Abstract: Herein described is a bicycle comprising a frame, a drive wheel and a pedal crank/pedal assembly which transmits mechanical energy to the drive wheel by means of a transmission system which comprises: a tank containing a hydraulic fluid; a hydraulic circuit in which the hydraulic fluid flows; a hydraulic pump, actuated by the pedal crank/pedal assembly and configured to pump the hydraulic fluid through the hydraulic circuit; at least one hydraulic actuator, arranged along the hydraulic circuit and configured to transform the hydraulic energy supplied by the hydraulic pump to the hydraulic fluid into mechanical energy; and a drive shaft, connected to the hydraulic actuator and configured to transfer the mechanical energy generated by the hydraulic actuator to the drive wheel. The hydraulic pump is connected to an electric motor whose rotational speed, as well as the operating parameters of the hydraulic pump, are controlled by a circuit board.

Abstract: Herein described is a gearmotor assembly for bicycles comprising a pedal crank shaft, an electric motor provided with an electronic control unit, a reduction gear mechanism and a gear wheel, arranged coaxially around the pedal crank shaft. The gearmotor assembly further comprises two internal overrunning clutches, mounted coaxially around the pedal crank shaft and configured to transmit torque in a first direction of rotation of the pedal crank shaft, and an external overrunning clutch, mounted coaxially inside the gear wheel and configured to transmit torque in a second direction of rotation of the pedal crank shaft which is opposite with respect to the first direction of rotation. A hollow tubular element kinematically connected to the drive wheel for transmitting the torque is interposed between the internal and external overrunning clutches.