Road Test Review
As time passes, people tend to get slower and heavier, and their mass becomes less centralized. In contrast, sportbikes slim down, firm up and have more energy. If I could reinvent myself every two years, then I wouldn’t have to suck in my gut to zip up my leathers nor feel like a grizzly bear on a bicycle when turning laps. Between 2007 and 2009, the Kawasaki Ninja ZX-6R lost 22 pounds, and what mass remained was pulled inward. I wasn’t quite so disciplined.
Design mantra for the 2009 ZX-6R was “precise control for maximum excitement.” That meant, in addition to shedding and centralizing mass, dialing in the engine and chassis for just-right responsiveness at hair-on-fire speeds. Kawasaki massaged more sake into the ZX-6R’s Kobe beef motor. Its goals were more precise throttle control to better connect the rider to the rear wheel, and more midrange torque for stronger drive out of corners. Like well-marbled steak that melts in your mouth, Kawasaki sought to deliver a rich, satisfying experience.
The ZX-6R’s twist grip now more directly translates what you want into what you get. Combustion efficiency has been improved by higher-current ignition stick coils and cylindrical guides in the airbox for more precise fuel delivery. Longer throttle bodies provide a smoother transition between the main and sub-throttles for better airflow. And cylinder porting has been revised for more efficient filling.
To boost midrange performance while maintaining top-end power, velocity stacks now have dual-height inlets. High-load cam profiles can be used thanks to optimized cam nitriding and more durable tappets. Pistons have been redesigned with new profiles, improved crown finishing and low-friction molybdenum skirt coating. Parasitic losses have been reduced with low-tension piston rings and motion-stabilizing cam-chain guides. Exhaust collector layout has been redesigned to increase power across the rev range.
Motorcycles must carry around a load of skin and bones, and they do so much better at speed when the chassis is balanced and dependable. The chassis shouldn’t do anything I don’t want it to do, and when I get a little carried away, I’d like for it to get me out of trouble like my protective older brother. While the ZX-6R’s frame is essentially the same, rigidity has been altered for better fore-aft balance and more feel for rear-wheel traction. Front-end feedback has been improved with revised front engine mounts and head pipe and steeper rake (from 25 to 24 degrees). When leaning into turns, the flatter, slimmer fuel tank provides more communicative body contact.
Centralizing mass and reducing weight are subtle processes, often invisible to the naked eye. Just as many hands make light work, myriad small changes can result in a significantly tighter, more flickable package. To pull mass inward, the ZX-6R’s engine was rotated forward around the output shaft and the head pipe was raised. New exhaust with a pre-chamber and short muffler has been moved from under the seat to the right side to further centralize mass.
Extensive nipping and tucking resulted in a loss of 22 pounds. Over a pound was saved by making camshafts from chromoly steel and engine covers from magnesium. Tweaks to the top injector mounting plate, transmission gears, oil pump, starter and coolant reservoir further reduced weight. The fork, two-piece aluminum subframe, ram-air duct, frame brackets, throttle cases and license-plate holder are all lighter.
Big news on the suspension front, literally, is the use of a Showa Big Piston Fork. Compared to the fork on last year’s ZX-6R, main piston size has been nearly doubled (from 20mm to 37mm), quadrupling surface area. Damping pressure was significantly reduced while overall damping force remains the same. The slide pipe thus moves more smoothly, particularly during the initial part of the stroke, for less fork dive under braking and more stability on corner entry. The 41mm, fully adjustable male-slider fork has fewer internal components than a conventional cartridge-style fork, which saves weight. Win-win.
All well and good, that, but you might have skimmed over the preceding paragraphs to get to the bottom line: What’s it like to ride? To find out, Kawasaki rolled out the red carpet at the ZX-6R’s world press introduction in Japan. After an introductory tour of Kawasaki’s shipyard, train factory and headquarters in Kobe (see Rider, October 2007), they put us back on a plane to Kumamoto in southern Japan. About an hour’s bus ride up into the mountains from Kumamoto is Autopolis, a 2.7-mile racetrack located within Aso Kujiyu National Park.
Having logged track time on 2007-2008 ZX-6R’s, I’ll cut to the chase: Kawasaki nailed it. When the tire warmers came off the race-spec Bridgestone BT003’s and we were let loose on the track, the caffeine in my system got a turbo boost of adrenalin. Built on a hillside, Autopolis is a very fast circuit with frequent elevation changes. As I learned the braking markers, turn-in points and lines during the first couple of sessions, the ZX-6R was predictable, forgiving and always ready for more. And as I got more comfortable and went faster, screaming down the front straight at more than 140 mph, the Ninja still had more to give. I felt like Beatrix Kiddo (aka Black Mamba) being schooled by Pai Mei in Kill Bill Vol. 2: “Your so-called kung fu is really quite pathetic.”
Just like Black Mamba, I got better with practice (though I didn’t learn the Five-Point-Palm Exploding-Heart Technique). And that’s a beautiful thing: riding a motorcycle that is so well designed that it motivates you to test your limits. Brake later, turn in quicker, accelerate harder. The Ninja became my master, and I its pupil.
Set up for Autopolis, the suspension was firm but responsive to uneven pavement. The Big Piston Fork lived up to claims, resisting front-end dive on hard braking and keeping the front tire on line. Even though the brakes–300mm front petal discs gripped by opposed four-piston Nissin calipers, and a single 220mm rear petal disc gripped by a pin-slide Tokico caliper –are unchanged from last year, I pushed harder and got more out of them. Downshifts were smooth courtesy of the slipper clutch. Ergonomics were tightened up–bars moved closer to the rider and the seat made narrower, lower and shorter–but felt natural and comfortable for the track, even with my 6-foot-plus frame.
Riding the 2009 Kawasaki ZX-6R for two days on the track where it was developed, with technicians to fiddle with settings and change tires every second session, brought to mind kata, the Japanese word for choreographed movements in theater, tea ceremonies and martial arts. In its element, the new ZX-6R felt nearly perfect. But how will it fare outside the temple walls, on the street?