What is disclosed is a drive device for a bicycle driven by an electric motor, having a main frame having a swing arm bearing, and a rear linkage element arranged at the swing arm bearing. The drive device has a pedal crank as a first drive for providing a first drive force, having a first drive shaft, a center electric motor as a second drive for providing a second drive force, and an output element having an output shaft, configured to receive the first and/or second drive forces and transfer same to the bicycle wheel to be driven. The center axis of the output shaft is radially distanced from the center axis of the first drive shaft and the output shaft is arranged relative to the swing arm bearing such that a radial distance between the center axis of the swing arm bearing and the center axis of the output shaft is smaller than a radial distance between the center axis of the swing arm bearing and the center axis of the first drive shaft.