Here's an easy mod that improves the low speed throttle response.
The throttle output is a nominal 1 volt at zero throttle and 4 volts at full throttle. The controller, however, does not begin to produce output until the throttle voltage reaches 1.4v or so. This makes it necessary to move the throttle almost half way before the motor starts, and makes the throttle extremely sensitive in the remaining travel.
Most hall throttles have a non-linear output curve that is more gradual at the low end. This is supposed to make the response more manageable, but since the controller has such a high starting threshold, the gradual part doesn't get used.
To correct this, you can install a trimmer pot in series with the negative power lead (black wire) of the throttle. I used a 200 ohm, 20 turn pot.
With the wheel off the ground, the pot is adjusted until the motor just starts to move, then backed off a turn or so to make sure the motor stops.
With my throttle, the resistance at the proper adjustment was around 100 ohms.
Here's a picutre of mine. Note: I'm using non-standard color coded wires.
