The invention relates to a power train for a pedal vehicle, comprising a first motor and a second motor, the second motor being engaged with the axle of the crankset and the first motor being connected to a planetary gear. A planet carrier is connected to an output plate of the power train, which comprises a measuring element arranged so as to produce a measuring signal indicating torque supplied by the first motor and a control unit producing a velocity control signal to be supplied to the first motor and a torque control signal to be supplied to the second motor on the basis of the angular velocities of the motors.