Z X - 6 R R
Z X - 6 R R
RR stands for "Race-Ready"
Impressive motorcycle, the 2003 Kawasaki ZX-6R, on both street and track. Only thing is, its 636cc displacement means that, technically, it’s not a 600. It’s one thing to include it in a magazine comparison test, but quite another when it comes to Supersport racing, where class rules mandate 600cc max for four-cylinders.
That’s where the $8399 ZX-6RR comes in. Based on the standard single-R model, the limited-production double-R gets by with a 599cc mill that makes 6 fewer horsepower (98 bhp at the rear wheel compared to the 636’s 104 ponies) and noticeably less midrange torque; below 10,000 rpm, there’s nobody home.
As befits its racing intent, the RR is endowed with a few extras such as lightweight forged (rather than cast) pistons, a back-torquelimiting clutch, adjustable swingarm pivot and a threaded frame boss to accept a steering damper. Also, like the base Rmodel, the RR’s rear ride height is adjustable via 1mm shims. None of this chassis trickery mattered to us at California Speedway, however, as the required shims and pivot plates were apparently still on a boat bound for Long Beach. Truth be told, Kawasaki wasn’t overly happy to provide us with an RR.
The bikes will be imported in limited numbers, the main focus being the 636, and the one test unit available was a little tired, hence the mandate not to street ride it, dragstrip it or get it anywhere near a dyno, never mind those stipulations doomed the bike to sidebar fodder. (Towards the end of our test, a new RR was broken loose, too late for inclusion, but at least we got horsepower figures).
Even with the problems, once on track, the RR made a good accounting of itself. Assistant Editor Mark Cernicky was the most vocal (a not uncommon scenario, incidentally), praising the green bike’s weightless transitions and willingness to trail-brake deep into corners. Veteran Road Test Editor Don Canet was a bit more reserved, saying, “Pretty much everything we noted about the 636 applies here. Although the two bikes’ chassis are the same, the RR’s seems slightly more settled, and its engine feels less coarse. And its slipper clutch allowed smooth, deep corner entries.”
Not all was perfect, however, as Canet attests. “The RR gave me a big moment when it broke into a vicious headshake through the fast infield chicane,” he said. “Tankslappers while you’re leaned over are not fun!”
In the end, the ZX-6RR’s onboard lap timer showed a best circuit at 1:36.1-fourth quickest of the seven middleweights on hand, and less than a second off the pace set by the Yamaha YZF-R6. In the hunt. And with its suspension fully sorted-and a steering damper bolted in place-it will only get better. -Brian Catterson
