One of the way to overcome this is to change the riding style and start using the rear brakes like a clutch to control the surging. It helps when you are climbing steeps or over obstacles to modulate the torque.So I just finished building and riding my new Cheeb withM600 motor. I have owned a Shimano E8000 for several years and I am right now disappointed with the M600 by comparison. The M600 seems to provide too much power when I do not want it , and not enough when I do. The Shimano and a Bosch I tested today both seem to respond to my pressure input and deliver back some extra power when I really load up the system with pedal pressure and slow down the cadence a bit. The M600 seems to rely primarily on cadence to deliver its power, so I need to get in a very low gear at times to maintain high cadence and then when I clear the tough spot, the motor surges and provides too much. Is there a way to modify the programming to help deal with this issue?