tightening the crank bolt using just one of those generic tool kit hex keys, or are you using a torque wrench?

I tighten both my crank bolts to 35Nm, which is actually a lot tighter, than you would tighten guessing by hand.

Do you think this creaking is coming from a loose pedal-arm? I tighten these good, but not at 35Nm.

It could well be, if you are not tightening the crank bolt enough.

I always tighten major assemblies using a torque wrench and the correct torque setting. Correctly torquing is not only for safety, but ensures longevity of the connected parts.

This link from Park Tools is a good reference point: http://www.parktool.com/uploads/files/blog/torque.pdf

 

[Teh Stork]

Edit: Tightened the crank arm bolt very tightly and thought that the sound dissappeared - but no, it did not. Still makes the original creaking sound.

 

[alfantastic]

Edit: Tightened the crank arm bolt very tightly and thought that the sound dissappeared - but no, it did not. Still makes the original creaking sound.

Are you sure it's not your left knee creaking :lol:

 

[Teh Stork]

Hehe, absolutely.

I've become quite strong in my legs, and I wonder if I might have damaged the bearings by some jumping + hard pedaling. (not overweight, ~70kg) Still, I only have 400 km so far on the motor. If the creaking becomes worse or stops or I find the solution - I'll be sure to update here.

 

[speedmd]

Most likely the crank riding it! :lol: Is it loose in the bb? Pedals loose or need grease? Gear box side of the BB sometimes will not seat well on some frames and leave a space for it to rock around a bit. I had to use a thin spacer on mine to get it to lock up good and square. If nothing else works, I use soft loctite or a bunch of teflon tape at the interfaces which usually shuts it up reasonably well.

 

[Teh Stork]

Yeah, that and oil impregnated paper (thausvedt here on ES reccomended this) definitely helps to eliminate play. Fixed a different bike with this method. I used locktite between the plate that holds the motor and the frame, but I will try to re-fasten the locknuts tomorrow.

 

[tomjasz]

Thank you very much for this info! I am disappointed with the reliability of the motor. I am using this motor for commuting, the bike has never been off the beaten track - flat terrain, express way, not many stops, 26 miles each day... after previous failure I am riding less than 25 mph...

Bono, what were the failures?
How many total miles?

I'm sorry to read that it's been a difficult experience. If I can help in any way lease don't hesitate!

 

[bono]

At the beginning em3ev asked me to swap the controller. Great that it happened before the old one failed, but still I understand there was something wrong with the coding. Not sure if this was distributor fault, but anyway, a problem.

I had this noise around 1200-1400 miles, do not remember exactly.

https://www.youtube.com/watch?v=VV7UvRi6bAc

Sent the motor for a repair, got it back, but still there was something wrong - different kind of noise. Sent it back.

Now I have around 1850 miles on the motor and hear this noise

https://youtu.be/e-qjojAQPzM

I would expect that this unit is more reliable. Is there anything like replacement policy under the Bafang warranty policy?

Thank you very much for this info! I am disappointed with the reliability of the motor. I am using this motor for commuting, the bike has never been off the beaten track - flat terrain, express way, not many stops, 26 miles each day... after previous failure I am riding less than 25 mph...

Bono, what were the failures?
How many total miles?

I'm sorry to read that it's been a difficult experience. If I can help in any way lease don't hesitate!

 

[tomjasz]

I don't know. I do know that Bafang is notoriously bad at communicating, but some have had success. At least anecdotally. I'd sure give it a whirl.
Yours is one of the horror stories from my view. I'd think with good documentation there would be a response. Certainly worth a try. What does Paul say about a replacement? I'd certainly make a pitch for a new complete motor assembly.

 

[tomjasz]

Warranty period starts from the date of leaving factory, and is 30 months for motor, and 18 months for controller, display, sensor and other components. Bafang limited warranty does not cover or apply to the following situations:
1) Damage, failure and/or loss caused by refitting, neglect, improper maintenance, accident, misuse, abuse or use for competition or commercial purpose;
2) Damage, failure and/or loss due to shipping;
3) Damage, failure and/or loss caused by improper installation, adjustment or repairing.
4) Damage, failure and/or loss irrelevant to material and workmanship, e.g., failure to follow instructions by users；
5) Damage, failure and/or loss caused by product’s appearance or surface change which doesn’t affect its function.
6) Damage, failure and/or loss caused by unauthorized service or installation；
7) Damage, failure or loss caused by normal wear and tear.
Bafang reserves the right to repair or replace the components, and is only responsible for repairing or replacing them.

