 The Speed Four has the clip-on handlebars of the TT600, rather than the motocross-inspired handlebars of the Speed Triple and other streetfighters.The Speed Four is mechanically similar to its predecessor, the TT600, with the exceptions of the cam profiles, ignition and fuel injection mapping, front spring rate, and other minor concessions to its streetfighter style; the frame and fully adjustable suspension are race-ready.The engine is a 599 cc inline-four-cylinder engine, as used in the TT600.