No compromises: The newest Ninja is optimized for one thing — just as Kawasaki intended
by Lance Oliver
Folks, the 2006 Kawasaki ZX-10R is a dog.
That’s right, a dog.
Like maybe a greyhound with afterburners. With cornering skills like a caffeinated border collie nipping at wayward sheep. And brakes that bite like a pit bull.
Let’s face it, with racing technology trickling down to the 600 class in mouth-watering quantity, and with stock literbikes turning lap times equal to race-only Superbikes of not many years ago, it’s a great time to be shopping in the sporting goods aisle of your local motorcycle dealership. Which brings us back to the ZX-10R.
The five-millimeter difference
How much is five millimeters? Less than the height of a stack of four pennies. Less than a quarter of an inch.
So when the sportbike engineers talk about changes such as 4mm longer swingarm or moving the steering head 15mm, as Kawasaki did with the 2006 ZX-10R, it’s reasonable to ask: Can such small changes make a difference?
The answer is “yes,” and sometimes, “no.”
If you’re accelerating at half throttle up to 65 mph to merge into traffic on the freeway, you’re not going to notice a 5mm change in rear ride height. But as Kawasaki pointed out with no ifs, ands or buts, the ZX-10R was designed to go fast around a racetrack. And with the growing popularity of track days, more riders find themselves accelerating at full throttle, charging down straights at 150 mph, and trail-braking near the limit at lean angles that should never be attempted on the street.
That’s when 5mm makes a difference.
“When we change something 5mm, that’s a huge difference,” said AMA Superbike pilot Tommy Hayden. “You wouldn’t think so, but it is.”
Even when you’re not as fast as Hayden, 5mm matters. Just ask Kawasaki’s Jeff Herzog, who had the task of scrubbing in tires and setting suspensions on the bikes we rode at California Speedway. Kawasaki had us ride the bikes with the stock Dunlop Qualifier tires in the morning, and Dunlop Sportmax GP DOT-legal race tires in the afternoon.
Herzog set up the bikes with the stock 190/55-17 rear tire, then switched to the 190/60-17 rear GPs – and found that the suspension settings were all wrong, because of the GPs' higher aspect ratio.
“Even though it only raised the rear axle 4.5mm,” Herzog said, “it totally changed the handling of the bike.”
In the end, Herzog arrived at a compromise setting. Still, the change from the morning session to afternoon was pronounced. The grippier tires made the bike both faster and flightier for most riders.
So what’s the lesson in all this? Think about all the sportbike riders who shoehorn wider rear rubber onto their bikes, bolt on aftermarket shocks, or move fork legs up in the triple clamps. None of it will probably matter much on their commutes to work.
But when you take your bike to a track day, to experience all it’s capable of doing, and you scream into the first turn at redline in fourth gear – you’d better hope you either knew what you were doing or had good advice from someone who did. Because even a little change – even 5mm – makes a difference.
The Ninja Ten is the latest evidence of a new attitude at Kawasaki toward sportbikes. No more Mr. Nice Guy, no more sporty streetbikes with comfy ergonomics. Remember Kawasakis like the late-90s ZX9R? They were sportbikes you could ride all day without pain. But Kawasaki got tired of watching buyers rush past their street-focused sportbikes to buy harder-edged products like Yamaha’s R1.
“We’re no longer in the business of building sportbikes that make good street bikes,” flatly stated Karl Edmondson, sportbike product manager for Kawasaki Motors Corp. USA. Instead, the one and only goal of the 2006 ZX-10R is to get around a race track as fast as possible. Period, end of mission statement.
That means that the ZX-10R, introduced in 2004, is all-new for 2006. This two-year development cycle puts Kawasaki on par with the most aggressive schedules of any of its competitors.
The “old” (can a 2-year-old be “old?”) bike won more than its share of awards, but Kawasaki set out to improve it by systematically addressing the few areas that owners and the motorcycle press had complained about.
Tommy and Roger Lee Hayden, who rode the previous ZX-10R in the AMA Repsol Lubricants Superstock Series last year, wanted quicker side-to-side transitions. Many ordinary riders wanted slicker shifting and a steering damper to tame headshake. Edmondson emphasized that all those issues were addressed with the 2006 model.
Some of these goals were accomplished with changes that may seem counterintuitive to those of us without engineering degrees. For example, you want a low center of gravity for good handling, forward weight bias for front-end feel and to resist wheelies, and bigger valves for more engine power, right?
Not necessarily, it seems.
