Valentino Rossi once described the Yamaha's inline four-cylinder motor developed for their M1 MotoGP race machine as the "sweet motor."
The smooth but dramatic low-down torque is thanks to its unique cross-plane crankshaft design that gives an off-beat firing order, and the engine actually sounds and behaves a lot like a typical V-four. Yamaha have fitted this technology to their R1 superbike flagship and the result has (easily) been the best-selling liter-bike in the US. No big surprise there. Read On: http://www.ultimatemotorcycling.com/2012-yamaha-r1-traction-control-review