2011 Kawasaki Ninja ZX -6R, 2011 Kawasaki Ninja ZX -6R The Top Contender in the Middleweight Category Power. Speed. Handling. Dominance. The Ninja ZX -6R packs all this and more underneath its 599cc engine, twin spar aluminum frame and advanced Showa suspension. Whether you're a street rider or a racer, this bike packs the kind of potent strength that will satisfy even the most discriminating e...