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The Campagnolo Gran Sport  was the first bicycle gear system that used the principle of the derailleur parallelogram, now universally adopted as the defacto bicycle gear changer and effectively what you can expect to see on your own modern day bicycle even now. It was designed and patented by the Vicenzan Tullio Campagnolo, owner of the Campagnolo company and presented to the public for the first time at the Paris Cycle Show in October 1949.

The first version was a model with two cables. It was never sold and produced in only 10 prototypes: one of two cables used to drive the chain to the largest sprocket, the other would move it over to the smaller one. A pulley with two wheels then served by tension, so that the chain would always be the correct tension. The revolutionary aspect of this change was the fact that the cyclist could continue to pedal forward (even though the change  often required to stick a pedal backwards for placement) without having to slow or even stop.

The following year  the single cable model was created, the ancestor of all modern derailleurs. While pulling the cable carrying the chain on the largest sprocket, you could go over small ones that cable release, thanks to the strength of a spring located in the derailleur.

During the 1950s the  Gran Sport gear system underwent many changes and innovations, becoming the derailleur in wide use among professional cyclists. Campagnolo also started to mark "Gran Sport" on other components, from the pedals to the front derailleur.

During the 1960s and 1970s saw the introduction of other components  to the Gran Sport range. High quality components but less than that of the premeir Record gruppo including cranks, pedals and seat post. This new change involved releasing them as a new groupset and this was given the  name Nuovo Grand Sport.