Just as the previous version of Kawasaki's ZZR600 was virtually identical to the ZX-6E, the 2005 Kawasaki ZZR600 looks to be a ringer for the 2000-2002 version of the ZX-6R. Here is our first ride piece for that bike, from the June 2000 issue of Sport Rider.
World press introductions held at a racetrack to showcase a manufacturer's latest sportbike are a funny thing. Anytime you bring motojournalists from different countries together and cut them loose on a world-class racing circuit, sooner or later national pride invariably works its way into the mix. Yes, we're there primarily to find a bike's limitations and report on its handling characteristics on the controlled and relatively safe confines of racetrack tarmac. But when someone loudly proclaims that his rider is four seconds a lap faster than "you Americans," things turn ugly; the hairs on the back of our necks stand up, our hides get chafed and we're forced to take up the cudgels.
When a certain, rather arrogant, European tire distributor at Kawasaki's press launch for its new 2000 ZX-6R made this particular boast to Kawasaki U.S.A.'s PR manager, Yankee ire was raised to new levels-bringing a normally mild-mannered fellow American motojournalist to utter the aforementioned "talking..." remark. The result? Under the watchful eye of Kawasaki technicians at the Circuito Ricardo Tormo in Valencia, Spain, the fellow American magazine staffer and I clipped on our "red mist" visors, and ended up circulating more than a full second under that tire distributor test rider's best lap time. That'll learn ya....
Good-natured chest-pounding aside, when Kawasaki's PR team originally informed us that they were planning a world press introduction for the new ZX-6R, we wondered why they were going through all the trouble. Judging from preliminary press kit information and scattered reports, Team Green's middleweight had undergone some minor tweaks to the engine along with new bodywork nearly identical to its bigger brethren; but no apparent redesign that would normally warrant this major international launch.
However, after a rather surprising tech briefing that revealed many additional changes to both the engine and chassis than we originally thought-and two days of furious racetrack apex-strafing with some street riding thrown in-it became obvious why Kawasaki decided to make such a big splash with its new ZX-6R. Team Green's latest 600 may not seem too different from the outside; but inside lurks a revitalized performance potential that just might boost the 6R to the top of the most hotly contested category in sportbikes. And that's worth pounding your chest about.
The ZX-6R's 599cc four-cylinder mill was never a slouch horsepower-wise-consistently ranking at or near the top of the class. Kawasaki engineers weren't satisfied, however, and redesigned numerous engine parts with an evolutionary-rather than revolutionary-eye toward increased power and less weight. The powerplant's basic configuration and construction remains the same, but many key components received a thorough re-examination in pursuit of those goals.
Key changes center around the cylinder head and top-end. Capping the list is a new semi-hemispherical combustion chamber (based on Kawasaki's WSB racebike...from 1996!) that boosts the compression ratio to a stratospheric 12.8:1, requiring at least 90 octane pump fuel for proper combustion. In the interests of increased top-end power, the carburetor manifolds were shortened 7mm, reducing overall port length; while the ram-air ducts were reshaped to increase airbox pressure at higher speeds by a claimed 12.0 percent.
Redesigned pistons slide through an all-aluminum, closed-deck, electroplated cylinder assembly; this not only cuts weight and provides improved wear resistance and heat dispersion, but also allows tighter piston/cylinder clearances for more power. Stronger connecting rods mate to a revised crankshaft that is 12.3 percent lighter, which-combined with a 7.0 percent lighter flywheel-is aimed at quicker acceleration. A myriad of other changes and improvements (more magnesium engine covers, integrated ignition coil/plug caps, lightened cams, thinner steel clutch plates and ram-air ducts, etc.) were aimed at cutting weight, resulting in a total engine package that not only cranks out three more horsepower, but also weighs a remarkable 7.7 pounds less than last year's motor.
The new all-aluminum, electroplated,...
The new all-aluminum, electroplated, closed-deck design cylinder (right) is not only stronger, sheds heat better (allowing tighter piston/cylinder clearance for more power) and is longer wearing, but also cuts weight by two pounds.
Impressive on paper, yes; but does the 6R's motor deliver? Numerous racetrack sessions and several hours on curvy Spanish roads were enough to convince us that it does-in spades.