In case bike manufacturers or dealers encounter quality issues when using or selling Bafang's products, they can report the purchase order number and products’ serial number to Bafang's technology service department who will check whether the products are under warranty or not. For products under warranty, if it is a small problem, Bafang will provide customers (dealers or bike manufacturers) with free spare parts so that they can correct the problem themselves; if it's a big issue, Bafang will provide customers with free spare parts, show them what to do by sending them videos or documents or on some special occasions repairing the products for them. For products out of warranty, Bafang can still provide spare parts or repair the products for customers, but the incurred material cost, labor cost, freight etc. shall be undertaken by customers.

If an end user has a bike equipped with Bafang components which need repairing, he/she should contact the bike manufacturer or dealer directly.

If this warranty statement is against a current Chinese law, the Chinese law shall prevail. Bafang reserves the right to modify the terms without announcement in advance.

 

[bono]

Thanks, I have seen this on the website. I asked Paul about replacement, but he did not response yet. I will report back when I hear from him. Thank you!

 

[puregsr]

It took me a while to skim through 20 pages of information here.

My experience with a BBS02 (2014/12) with about 150 miles. I noticed there was this rubbing squeaking noise while pedaling when motor is off such as during low speed pedaling or during shifting. Once the motor was running, the noise went away. Almost sounded like a squeaking belt on a car.

I opened the motor and inspected it but didn't really notice anything grossly wrong. I didn't really take it apart completely. I tried to spin the small iron gear and it reproduced the noise. I just added a little grease to it, slapped it back together and it seems to be fine so far. I'm not sure if the grease did anything to it or the mere fact of opening it up did anything to it.

I did have problem of the locking nut/ring worked their way loose many times. Adding copious amount of blue threadlocker made it so difficult to remove them that I didn't do it when I reassembled it this time, expecting that I may have to do it again.

I really want this kit to work and so far I am satisfied with it, but for the amount of money I paid over my direct drive hub motor, I really want it to be flawless.

Would somebody make a video on pepper teardown and overhaul of this unit?

 

[DaDo.Bzz]

I found one, who can find it? )) Was a big crash, hit cutted tree in 30kmh!

 

[Samd]

I've had a few customers in Australia not tightening their left crank arm properly. Same as a regular bike, after a few hundred km's the crank's inner square surface gets damaged.

Pull them off and you'll see the damage.

I have several spare arms if needed.

 

[alfantastic]

I've had a few customers in Australia not tightening their left crank arm properly. Same as a regular bike, after a few hundred km's the crank's inner square surface gets damaged.

Pull them off and you'll see the damage.

I have several spare arms if needed.

Do you have an official torque wrench setting that we should be tightening the crank bolt to?

 

[Tamaz]

So i just got this problem on my kit, but its not only when moving the pedals. The same symptom apears when riding along by throttle if there is a lot of resistance. I suspect its the one-way bearing that is inside the plastic gear that slips. I have ordered a new one to replace it.
https://www.youtube.com/watch?v=4X3RCYICcSQ

BBS02 48V 750W
1405141880

 

[bono]

I got response from em3ev. Paul suggested that I send the kit to China and he would refund costs of the part only. I will pass and I will contact Bafang directly. I do not count on much, but I will just share my regrets.

Thanks, I have seen this on the website. I asked Paul about replacement, but he did not response yet. I will report back when I hear from him. Thank you!

 

[tomjasz]

I got response from em3ev. Paul suggested that I send the kit to China and he would refund costs of the part only. I will pass and I will contact Bafang directly. I do not count on much, but I will just share my regrets.

Thanks, I have seen this on the website. I asked Paul about replacement, but he did not response yet. I will report back when I hear from him. Thank you!

Given the history I'd remind Paul of the problems and list the history for him. I'd personally call bullshit on this one. From my view he needs to stand tall and make the good with a new motor. This is VERY disappointing... This is the service I'd expect from a discounter, not a premium reseller like EM3ev.