Three years ago Kawasaki caused a stir by bringing out a 636cc middleweight sports motorcycle. Their logic in offering the Ninja 636 was fair enough — road-riders aren’t bound to the 600cc limit that prevails on the racetrack, so why not give them the extra midrange grunt provided by the added engine capacity?
Last year the Japanese factory took things a step further by bringing out two new models. The 636cc Ninja ZX-6R was much more sporty than its predecessor, while the track-oriented ZX-636RR used a 600cc engine to retain its eligibility for the 600cc class on racetracks around the world. The racing model also boasted superior suspension and a slipper clutch, and a race kit was available to give it really serious power on the racetrack.
Now the all-new 2005 Ninja ZX-636R is looming over the horizon, and with it Kawasaki wants to prove that you can have your cake and eat it too. With a new 636cc engine, tuned to give even more grunt, married to host of features previously found only on the ZX-6R track model, the new Ninja now delivers better-than racetrack performance on the road.
The latest Kawasaki middleweight is most easily identified by its new bodywork and — a first from the Big Green K — its sexy underseat muffler. The bodywork closely resembles that of Kawasaki’s Moto GP machine and is the most aerodynamic yet offered by the factory, which claims that the slippery shape is worth about 10 horsepower at 250 km/hr. A flush-surface LED tail light improves visibility, and integrated front turn indicators keep the bike’s lines tidy and streamlined.
Under the skin lies an all new motorcycle. A longer ultra-trick braced swingarm pivots 13mm further forward in the brand new aluminium frame to give improved rear suspension action, and the shorter wheelbase sharpens the steering and gives improved control over the front wheel during fast cornering.
The engine of the 2005 ZX-6R has been completely upgraded. New crank cases, with thicker castings to improve rigidity and reduce vibration, tilt the cylinders five degrees closer to vertical, allowing the engine to be mounted further forward in the frame. A lightweight aluminium oil cooler replaces the previous stainless-steel one, and the width of the oil pump has been increased, while its drive ratio has been changed to reduce its spin rate. A deeper oil sump lowers the oil level and reduces loss to windage, and the crank shaft has been strengthened and fitted with larger diameter main bearings to cope with the extra power.
A new cylinder head locates each pair of inlet and exhaust valves further apart to allow better breathing, and new pistons with reshaped crowns and low-friction skirt profiles now fill the bores. The 2005 ZX-6R also gets larger valves and the performance inlet and exhaust camshafts that formed part of the race-kit for the 2003 Ninja ZX-6RR.
Kawasaki has revamped the new bike’s fuel injection system to suit the new mechanicals. Large bore 38mm throttle-bodies feature oval-shaped sub-throttles to increase airflow without having to widen the engine width. This technology, used for the first time in the middleweight supersport class, improves intake efficiency by 20%. The ram-air system has also been upgraded, and a larger-capacity airbox containing secondary fuel-injectors aids in providing crisper throttle response and higher power output. Also new is an exhaust valve fitted in the under-seat silencer. This controls pressure waves in the exhaust system and boosts low and mid range power output.
Like the ZX-6RR, the new ZX-6R is now fitted with a slipper clutch to reduce rear wheel hop when downshifting at high revs. The transmission has new, stronger bearings and the third gear ratio has been raised.
Last year’s Kawasaki was the first production bike in its class to feature radial mounted disc brakes, and this year they’re even better. Four independent brake pads — one for each piston — are used in the front calipers for even wear and improved heat resistance. A smaller diameter rear disc is used to keep unsprung weight to a minimum.
Instrumentation on the middleweight class King of Grunt is comprehensive. The sporty dash now boasts a bar-type LCD rev counter, a digital LCD speedometer, an adjustable shift indicator lamp to let you know when to hook the next cog without watching the rev counter, and a stopwatch-style lap-timer. There’s also a digital temperature gauge, a clock, a trip-meter and a full range of idiot lights.
The new Kawasaki ZX-6R will be available in South Africa in time for Christmas. Pricing has not yet been finalised.