Bafang BBS02 resistance

[AHicks]

And yet plenty of people are saying they have high resistance on their bafang motors.

I've never heard of anything like that. Please reference....

And please, lets keep this conversation relevant to the Bafang BBSxx motors only.

 

[rccarguy]

I've never heard of anything like that. Please reference....

And please, lets keep this conversation relevant to the Bafang BBSxx motors only.

Are you a mod? If you don't like it, leave.

I have Bafang BBS02.
Google search brings up plenty of references to high resistance on BBS02/HD motors. No particular fixes.

 

[AHicks]

Are you a mod? If you don't like it, leave.

I have Bafang BBS02.
Google search brings up plenty of references to high resistance on BBS02/HD motors. No particular fixes.

Done....

 

[rccarguy]

So what is the solution? It's like going up a steep hill

 

[PedalUma]

I had a bike with resistance. It is a real thing, not to be brushed off lightly. The left crank arm square tapper was too wide and rubbing on the bb shell.

 

[rccarguy]

I had a bike with resistance. It is a real thing, not to be brushed off lightly. The left crank arm square tapper was too wide and rubbing on the bb shell.

Can you draw/explain that a bit more
Square taper ? Where the crank slots on?

 

[rccarguy]

Why is this forum filled with sanctimonious unhelpful **********

 

[rccarguy]

That for one, is basic nomenclature. There’s nothing sanctimonious to expect someone trying to solve an relying only on internet blather without the most basic understanding and command of the nomenclature.

We’ll help but you need to review some BBSHD tech drawings and motor nomenclature.

Where are you seeing resistance. Pedaling without battery power?

Yes. It's not too bad in the stand pedalling the crank turning the wheel, so not much load. You can turn the crank with pinkie finger.

But riding on the bike the amount of resistance is nuts, I'd say roughly 30% of my leg power just to turn it to ride the bike

 

[tomjasz]

Yes. It's not too bad in the stand pedalling the crank turning the wheel, so not much load. You can turn the crank with pinkie finger.

But riding on the bike the amount of resistance is nuts, I'd say roughly 30% of my leg power just to turn it to ride the bike

What’s your PAS setting?

 

[rccarguy]

L

What’s your PAS setting?

0..with the battery off.

What the high amount of resistance means is that I do not provide any assistance, as any of my pedal power is converted into resistance not power that is transmitted to the rear wheel

 

[tomjasz]

OFFS. Use your motor.

 

[rccarguy]

OFFS. Use your motor

So you're saying the bike is useless unless I have power?

When I run of our charge I had five miles to ride it was torture

One thing I've noticed is if pedal faster the motor is rotating I feel resistance.

 

[tomjasz]

ALL motors have power off resistance. And you ride a powerful motor designed for higher speeds. Want low resistance buy a 350W. Be glad you aren’t ridding a hub drive. Plan you rides better or add a bigger battery.

 

[EMGX]

Sorry if this has already been addressed or isn't a possibility for your unit. I only read your first couple posts and this page.
The video you posted on page one shows what looks to me to be normal appearing rotation in both directions but you aren't loading the pedals.
Is it possible that there is a problem with the clutch bearing or an internal alignment problem that causes it to lock up when you are applying force, as in pedaling?
Here is a video of a M600, not your motor, I know, but maybe the principle is the same?
Just a thought. You're a bike tech, so just take it apart and check the internals out. You won't be out anything as you got your money back anyway.

 

[EMGX]

Take the following for what it is worth, maybe nothing.
My Tongsheng has two one way bearings:
A sprag clutch that engages the axle to the main gear, if bafang is similar that one would be OK on your bike because it does spin the chainring and you have what you describe as resistance against the motor.
Another one way bearing that drives the reduction gear. That one is set into a nylon gear that meshes with the motor output shaft. That is the one which possibly is causing your problems (?)
This one way bearing is the one that prevents your pedaling from having to turn the motor, at least that is my impression.
This is the bafang version

Although it seems strange that it doesn't locked up at all when you turn your cranks on a stand, maybe just a defective gear/bearing that isn't aligned properly or just locks up when more force is applied. In any case it should be easy to remove and check, at least it is on the tongsheng where it is on the left side of the motor.
Cheap part.

But I'd check the entire gearing including the sprag clutch for function. I've had my Tongheng apart and if the bafang is similar it is a very simple process.

 

[AHicks]

Sorry if this has already been addressed or isn't a possibility for your unit. I only read your first couple posts and this page.
The video you posted on page one shows what looks to me to be normal appearing rotation in both directions but you aren't loading the pedals.
Is it possible that there is a problem with the clutch bearing or an internal alignment problem that causes it to lock up when you are applying force, as in pedaling?
Here is a video of a M600, not your motor, I know, but maybe the principle is the same?
Just a thought. You're a bike tech, so just take it apart and check the internals out. You won't be out anything as you got your money back anyway.

The only way he's going to know that, or check, is to get his hands dirty. That doesn't seem to be an option here....

 

[EMGX]

The only way he's going to know that, or check, is to get his hands dirty. That doesn't seem to be an option here....

Strange that he stated he is a "bike tech" if he doesn't want to crack it open and see what's up. Some of what he says doesn't seem to add up, but whatever, time to move on.

 

[rccarguy]

Jesus what a bunch of assholes

 

[tomjasz]

This has to be one of the most convoluted threads ever on EBR. Trying to fix normal motor drag so an eBike pedals like an acoustic bike. And we all fell for it, hook, line, and sinker.

 

[EMGX]

This has to be one of the most convoluted threads ever on EBR. Trying to fix normal motor drag so an eBike pedals like an acoustic bike. And we all fell for it, hook, line, and sinker.

I've never seen or ridden a bafang mid drive. If it is like the tongsheng with the one way bearings there shouldn't be any motor drag, should there? When pedaling with the motor off or faster than the motor is running assist the one way bearing in the nylon gear that runs the reduction gear disengages the motor, is that not correct? In that case the only added drag would be due to bearing and gear friction which is certainly more than a simple bottom bracket cartridge (as seen in the posted videos) but not excessive, and as he describes, unless there is some unusual bearing or gear problem that only manifests when pedaling under load. Added weight of the motor and battery definitely makes a difference to me but to OP discounts that.