The ZX-6R boasts the biggest, baddest motor, superb radial-mount brakes and a rigid, race-ready chassis, adding up to an excellent track day or street weapon.
Kawasaki ZX-6R Big Slugs
The ZX-6R reminded us a lot of its potent big brother, the ZX-10R. Not only does a rider feel the family lineage from the saddle, but the Kawi motors are simply a step above the rest. The 10R gets its mondo power honestly but the 6R is a factory-produced “sleeper,” packing an additional 37cc over the trio of true 600s in this test. This may be seen as an unfair advantage, but at just $7999, Kawasaki doesn’t charge extra for the bigger slugs. Only the Yamaha is as cheap, so considering a seat cowl is included on the ZX and not the Yamaha, it is the best value of the bunch.
The big-bore Kawasaki 636 received revisions to its suspension damping rates for 2004, addressing our biggest complaint with last year’s bike. The result is more compliant suspension control that makes it possible to balance the chassis with clicker adjustments.
With nearly identical trail and wheelbase figures as the Gixxer, the green meanie handles similar to the Suzi; the ZX’s 0.5-degree more rake balanced by the GSX-R’s standard-issue steering damper. However, the Kawi’s 20mm smaller-diameter brake rotors and 2mm-smaller 41mm fork gives it a lighter front end. Combined with the only 65-series front tire (instead of the 70s on the rest) and the lightest weight (414 pounds), the ZX flicks fast with no flex. The sketchy feeling of last year’s model has been banished, and several testers remarked about how stable it had become, especially with the calming influence of the taller 120/70 Michelin H2 Pilot Race we fitted for track use. Front-end feel is surprisingly good, with direct feedback from the front tire.
As good a package as the ZX is, discussion always comes back to that mega motor. While the other 600s may produce competitive (though not superior) power below 7000 rpm, the 6R clears its lungs at that point and has a significant advantage until the rev limiters kick in to interrupt the party. And in any sport-riding environment, each succeeding gear shift keeps the rpm in its fun zone, giving the speed-mad Kaw an obvious power advantage over the four-cylinder crowd. The extra cubes really pay off in strong corner exits, and it can nearly hang with the others even when stuck in a gear too high.
The ZX also received praise for the power and positive feel of its brakes. The radial-mount 4-piston calipers offer lots of feedback and were judged to be right up there with the similar setup on the Gixxer. Kawasaki doesn’t claim any changes to the ZX’s gearbox, but our riders scored its transmission much higher than last year. Shift action is light if not overly positive, and one of the only beefs was Kawasaki’s neutral finder system that forces a rider to come to a complete stop to easily access neutral.
Even with green-tinted glasses, we found a few things to criticize about the 6R. First and foremost is the frustrating circular LCD tachometer. It’s angled too vertical, making the dim LCD sweep even harder to read, and its dim, gray display gets washed out in sunlight. At least it has a more easily read programmable shift light for your high-rpm cues. Kawasaki has attempted to pop this pimple with a new set of instruments for the revised 2005 model that is yet to be released.
With a midrange hit of torque that can’t be matched by the other 600s and no less than 45.3 lb-ft of torque available at 11,200 rpm, monster wheelies are a snap with the Kawasaki ZX-6R.
With bigger pistons rocking up and down inside its cylinders, it’s not too surprising the ZX has the most pronounced vibration in this group; the CBR and GSX-R were also singled out for exhibiting a high-frequency buzz. The seat of the 6R is fairly tall (like the CBR), and that causes a rider to slide forward into the rear of the tank. Several of our testers complained about the pressure this put on their testicular region, so we’d hope this will also be addressed in the new ZX. While they’re at it, we’d appreciate if Kawasaki would add a steering damper (shades of the literbikes!) to the ZX, which would alleviate a tendency for the occasional tank-slapper.
The ZX-6R sounds mean with its voracious intake roar, has no trouble pulling the R6 and CBR down a straight road, and its response when coming back into the throttle isn’t as abrupt as the previously mentioned pair.
“I felt very comfortable riding hard on this bike,” says MCUSA graphics dude Brian Chamberlain about the Kawasaki. “It has an awesome motor and stable handling. Only its ergos and its slightly slower steering hurt this bike.”
2004 Supersport Shootout
2004 Suzuki GSX-R600 Comaprison
2004 Yamaha YZF-R6 Comparison
2004 Honda CBR600RR Comparison
2004 Kawasaki ZX-6R Comparison
2004 Ducati 749 Comparison
2004 Supersport Shootout Conclusion