a free wheeling device 6 on the flange like element 5 by means of a lever 28 with an associated bowden cable 12 as well as a restoring spring not shown in the drawing the flange 7 can be selectively engaged with the stator 8 which is provided with bolts 10 or with the rotor 9 which is provided with bolts 11 the pedal drive can be selectively connected in this way with the stator 8 or the rotor 9 frictionally connected as the housing of the hub it is thus selectively possible to add the rpm of the pedal drive and the rpm of the electric motor or to add the torques of the pedal drive and the electric motor the selective transfer of force of the muscle power to the stator 8 or the rotor 9 of the electric motor can be accomplished by means of any arbitrary coupling the stator 8 is rotatably seated on the central axle 1 by means of the ball bearing 13 and the free wheeling device 14 the free wheeling device 14 prevents retrograde rotation of the stator 8 when no pedaling takes place or when the pedal drive is connected with the rotor 9 the stator stampings 15 and the windings are applied to the stator 8 and get current by means of an appropriate device in the case represented via collector rings 16 and carbon brushes 17 the signals from the sensors 19 for detecting the rotor position are transmitted via collector rings 18 and brushes 20 or similar devices the data regarding the relative position and relative movement.