Fixed gear hub motor w torque sensing bb for throttle?

[Hummina Shadeeba]

Is there a torque sensing bottom bracket that senses torque in both directions so could run my hub motor as a fixed gear and then can accelerate and do regen braking with the cranks?

 

[qwerkus]

Is there a torque sensing bottom bracket that senses torque in both directions so could run my hub motor as a fixed gear and then can accelerate and do regen braking with the cranks?

That's probably not a good idea, since it would involve removing the freewheel protecting the pedals ... and your feet. A sudden power surge in the DD hub motor could seriously hurt all the way up to knees and hips.
That being said, you don't need a fixed gear to do what you want. Torque sensors usually come with a quadrature pas signal that tracks cadence AND direction. You can use this to program a regen mode when pedaling backwards and even add a modulation to increase / decrease that regen by reverse pedaling slower or faster. IIRC grintech implemented this on all latest phaserunners and baserunners. Easy to do with a vesc also: i wrote a lispBM script for my CLWB - unfortunately the TQ sensor died and now I only have a PAS working.

 

[Hummina Shadeeba]

That's probably not a good idea, since it would involve removing the freewheel protecting the pedals ... and your feet. A sudden power surge in the DD hub motor could seriously hurt all the way up to knees and hips.
That being said, you don't need a fixed gear to do what you want. Torque sensors usually come with a quadrature pas signal that tracks cadence AND direction. You can use this to program a regen mode when pedaling backwards and even add a modulation to increase / decrease that regen by reverse pedaling slower or faster. IIRC grintech implemented this on all latest phaserunners and baserunners. Easy to do with a vesc also: i wrote a lispBM script for my CLWB - unfortunately the TQ sensor died and now I only have a

I’ll use a giant 74t chainring and will pedal at low rpm’s so I think no shocks sent up my legs.

Do u know what torque sensing bb would work in the way i was imagining with a fixed gear? I feel like if I use a freewheel it has no backpedaling resistance and will have less control. How does it do like that?


I used to ride a regular bike with a fixed gear and front brake. This would be that but with strong throttle n braking, essentially making it a motorcycle with no hand controls. I like that. I think it might be even safer, ..maybe.. if with short cranks. I want to try it regardless.

Surely been done but I can’t find a link. Any leads?



@Chalo
@amberwolf

 

[stancecoke]

Is there a torque sensing bottom bracket that senses torque in both directions

The Thun/NTCE has the idle signal at half of the output range, so it can measure the torque in both directions. But it can measure the torque only from the left crank.


The ERider models have the idle signal at 1.5V, so some headroom for negative torque also.
But I never tried, if the signal falls lower than 1.5V with negative torque.



Using the simple ADC input of the VESC will not lead to a satisfying assistance behaviour, you will have to calculate the setpoint for the motor current from the riders power, so the cadence has to be part of the calculation.

planning software / hardware for a controller-replacement (vesc)

Hi there, I got a very cheap Ampler ebike, with the following specs: 48V 13S2P Battery Q100C CST 36V350W Motor Both PAS & Torque sensor on board The issue: the original controller shorts out whenever the battery is connected. So, I'm replacing it with a Flipsky FESC 6.7 pro mini (VESC-based)...

endless-sphere.com

With a VESC you can achieve this by a LISP script, by direct implementation in the VESC code, or by an additional pre-controller