2011 Kawasaki Ninja ZX-6R, Certified with six month warranty, this bike is in great shape and ready for a new home! Come check it out! - Pound for Pound, the Mightiest Middleweight Sportbike in History Technological tour de force. That’s the only way to describe the original Ninja 600 sportbike of 1985. Packing a liquid-cooled 16-valve inline-four (the first ever in a middleweight streetbike), wraparound twin-spar frame, anti-dive fork and aesthetics snatched right from the Grand Prix circuit, the original ZX600-A1 was a dominant, bigger-than-life middleweight. Apparently, some things never change.