It's War! Supersport Stunners For 2003!
IT'S WAR! SUPERSPORT STUNNERS FOR 2003!
ROUNDUP
WIN ON SUNDAY, SELL on Monday? You bet, especially in the ultra-competitive world of AMA Supersport racing. Honda, Kawasaki and Yamaha all came up short this year, having fallen prey to the Suzuki GSX-R600 of hard-charging Aaron Yates. No surprise, at least two of the three also-rans will field brand-new machinery in 2003.
Kawasaki was first to show its hand. The ZX-6RR is a stem-tostem re-do, with a more compact, fuel-injected four-cylinder engine that revs to 16,000 rpm and breathes through a single, centrally located, through-the-ffame ram-air duct. The claimed sub400-pound repli-racer is the first bike in the class to have an inverted fork and the first production motorcycle to wear radial front brake calipers.
Displacement remains 599cc, but bore is 1.0mm larger and stroke is 1.3mm shorter. Actual dimensions are 67.0 x 42.5mm. Other mods? Forged-aluminum pistons weigh 5 grams less than the old-style ZX-6R slugs, cams have less lift, are lighter and slotted for adjustability, and there’s 15 percent more crankshaft inertia. As for the gearbox, first and second ratios are unchanged, while third through sixth were snugged up. New, too, is a slipper clutch. Racy!
In addition to a redesigned twin-spar aluminum frame, beefier triple-clamps and fully adjustable Kayaba suspension, the big news in the chassis department is an adjustable swingarm pivot-just like the factory Superbikes! Significantly more rigid than the conventionally mounted six-pot calipers they replace, the all-new Tokico binders feature four 32mm pistons and individual pads. Discs are thicker, carriers are no longer offset and lines are simplified. A single finger is all you’ll need, we’re told. Out back, leverage was tweaked for better feel.
All-new controls and bodywork give the RR more trackoriented ergonomics and a decidedly more aggressive stance similar to that of the ZXRR MotoGP prototype currently being raced in Japan. Instrumentation is fully liquid crystal, with tachometer, speedometer, stopwatch, lap-counter and adjustable shift light all contained within a single compact unit.
Over at Yamaha, the YZF-R6 has gone through a similar shakeup. Fuel-injection-the same hybrid carb-like CV setup used on the Rl, but with smaller 38mm throttle bodies-leads the long list of engine changes. Visually, the engine looks identical, but new cases reduce pumping losses and better handle newfound power. Bore and stroke are untouched, while new pistons, a hotter spark, higherlift cams, friction-cutting crank bearings and an aluminumsleeved muffler with titanium internals to offset the addition of an emissions-meeting catalyzer hoist claimed output to 117 horsepower at the crank.
Yamaha’s controlled-fill casting technology (Roundup, October) helped to reduce welds on the new black-painted Deltabox III frame from 16 to two. The subframe and sculpted asymmetrical swingarm got the C-F treatment, as well. Overall chassis rigidity is up 50 percent, to levels “approaching that of the R7 Superbike.” Wheelbase remains 54.3 inches, but the countershaft is 10mm closer to the swingarm pivot. The swingarm itself is 10mm longer than before. Fork offset was reduced 5mm. Claimed dry weight for the entire bike is 357 pounds, which is 8 pounds less than the ’02 model. Colors are blue, silver or, for a $100 premium, black with red flames.
Honda, meanwhile, isn’t saying much, its PR-types’ lips pinched tighter than the ratios in the ZX-6RR’s tranny. Still, rumors persist of an edgy, MotoGPinspired super-middleweight, capped by an RC211 V-esque underseat muffler. Postulating aside, it is time for a change. The CBR600F4Í is two years old, after all...
The lines are drawn. Let the battle begin! Matthew Miles
