At this year바카라™s EICMA motor show, Aprilia caught everyone바카라™s attention with its stunning concept called the RS 660. At the show, Aprilia revealed that the Rs 660 will be powered by a parallel-twin motor derived from the V4 unit that powers its flagship model, the RSV4. Now, the much-anticipated middleweight sports bike has been spotted testing at Italy바카라™s Vallelunga circuit. More importantly, there were two different versions of the motorcycle at the circuit and that has piqued our curiosity immensely.