Kawasaki's monocoque frame is a hollow composite of aluminium parts. Originally conceived by Kawasaki engineers, it uses the engine as a fixed member so that chassis rigidity is formed not only by the frame, but the combination of the frame and engine together. Joining the engine and front and rear suspension units, the hollow box-style frame envelops the engine from above. In addition to being made from lightweight materials, its main section also acts as the air cleaner box and battery box, enabling parts to be reduced for even greater weight savings. Further, because the frame does not run beneath or alongside the engine, the chassis can be made very compact. Especially on large-displacement models, the slim chassis design of the aluminium monocoque frame contributes to ease of riding. The aluminium monocoque frame was originally developed by Kawasaki in the 1980s for their World Grand Prix works racer. In an era where steel pipe frames were the norm, the aluminium monocoque frame that debuted on the KR500 took the world by surprise. First featured on a mass-production model on the 2000 Ninja ZX-12R, this original Kawasaki technology has evolved and can be found on our large-displacement flagship models.