For example, the new engine layout on the 2006 ZX-10R raised the crankshaft 20mm, giving the bike a higher center of gravity to help with those transitions the Haydens were talking about. Kawasaki also bolted on a new swingarm that's 4mm longer and moved the steering head 15mm forward, which shifted the weight bias toward the rear. Along with a taller 55-section, 190mm rear tire (up from a 190/50ZR17), the engineers say the changes allow the rider to get on the gas sooner and stay on the throttle longer.
With handling addressed, Kawasaki massaged the powerband.
"Lack of horsepower has never been an issue with this bike," said Edmondson, so the focus was on creating a more linear powerband. The intake valves were reduced 1mm to 30mm, and the crankshaft, pistons, cylinder head and injectors are all new. Peak power remains the same, according to Kawasaki, but the torque curve is smoother.
Changes to the transmission allowed easier shifting, and, to address the most common complaint of all about the previous model, the company fitted an 18-position Ohlins steering damper.
Fortunately, Kawasaki’s focus on racetrack performance led them to rent California Speedway to introduce the new ZX-10R to the stateside press, so we didn't have to try to probe the bike's abilities on public streets — an impossibility with today's literbikes. These motorcycles reach speeds that can get your bike confiscated in some states — while still in first gear.
Walking up to the row of ZX-10Rs in the California Speedway pits, the visual changes are more obvious than the mechanical differences. The exhaust now features dual, underseat mufflers and is all titanium, except for the collector that houses the catalytic converter. Above the underseat exhausts are integrated rear turn signals in a broader tail section that's said to improve aerodynamics.
But the real difference in both appearance and aerodynamics is at the front, where the fairing is wider and smoother and houses a bigger ram-air duct flanked by smaller, dual-projector headlights. Improved aerodynamics is the closest thing to free horsepower, but the new fairing gives the bike a beady-eyed look the previous model didn't have.
Consider it part of Kawasaki's uncompromising focus on racetrack performance — aerodynamics trumps style. Which is not a bad thing as I near the 13,000-rpm redline in fourth gear on the front straight, brake, downshift to second and tip down the 11-degree banking into the chicane.
Having never ridden California Speedway before, I expected that spot, the fastest point on the track, to be the most intimidating. But the ZX-10R's excellent stability under braking, and nearly fool-proof shifting allowed by the revised slipper clutch and slicker transmission, made the end of the front straight just about my favorite spot on the track.
True to Kawasaki's promises, the power delivery was linear and abundant, with no peaks or surges as the needle swept up the new analog tachometer. In addition to the new, easier-to-read tach, the gauge cluster features a digital speedo, adjustable shift light and a built-in lap timer that will come in handy on those track days.
In the morning, we rode the bikes shod with a special-to-the-ZX-10R version of Dunlop's new Qualifier radial. In the afternoon, the bikes were fitted with Dunlop Sportmax GP DOT-legal track tires.
The tires made a surprising difference. On one hand, the GP's were soft and grippy. On the other hand, the new Qualifiers are surprisingly good, and the Ninja showed far more willingness to shake its head with the stickier tires. Some riders clicked up the Ohlins damper to a higher setting, but with several first-gear corners to negotiate, too much damping could be a problem, too.
Personally, I never rode the previous ZX-10R, which lacked a damper. But every time I made the transition from the infield to the front-stretch banking while accelerating, or when I hit the bumpy section around turn 10 in the infield, I was very glad indeed that the new bike had one. If I were a Kawasaki engineer charged with improving this bike, I'd have a hard time finding a place to start, except for the headshake at faster pace.
And the good news for us, and the bad news for that engineer, is that it is someone's job to make this bike better.
“You keep thinking that the improvements from year to year are going to get smaller,” said Edmondson. “But they’re not getting smaller.”
Instead, all the sportbike manufacturers continue to raise the bar.
So as good as the 2006 ZX-10R is, Kawasaki is already working on the 2008. The one that will (and must) fulfill the big Ninja's mission of getting around a racetrack even faster yet.
2006 Kawasaki Ninja ZX-10R specifications
Engine Four-cylinder, double-overhead cam, 16 valves
Displacement, bore x stroke 998cc, 76.0mm x 55.0mm
Compression ratio 12.7:1
Tires front and rear Dunlop Qualifier, 120/70-ZR17, 190/55-ZR17
Front suspension 43mm inverted cartridge fork, adjustable preload, compression and rebound damping
Rear suspension Adjustable preload, compression and rebound damping and ride height
Rake and trail 24.5 degrees, 4.0 inches
Wheelbase 54.7 inches
Front brake Dual floating 300mm petal discs, four-piston radial-mount calipers
Rear brake Single 220mm petal disc
Claimed dry weight 385 pounds
Pearl Solar Yellow