A power unit for a pedal vehicle includes a pedal shaft, an output shaft arranged to transfer torque to a vehicle wheel, a main epicyclic gear set arranged to control transmission ratio between the pedal shaft and the output shaft, an assist motor connected to an assist gear of the main epicyclic gear set, and a control motor connected to a control gear of the main epicyclic gear set. The control motor and the control gear form a control assembly of the power unit. The power unit includes a one-way clutch provided to the control assembly of the power unit and arranged to transmit rotation in only a first rotation direction.