Abstract: This invention relates to a mechanical fixture which simulates a four bar link drive system for pedal driven scooters and bicycles and the resulting drive system. A four bar drive link system simulator has a frame assembly, a proximal hinge attachment bracket, a bottom bracket simulator 0, a pair of crank levers, a pair of coupling levers and a pair of pedal levers. The frame assembly has a plurality of guide rails, including at least a proximal hinge adjustment rail, and a frame rail. The proximal hinge attachment bracket is connected to the proximal hinge adjustment rail. The bottom bracket simulator is attached or otherwise connected to the frame simulator rail.