Four of A Kind

Four of a Kind

CW COMPARISON

Honda CBR600RR vs. Kawasaki ZX-6RR vs. Suzuki GSX-R600 vs. Yamaha YZF-R6

MARK CERNICKY

WE WERE DOOMED FROM THE START. THERE’S NEVER ENOUGH LIGHT IN THE day, let alone time in a month, to poke, prod and pull all the potential from sportbikes like these four Sixes.

In last year’s “Splitting Hairs” comparison test (CW, May, 2003), Yamaha’s YZF-R6 was judged the finest. The closed-course portion of our testing took place at California Speedway, the same place Jamie Hacking aboard the factory YZF-R6 started a drive that took him to the 2003 AMA Supersport series national championship, a pretty strong seconding of our choice of the Yamaha as Best Middleweight Sportbike.

This year, CW staffers once again put the Four of a Kind through their paces, including cannonball commuting, blasting up and down our favorite backroads and rounding as many comers as we could turn up, because that’s what 600s do best. Like last year, our dragstrip testing was performed at California Speedway’s quarter-mile, but our road-course work this time was conducted in conjunction with a HyperClub track day (www.hypercycle.com) at the Streets of Willow Springs.

Unlike Cal-Speedway’s long, high-speed straightaways and smooth infield comers with their deliberate braking and tum-in points, the Streets circuit features numerous comer irregularities requiring profuse amounts of trailand/or transitional braking, and requiring technical mid-throttle operation. Diverse pavement anomalies such as slurry-seal snakes, washboard ripples, big and little bumps dot the circuit, adding to the challenge.

Dubbed the “Six of Spades” for its rakish good looks, the Yamaha R6 has a very communicative but quick-steering chassis, making it the most nervous over the glut of bumps found at the Streets. Characteristically, the R6 fell into comers, and preferred that riders flicked it to full lean angle rather than employing old-school arcing techniques. With the stock tires limiting traction, we had to anticipate this action, punctually opening the throttle to save the front end from washing away. With the increased grip of race rubber, the Yamaha would likely be a lot more fun to ride at the Streets; as is, it never truly felt at home there. Bonus points for plentiful power, positive clutchless upshifts and slender feel between the knees, though nobody liked its chintzy clutch feel.

Kawasaki’s limited-edition ZX-6RR, the “Six of Diamonds,” is far better facetted this year. Its quartet of 38mm throttle bodies received secondary injectors to feed the new larger intake valves, now held open by a bumpier cam profile. Smaller, reshaped intake ports increase mixture velocity, further filling the redone combustion chambers. A new piston-crown shape with side-cut skirts received a molybdenum coating, reducing friction on this highrevver’s return stroke. As a result, the ’04 ZX-6RR makes as much power as did the 636cc ZX-6R sent through our hair-splitter in ’03.

The revised ratios in the RR’s six-speed gearbox allowed us to feed its 13-15,000-rpm rev-thirst. The suspension was a bit coarse on the street and at the Streets, but with some adjustments the Kawi became a diamond in the rough and turned the quickest laps of our test-a full second quicker than the next bike! Supple power delivery, glitch-free fuelinjection and its trick slipper-clutch made for flawless rpm& matching, critical while downshifting and braking into comers. With its onboard lap* timer, and adjustable ride height and swingarm \r pivot, the RR will be appreciated by race-rats who will have lots of fun playing around with set-up options. Street riders, however, will likely complain about the tallish first gear and soft low-end power.

Honda’s likeable CBR600RR is the “Six of Hearts.” Its solid, stable chassis and smooth, generous power instill confidence in any rider; your pants’ seat tells you that you’re leaving corners rapidly because you are! The suspension is the best of this bunch, providing the rider with direct feedback while damping surface imperfections that we wouldn't even have known were there if we hadn't ridden the other bikes. While the CBR is very neutral-steering, it takes more effort to change direction, probably because it weighs almost 30 pounds more than the others. It doesn’t have the strongest brakes, either, but front-end feel is good on decel, letting the rider know exactly what is transpiring at the contact patch.

Aside from having the highest passenger perch, the CBR is the most comfortable and user-friendly on the street. To find something really wrong with this bike, you have to look pretty hard.

Suzuki’s hard-hitting GSX-R600 is the “Six of Clubs.” With the most midrange grunt of this lot, it accelerated out of second-gear comers with more authority, giving us a choice of two ratios in some sections of the Streets. It was also the only bike to break into the 10s at the dragstrip.

In fast or slow bumpy comers, steering remained neutral, light and lively feeling. But not too lively-the Suzuki is the only Six with a steering damper. It carries its weight with an unbiased feeling front to rear, and its cockpit is easy to move around on/in, making incremental weight transfer possible when need be. Plus, its front brakes are incredible.

“Probably the best I’ve ever sampled,” remarked Executive Editor Brian Catterson.

Almost as powerful as the Honda, sharp-edged as the Kawasaki and quick-turning as the Yamaha, the Suzuki blends the best characteristics of the other three into one tidy package. Said Online Editor Calvin Kim, “The YZF felt like it was more for experts, the CBR was easiest to ride and I could just go on the ZX-6RR, but the GSX-R fit like a glove and feels like it can do no wrong.”

In the high-stakes game of Supersport racing, winners and losers are sometimes determined by the luck of the draw. In its winning hand. Suzuki’s new GSX-R600 holds the trump card.

HONDA

CBR600RR

$8599

SUZUKI

GSX-R600

$8099

KAWASAKI

ZX-6RR

$8399

YAMAHA

YZF-R6

$8099