fractal said:
fixed! Well... turns out there is nothing wrong with it! At 100 volts, the throttle is so sensitive that even the slightest variation will cause it to jerk. What we need are better throttles for running 100+ volts. Maybe an Algorithm could be programmed in the firmware to make the throttle response smoother without scarificing fast accelelration. I'm sure somebody has already thought of that.
Worth remembering that an ebike speed control isn't a "throttle" and doesn't work like one. The throttle on a motorcycle or car pretty much directly controls the engine torque that's available, by restricting cylinder filling when closed or partially closed. When you open the throttle on a motorcycle the engine responds by producing more torque, so making it accelerate.
On an ebike, the throttle is typically a speed control, the position of the throttle is directly proportional to motor rpm, not motor torque. The reason for this is that it's the easy way to go as far as the controller is concerned, as throttle voltage can be linearly proportional to PWM duty cycle and hence applied motor voltage. The really big downside is that it means that the throttle has little or no direct control of motor torque. If you open the throttle then the controller goes flat out to get the motor up to the demanded speed. If you have a powerful set up this makes the throttle response seem a bit jerky, as you'll get far more torque than you want for an instant, often leading to you sub-conciously backing the throttle of a bit an instant later and then getting less torque than you want.
The real answer is to have a throttle control that is directly proportional to motor torque. This feels a lot better and is a lot smoother, as it stops the big jumps in motor torque as the controller tries to match demanded speed with actual speed. Unfortunately few controllers are able to do this, certainly none of the budget ebike controllers have a torque controlling throttle, AFAIK. It is possible to build an add-on that measures controller current and uses this as feedback to get a throttle that is proportional to power. This is almost as good as a throttle that's proportional to torque, in terms of feel, but doesn't need motor phase current monitoring.