Our initial fears that the new engine's modifications may have sacrificed some of the impressive midrange that made last year's Kawasaki such fun to ride proved to be unfounded. If anything, it seems as if the revisions bolstered the ZX's low-to-midrange acceleration. The throttle response is noticeably snappier, and the bike zips off from stoplights with unbridled enthusiasm. The meat of the powerband extends as low as 8000 rpm, which not only provides crisper acceleration off the line, but also allows the rider to maintain momentum through certain corner combinations by carrying a gear higher than normal-rather than expending time and concentration with more gear changes.
The new ZX-6R's more compact...
The new ZX-6R's more compact combustion chamber (above, left) is readily apparent-note the slight reconfiguration of the piston dome. The design comes straight from Kawasaki's 1996 ZX-7R WSB racebike.
The smooth transition to major thrust occurs around 9500 rpm, quickly wailing its way up to the power peak at 13,500 rpm, where the acceleration begins to tail off a bit. There's a little overrev capability available on up to the redline of 14,500 rpm, however. Although it's difficult to tell without a side-by-side comparison, our initial seat-of-the-pants impression is that the new ZX-6R's acceleration and speed is on par with Yamaha's YZF-R6, the winner of last year's SR 600 shootout (see June '99). And probably even more interesting is that the Kawasaki's handling now appears to be right up there too.
Overall chassis weight has been dropped by 3.3 pounds through revisions to the suspension, the swingarm material, and a thinner instrument panel. (All told, the new ZX-6R is claimed to weigh 11.0 pounds less than last year.) But the big news is centered around the front end geometry change and the revamped suspension's spring and damping rates. In an effort to gain front end feedback, Kawasaki engineers increased the fork pitch (the distance between fork tubes) 5mm, and reduced fork offset from 30mm to 28mm for more trail. Combined with stiffer springs front and back, plus new damping rates working with a more progressive shock linkage in the rear, the new 6R's chassis exhibits a far more controlled and stable feel on the track and the road. The Valencia circuit's relatively new pavement lacks the bumps to really put the suspension through its paces at ultra-elevated speeds, but the gnarly condition of the surrounding Spanish roads we traversed during our spirited street ride proved the Kawasaki's chassis is up to the task at sane riding levels.
A lot of little detail changes...
A lot of little detail changes add up in the bike's overall weight savings-such as the new model's smaller and thinner instrument panel on the left.
Steering feel and tire feedback during banzai corner entries on the track were much improved-with none of the slightly numb feeling we experienced on the Kawasaki's previous model. Turn-in was as crisp as ever, and line changes could be easily accomplished midcorner without much effort. And virtually none of these assets changed with a switch to race compound tires; several ZX-6Rs were equipped with Dunlop D207GP Star production race tires during the latter half of the racetrack testing (when we had to silence the arrogant Euro tire distributor), and were hammered mercilessly with no ill effects other than a slight loss of straight line stability.
Another welcome change we noticed immediately was the upgraded front brakes. The calipers now sport differing piston sizes for more even pad wear, but we suspect the major reason for the brake's vastly improved power and modulation over the previous year's wooden-feeling binders is a change in brake pad compound. The new ZX-6R's brakes allow super-deep corner entries with confidence, providing excellent feel up to the point of tire lockup.
A cross-section comparison...
A cross-section comparison of the new (left) and old (right) swingarm construction shows the new internal bracing of the pentagonal box-section design. This allows additional strength while shedding some weight.
Thankfully, one item Kawasaki hasn't changed is the bike's excellent ergonomics. Although the clip-ons now mount below the triple clamps (permitting shorter fork tubes and reducing overall weight), the riding position feels nearly identical to last year; there's still plenty of legroom, and the seat gives great support for those highway drones. The new front fairing is more aggressive aerodynamically, yet the windscreen is 5mm taller for a bit more wind protection; and the mirrors give a decent rearward view. The engine is still silky-smooth at highway cruising speeds, with only the slightest tingle through the pegs at 6000 rpm.
So Kawasaki pulled another fast one on us. While the bike seemed to be nothing more than a dressed-up version of last year's highly competent model, at first glance, one ride was enough to convince us that Team Green's engineers haven't been sitting around twiddling their thumbs. The latest ZX-6R-improved in the few weak spots that we felt held it back compared to its competition-looks ready to battle for the top spot. We can hardly wait for this year's 600 shootout to begin.
This article was originally published in the June 2000 issue of Sport Rider.
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