The thumb throttle on the right hand handlebar is available to the rider at any time the bike is switched on. It over rides the pedal assist giving full power at a moments notice. This is useful for hill starts, in heavy traffic and when getting away from traffic lights. The rider can also have a rest from pedalling. Due to a change in the law on 6th April 2015, the throttle will run the motor up to 5KPH(3MPH) when the pedals are not being turned, and up to 25KPH (15MPH) when the pedals are rotating. However, any bike sold before the change of the law will run up to 25KPH (15MPH) on throttle at all times.