Campagnolo's first successful derailleur had been the "Cambio Corsa," which used a system of seatstay-mounted control rods to loosen the rear quick release and then move the chain back and forth with a "fork" device. The fork sat around the chain on top of the chainstay, so that shifting occurred when backpedaling; since it had no jockey pulleys, the wheel moved back and forth to take up slack in the chain. Once the shift was complete, the quick release was re-tightened, and the rider could start pedaling again.