Bafang Ultra teardown of torque sensor assembly

[paxtana]

For reference

[tommie]

Hi Paxtana, just on the subject of the Ultra motor, does it have both torque and cadence?

And how noisy is it compared to the BBSHD as i understand they changed to steel gears recently?

I do like the way cadence PAS works in my BBSHD.

[ncmired]

I'd love to have a (non-fat tire) commuter bike with this motor, and have, like others, been sniffing around for frames. What about the chain line? Does the Bafang Max motor spline chain ring spider fit on the Ultra motor?

I'd hate to have to do what Rodriguez did with this build (probably a 55mm chainline, since it has a Rohloff):

Where do the Bafang Ultra build fans hang out? I get that nobody can market the Ultra on a road bike - market it as a trail bike, or as a frame / motor / whatever kit.

[Ivanovitch_k]

@paxtana

I'm trying to remove the gear & axle as you did.

I have removed the two snap rings using bent-nose pliers.

However I fail to see how to continue. Is there something else to unscrew like with the special 4-teeth tool on the BBS series ?

I tried to hammer the axle one way or another but it wouldn't buldge :?

Thx for the help !


edit:

found a way to do it.

Attach the chainring spider to get a good grip and pull out.

It might be hard at first, I pulled a bit on one arm of the spider, then onto the next one in a circle fashion and it eventually came out.

Once extracted, you get direct access to the clutch mechanism & needle/thrust bearing. They look fairly similar to the bbshd ones.

[ncmired]

Hi Robert - I've come across a few Bafang Ultra frames via Alibaba as well, but all the interesting ones are not sold single unit quantities. I'm not in a financial position to swing a custom Ultra frame / build, so I'm sitting on the sidelines for now. Plus, I'm a little worried about the Ultra motor product lifespan, and leery about speeding big dollars on a bike constrained to a potentially short span motor availability.

Who knows, isn't it about time for a Bafang BBS04 motor ;-), or at the very least, a standard defined for the motor hanger.

[Ivanovitch_k]

the freys are 2000-4000$ with shipping to eu/na depending on configuration (higher end can come with sram ex1 & 52V reention downtube integrated batteries).
see ES thread.

there is also Excess bikes, a german-made carbon fiber frame with the ultra. FLX bikes got an Al one too. And, of course, luna with the apex.

IIRC someone over at ES also got a made to order titanium FS frame too.

[fambo1]

has anyone had success programming ultra motors.not sure if i need to but have a new bike .seems like power is not constant when pedaling up hill . read that other folks have similar issues

[badrab]

I've found the easiest way is to get an Eggrider V2 for about $100. It's plug and play with the Ultra motor and you can easily program all parameters using an iPhone or Android via bluetooth:

https://eggbikes.com/eggrider?tag=bafang

More here also:

https://electricbike.com/forum/forum/builds/custom-ebike-motor-programming/71853-bafang-ultra-drive-programming

--pete

[h-ergaster]

I came across this article as I was researching a problem at work before I retired, it can help to de-mystify torque sensors.

https://www.motioncontroltips.com/wh...iKTvwl1GWwrYq0