The Aprilia RXV/SXV series are four-stroke, v-twin off road (RXV) or dual sport supermoto (SXV) motorcycles produced by Aprilia since 2006. Both versions have either 449 cc (27.4 cu in) or 549 cc (33.5 cu in) engine sizes. The RXV/SXV's frame is made of a combination of tubular steel and aluminum plates. The compact engine fits into the frame in such a way that the air filter sits on top of the engine, below the gas tank, rather than the more traditional under-the-seat location. This allows for a lower distribution of weight. (Source: Wikipedia.org, CC BY-SA)