Aprilia dirt bikes include the 2-stroke RX 50 and RX 125 as well as the twin-powered RXV 4.5 and RXV 5.5 enduros, along with the MXV motocrossers. The Supermoto SXV lineup utilizes the Twin powerplant with the larger displacement Dorsoduro a street-oriented supermoto.Aprilia’s first racing success came in the off-road realm during the mid ‘70s in the Italian and World motocross championships. Aprilia still produces off-road machinery like the enduro RXV 4.5 and 5.5 and the 2-stroke RX 50 and RX 125. For 2009 the Italian firm pushes forward with a Twin-powered motocrosser – the MXV 4.5, which will compete in the FIM Motocross series. Supermoto versions of the XV Twin are the SXV 4.5 and 5.5.