Controller for electric bicycle, power unit for electric bicycle, and electric bicycle

A controller (100) for an electric bicycle (1), which can generate assist torque by means of an electric motor (60), includes a control unit (105) that is adapted to supply power to the electric motor (60) in response to a signal output from a pedal torque detecting part (57) detecting torque input to the pedals (33, 34). The control unit (105) includes a smooth power generation part (111) that is adapted to generate power of which the period is longer than the period of the signal output from the pedal torque detecting part (57) and which is smoothed, and a boost power generation part (112) that is adapted to generate power, of which a variation per period of the signal output from the pedal torque detecting part (57) is larger than a variation of the smoothed power per period of the signal, in response to a parameter that is changed by a driver's operation when a boost is requested.