115V 20A bike still running fast...

... however there is a unsolved problem.

At low speed (0 to 25-30Kph) the acceleration is hard to control. A slight touch of throttle and the motor revs up too quickly, while amps jump to high values.
In other words, at low speed the motor does not respond in a predictable way to throttle twist. It behaves almost like a on-off switch.

While reading some of your posts, I learned that a capacitor on the controller board regulates the ramp up acceleration; it should be the 10uF cap, located close to one end of the big 3.3k resistor.

I would think to replace this capacitor with a higher capacity one in order to smoothen those sudden amps peaks, regardless if the bike acceleration gets a bit lower.
I realize my question seems rather odd, as most people on the contrary wants to REDUCE its capacity in order to speed up more quickly.
Actually, my main goal is cutting amps peaks to not overload that weak 20A controller, and even if the bike loses some speed up capacity, I don't mind much. I can count on a high 60kph speed, which makes me happy.

Do you believe a higher capacity (20uF) could flatten the ramp up slope, thus providing the final solution to my problem?
Or else, which capacity should be suitable to begin with my initial trials?

Any suggestion will be greatly appreciated.

Antonio Zanardo

Do you mean this 10uF cap?

If so. Then try 22uF or 33 uF that you like.

Another thing that can make the throttle twitchy is if the full mechanical range of the throttle is not used. I had this problem on my scooter. I would have to turn the throttle almost half way before the motor started. All the control was left in the remaining half, which made it very sensitive.

To correct this, I placed a 150 ohm trimmer pot in series with the throttle (-) power wire. Then I could adjust the pot so there was only a slight amount of travel before the motor started.

You need to have some dead space at the end to compensate for temperature drift otherwise on a hot day, your motor might start creeping with no throttle.

fechter said:

Another thing that can make the throttle twitchy is if the full mechanical range of the throttle is not used. I had this problem on my scooter. I would have to turn the throttle almost half way before the motor started. All the control was left in the remaining half, which made it very sensitive.

To correct this, I placed a 150 ohm trimmer pot in series with the throttle (-) power wire. Then I could adjust the pot so there was only a slight amount of travel before the motor started.

You need to have some dead space at the end to compensate for temperature drift otherwise on a hot day, your motor might start creeping with no throttle.

Click to expand...

Do you install it in your ebike as well?

I may try your suggestion in my ebike.
Don't tihink the creeping is any concern if the brake has cut-off feature.

The7 said:

Do you install it in your ebike as well?

I may try your suggestion in my ebike.
Don't tihink the creeping is any concern if the brake has cut-off feature.

Click to expand...

My ebike is still under construction (very slowly).
It works great on my scooter though. I'm using a Crystalyte controller.