What does the Kawasaki Ninja ZX-10R have in common with Spinal Tap? Although clearly not a motorcycle numbers man in the purest sense, Nigel Tufnel of Spinal Tap clearly understood that more really can be much more. When he said, “If we need that extra push over the cliff, you know what we do? [We] put it up to eleven.” he could well have been talking about Kawasaki’s new Ninja ZX-10R, such is the awesome capability of this year’s new, more refined machine.
First introduced to a somewhat stunned public in 2004, the first ZX-10R appeared to have more of everything. Typically Kawasaki, it produced more power than any of its peer group, but that was a bit of a double-edged sword. The punch was delivered in such an untamed rush that even super-smooth factory pilot Tommy Hayden found it difficult to control, claiming that on his Superstock machine the engine “just hit too violently.” The over-enthusiastic power delivery wasn’t helped by a swingarm pivot that was rumored to be too high, thereby making traction a challenge, as well as a slightly nervous chassis that also lacked some feeling at the front end. It’s not that the big Kawasaki was a bad bike. Far from it. The ZX-10R won many accolades, but, as Nigel mentioned earlier, it felt like the bike had been pushed over the cliff toward 11.
Photographs by Tom Riles. (Click images to enlarge)
That was last year. And Kawasaki, fresh on its success in the Supersport category, decided to accelerate development of its model range—the ZX-10R being one of the first to come into its sights. An outright power increase for the ram-air-assisted 184 hp motor was unnecessary, but certainly the delivery needed improvement. Around 90 detail changes were made to the engine alone, including an increase in flywheel weight, fine-tuning of the injection system and inlet tracts and a more progressive throttle pulley. When combined, the changes increased the midrange power and, more importantly, helped smooth out the power pulses, allowing the engine to generate its thrust in a more controllable fashion.
Accelerating onto the banking out of California Speedway’s long sweeping left-hand final corner, I was impressed with the big Ninja’s throttle connection and how small increments of twist grip position could be felt at the rear wheel. It was hugely powerful and obviously capable of overwhelming the brilliant rear Dunlop Qualifier tire. However, the chassis and suspension feedback, in combination with those tires, was excellent, and the bike is wholly manageable.
Clearly Kawasaki’s engineers have got the EFI right. One of the real tests of fuel injection mapping is the transition from an off-throttle situation to back on. Typically, this occurs—especially at the track—at maximum lean angle and then accelerating through the corner exit. It is a great test, because anything less than smooth power delivery leaves the rider without confidence at best, and thrown on the ground at worst. The ZX-10’s exemplary fuel injection is smooth and consistent, and I especially appreciated that through turn five, a relatively slow, double-apex left hairpin. Rolling back on the throttle caused the bike to swiftly, but elegantly, unfurl itself from the corner and rip down the short straight as if a giant hand was insistently pushing from behind.
Photographs by Tom Riles. (Click images to enlarge)
Kawasaki’s engineers also turned their attentions to the ZX-10R chassis. The previous model’s nervousness was cured by slightly relaxing the front end. Caster angle was increased, the steering head was moved forward and the aforementioned swingarm pivot was lowered by 4mm to help put the power to the ground. Deciding that the Ninja needed a steering damper, Kawasaki held true to its design maxim of no compromises and added an adjustable Öhlins unit that now sits proudly between the triple clamp and front of the gas tank. Dunlop Sportmax GP race compound track tires replaced the street tires for the afternoon session. The extra grip reintroduced a little of the previous Ninja’s front end nervousness, especially through the rough pavement section of the track’s chicane-type section before the crossover bridge. Coming hard on to the power out of the previous slow right-hander created jet-turbine like acceleration—the only snag being that the track line isn’t precisely straight from that point. The mild right-then-left transition over rough pavement tested the front end and more centralized mass of the chassis. The Ninja transitioned beautifully from side-to-side while under power, and two clicks up on the steering damper then brought the mild head shaking back under control.
Brakes now seem to be a Kawasaki strong point. Literally. On the ZX-10R, the radial-pump master cylinder and radial mounted calipers actuate on petal type rotors; the unique shape improves cooling and reduces unsprung weight. Although formidably powerful, the impressive stopping power is made more useful by the lack of harsh grab when initially applied. It is vital when braking hard from three-figure speeds that there is plenty of linear feel and, with the ZX-10R’s brakes, a progressively stronger pull on the right lever increases stopping power in a confidence-inspiring and extremely manageable way.
Kawasaki’s range of Ninja motorcycles has the simply stated goal of being the number one circuit performer in its category. With a detailed series of upgrades to both the motor and chassis, the new ZX-10R is faster than its predecessor, more user-friendly, and yet it somehow manages to keep that slightly raw character too. With its awesome engine and uprated cornering performance, those dual menacing pipes exiting from the rear and that aggressive new bodywork styling, this Kawasaki goes as good as it looks—and that’s up to “11”—yet it somehow manages to do it without feeling as though you’ve been pushed over the cliff.
Photos by Don Williams