A drive train for a wind-up injection device is described. The drive train includes a torsional energy storage adapted to be loaded or unloaded by a rotatable element, a rotatable user handle, a rotationally driveable expelling mechanism adapted to expel the liquid drug, and a clutch element coupled with the torsional energy storage via the rotatable element and including a ratchet for maintaining the rotatable element at one of a number of discrete angular positions against the torque of the torsional energy storage. The clutch element is adapted to transmit the torque from the user handle to the torsional energy storage, or alternatively from the torsional energy storage to the expelling mechanism. The ratchet is switchable from one position to an adjacent position by a torque transmitted from the user handle to the torsional energy storage. The drive train is adapted to dampen torque peaks visco-elastically and/or visco-frictionally.