 The 2006 Aprilia RX/SX 50s are the renovated successors of the Aprilia RX 50 first produced in 1992; the panels and layout are based closely on the bigger displacement Aprilia RXV/SXVs.The engine in the Aprilia SX 50 is sourced from Derbi/Piaggio (D50B0/D50B1).This engine is used in the Derbi Senda DRD/X-Race/X-Treme supermotos and crossers, as well as the 2006 onwards Derbi GPR 50 and Aprilia RS 50 road bikes.