Per the now-usual modus operandi of upgrading sportbike models every two years by the Japanese manufacturers, Kawasaki has revamped the ZX-10R substantially from its last '06 iteration, instilling a host of modifications aimed at re-establishing Team Green's prominence in the literbike class. The aggressive-looking new 10R appears to be a no-holds-barred design with numerous changes drafted in straight from the firm's Superbike and MotoGP racing efforts, with even more of a track focus than ever before.
The 10R wasn't the only big Kawasaki that was entering its two-year development phase, however. KHI engineers surely caught wind of Suzuki's new Hayabusa that is scheduled to be unveiled for '08, and couldn't let Kawasaki's flagship sportbike sit idly by and get one-upped by its main rival. A surprising boost in the 14's overall power (as if it actually needed it...) was accomplished via some subtle changes.
Even Team Green's little Ninja 250R wasn't left out of the upgrade parade. A number of changes to Kawasaki's original entry-level Ninja have taken it a step closer in looks and performance to its high-performance brethren.
Like last year's ZX-6R, Kawasaki engineers employed the services of a top-flight racer to help with machine development. In the new ZX-10R's case, it was former World Superbike and MotoGP contender Akira Yanagawa, who still competes in the All-Japan Superbike Championship (in fact, at press time, he was a close second in the title chase with two rounds to go).
Because Kawasaki engineers wanted to keep the previous model's superb midrange power intact, bore and stroke remain the same with the all-new engine. A one-piece upper crank- case and cylinder casting shaves more than two pounds of weight and increases overall case rigidity, and the clutch and transmission shafts retain the stacked configuration to cut overall engine length front-to-back. Additional weight was saved by oil channels cast into the cases (replacing external oil lines), and specially designed internal fins in the liquid-cooled oil cooler improve its heat dissipation capacity. The oil pump gear ratio has been refined along with the aforementioned lubrication system changes to reduce drag and improve efficiency.
The crankshaft is all-new, and even though the overall assembly weighs about two pounds less than the previous unit, it still maintains the same inertial force. A new water pump using the same style impeller as the ZX-14 improves coolant flow with less friction, and a new-generation radiator with more tightly packed cores cuts weight and improves cooling.