Abstract: The invention relates to a compact installation gear with, for instance, a ?? derailleur chain and a derailleur for setting a transmission ratio between a crankshaft and a rear hub of a bicycle. To that end, the gear comprises a compact housing with the crankshaft included therein, with a slidable driving first sprocket engaging, via the derailleur chain, a selected second sprocket which forms part of a series of second sprockets mutually different in diameter, located on a secondary shaft with a third sprocket mounted thereon outside the housing, which, in turn, via a roller chain, drives a fourth sprocket on the rear hub. The transmission ratio can be set with the aid of the derailleur by moving the derailleur chain over the different second sprockets while at the same time moving the driving first sprocket to a position directly opposite the selected second sprocket.

Abstract: The invention relates to a compact installation gear with, for instance, a ⅜″ derailleur chain and a derailleur for setting a transmission ratio between a crankshaft and a rear hub of a bicycle. To that end, the gear comprises a compact housing with the crankshaft included therein, with a slidable driving first sprocket engaging, via the derailleur chain, a selected second sprocket which forms part of a series of second sprockets mutually different in diameter, located on a secondary shaft with a third sprocket mounted thereon outside the housing, which, in turn, via a roller chain, drives a fourth sprocket on the rear hub. The transmission ratio can be set with the aid of the derailleur by moving the derailleur chain over the different second sprockets while at the same time moving the driving first sprocket to a position directly opposite the selected second sprocket.