To define the difference between an electrically assisted pedal cycle (EAPC) and an electrically powered motorbike  that is a bike which can be powered solely be an electric motor  the EU specified a speed limit of 15.5mph (25kph) before the motor cuts out and no assistance is given. If you exceed this speed when cycling, the motor will cut out.Most riders will normally cycle at around this speed, and as the sensors are sensitive to speed changes, it may give the impression of an intermittent fault with the motor as you go above and below this speed.