Abstract: A drive mechanism for a vehicle propellable by muscle power is provided, wherein the drive mechanism comprises a first actuating element (104) which is moveable by a stroke along a movement path, a first driving element (211), a first gearing comprising a driving shaft (107), and first returning element (212), wherein the first driving element (211) is coupled between the first actuating element (104) and the driving shaft (107) in such a way that actuating element stroke induces a movement of the driving shaft in a first direction, and wherein the returning element (212) is coupled between the first actuating element (104) and the driving shaft (107) in such a way that it induces a movement of the driving shaft in a second direction opposite to the first direction.

Abstract: Vehicle propelled by muscle power, in particular scooter, with at least one driving wheel and at least one tread surface (5, 5?) which is movable via a tread surface stroke, wherein the force transmission from the at least one tread surface (5, 5?) to the at least one driving wheel takes place by means of a driving element (6, 6?) which is guided with a nonpositive fir via a drive shaft (8, 8?) which is coupled to the driving wheel via a freewheeling mechanism, wherein the drive shaft (8, 8?) and/or preferably at least one deflecting roller (7, 7?) is/are divided into at least two axial regions (7b, 7c; 7b?, 7c?, 8a, 8b; 8a?; 8b?) with radii which differ from one another or are variable, and the driving element (6, 6?) is divided into partial sections with different cross sections which are designed in such a manner that the partial sections (6a, 6b 6c; 6a?, 6b? 6c?) of the driving element (6, 6?) are guided within the tread surface stroke (O-U) on the respectively corresponding axial region of the drive shaf