Kawasaki’s officials make no bones about the 2006 Ninja ZX-10R’s tightly focused racetrack orientation, and why should they? The company needs a fast production-based liter-bike to qualify for inclusion in both AMA and World Superbike championship races. The closer the original product is to a dedicated race bike, the better it’ll be when modified and developed according to the regulations of the respective championship leagues.
Besides, where else can you really exploit the performance of a 998cc four-cylinder rocket bike other than on a track? For 2006, Kawasaki’s new ZX-10R boasts over 180-horsepower when gulping high-speed air through its gaping nosecone scoop. Even without the so-called Ram Air supercharging, its static output is a respectable 173-horsepower (corrected to SAE units) at 11,500 rpm, and that’s enough to loop the bike if you’re silly enough to try to use all of it at low speed.
But despite the chief Ninja’s formidable power and performance, it proved easy to ride around the California Speedway in Fontana, California, at the new model’s U.S. introduction. Having acquired an impressive reputation with its ‘04/05 ZX-10R models, Kawasaki made a host of revisions to the latest bike to tame some of the early bike’s wilder tendencies. At the same time, the company strove to make the new bike quicker around a track.
In fact, it’s safe to say that the 2006 ZX-10R Ninja has been virtually reinvented, with a new engine, new chassis, new bodywork, new exhaust system, and new instrumentation. Since this machine replaces a model that won a slew of comparison tests against bikes in the same class, you might wonder what needed improvement.
Well, nothing’s perfect, and Kawasaki wanted a more linear power delivery to avert the sudden mid-range surge of the previous engine that could upset the bike in certain circumstances. Such as when fully heeled over, coming out of a corner. So the engineers revised the induction path with a more efficient ram air duct, a new airbox, and revised intake ports. Slightly smaller intake valves were fitted to increase gas velocities.
Ultra-fine injectors were adopted to further improve fuel mixture and combustion efficiency. The burnt gases are now expelled through a 4-into-2-into-1-into-2 titanium exhaust system that incorporates dual catalytic converters to meet stringent Euro III emissions standards.
With the engine repositioned slightly higher in the frame, the ZX-10R’s center-of-gravity has been raised to improve mass centralization for quicker roll response. Almost everything in the engine has been revised—the crankshaft, the cylinder head, the pistons and rods. Even the slipper clutch (which eliminates rear-wheel lock-up under engine braking) benefits from a modified anti-chatter disc.
Some key revisions were made to the bike’s transmission too. In response to criticisms about last year’s bike’s shifting, all shaft splines in the gearbox were barrel ground, and the shift linkage was revised for smoother action.
To our surprise, Kawasaki engineers moved the alternator from behind the engine (where it was located on the prior model to reduce engine width), to the end of the crankshaft for more flywheel effect to smooth power fluctuations. But since they moved the starter motor to a spot behind the cylinder block at the same time, the engine is still narrow enough to allow a dizzying 52-degree lean angle.
To increase the bike’s stability without losing the responsiveness that made the ZX-10R such a good track mount, the steering head tube was moved forward, increasing the castor angle and shifting the chassis weight balance slightly rearward. The rear swing arm was redesigned for additional stiffness and its pivot point was lowered to improve rear wheel traction. Also to improve traction, the rear tire now has a 55-percent aspect ratio, replacing the 50-series tire on the “old” model.
The result, as we discovered on the track at Fontana, is a surprisingly friendly, amazingly fast sportbike. Trust me, an invitation to ride a bike this strong on a track this fast is pretty intimidating to someone with relatively limited racetrack experience. Particularly when Tommy and Roger Lee Hayden, Kawasaki’s superbike race team siblings, occasionally strafe you while shaking down their new race bikes. But despite the fact that this new Kawasaki is one of the fastest motorcycles money can buy, I found the experience very reassuring.
The ZX-10R’s throttle response is predictable at every point of the engine’s operating range, particularly when you learn the track layout and start developing a rhythm. Then the throttle picks up smoothly at corner apexes and the bike drives out smoothly on a rapidly swelling wave of power. The gearbox worked flawlessly during our test session, and the brakes were reliable and fade free for all but the most intense riders, some of whom reported a little fade after repeated hard use. When checking out the two big “petal” discs up front, clamped by dual four-piston brake calipers and activated by a radial-action brake lever, it’s hard to see brake fade ever being a problem on the street.
The bike certainly changes direction willingly, and the new-for-2006 _hlins steering damper made it easy to get on the gas early and ride out any twitchiness arising from full power across bumpy sections. All in all, the new Kawasaki ZX-10R proved a remarkably civilized vehicle for a mechanism whose track intent is so proudly proclaimed. Having said that, the surface at Fontana is generally smooth, and the riding style of all the invited journalists was unequivocally dedicated to going fast. Really fast. How the bike conducts itself on the public road may be another matter, even though modern motorcycle suspension technology has proven remarkably adaptable.
I expect the riding ergonomics and overall versatility will be found entirely acceptable to the kind of customer this bike attracts. We all found the bike surprisingly comfortable for something with a performance envelope as extreme as this. My bet is that the ZX-10R will exceed the expectations of everyone that rides it on the road. What more can one say for a machine that lives for the track?