Kawasaki: 87.8
"The Kawasaki has all the ingredients but is woefully lacking in motor," noted El Jefe after logging the slowest lap time on the ZX-6R. The Kawasaki-despite being the heaviest bike here-drew favorable comments from our testers for its handling and overall manners, but it notched the lowest scores for engine power and engine power delivery, leaving it well back of its Japanese rivals in overall track scores. "The Kawasaki just felt like my favorite pair of slippers, and I was immediately comfortable on it," noted Siahaan once we roused him from his afternoon nap. The ZX-6R's chassis is characterized by neutral, light steering, crisp, progressive brakes and stiff but compliant suspension, and everyone felt immediately comfortable on the green bike. Even with its stretched-out riding position it scored highest in the ergonomics category. Ironically the Kawasaki is the only bike here without a steering damper, yet stability over Buttonwillow's rough surface was very good.
Unfortunately that user-friendly chassis is more than let down by an uninspiring engine that has been neutered of its full potential (see the sidebar on page 62 for details on how simply connecting two wires in the Kawasaki's harness unleashes a full six more horsepower that lurks inside the ZX-6R's ECU). While the Kawasaki's rev ceiling is just as cathedral-ceiling high as the Honda's and Suzuki's, peak power occurs at just 12,000 rpm-about on par with the lower-revving 675 triple-leaving acres of mostly unusable overrev. What's really a shame is that the Kawasaki's power is perhaps the most easily accessible of this bunch: The excellent slipper clutch lets you run deep into corners without worrying about precise downshifting, and the off/on throttle transition from the dual-injector, dual-butterfly setup is buttery-smooth. This left our testers divided on scores and comments about the bike's performance, as some felt the forgiving chassis and usable engine deserved high marks while others noted that the low power dominated overall performance.
Kawasaki ZX-6R
Test Notes
+ Agile yet stable on street or track
+ Well-sorted details make it fun to ride
- Way underpowered-and then some
- Heaviest bike in the class
x But for a short piece of wire...
Suggested Suspension Settings
Front Spring preload: 10 turns out from full stiff; rebound damping: 1.5 turns out from full stiff; compression damping: 2 turns out from full stiff; ride height: 13mm fork tube showing above triple clamp
Rear Spring preload: 8mm thread showing; rebound damping: 15 clicks out from full stiff; low-speed compression damping: 2 turns out from full stiff; high-speed compression damping: 2.5 turns out from full stiff
Suzuki: 89.2
Posting middle-of-the-road scores across the board along with the third-quickest lap time, the new-for-2008 GSX-R600 earned third spot in the track rankings. Similar to the Kawasaki's situation, the Suzuki combines a great chassis with an engine that still lacks steam compared with the class leaders. The highlights of the GSX-R's chassis are its plush yet firm suspension and updated brakes, a significant improvement from the old model's fade-prone binders. Feedback from the chassis is outstanding, and the ergonomic package rated highly among our riders. "Still the ultimate chassis in terms of confidence-inspiring feedback and front-end feel. It's positively telepathic," raved Holst. While the potbellied-pig lover (that dash is crucial, no?) and other testers found little fault with the Suzuki's chassis, others were not so keen. "The Suzuki feels heavier and turns slower than the R6 no matter how much muscle you use," wrote glass-half-empty Trevitt.
Just three pounds lighter than the potbellied ZX-6R, the equally porky Suzuki is not helped by an engine as dull as Barry Manilow night on American Idol compared with the Honda's and Yamaha's spunky mills. While response from the dual-butterfly, dual-injector SDTV is smooth and the GSX-R pulls hard off the corners with much more midrange than its predecessor, top-end power is lacking in this company. This somewhat contradicts the dyno chart that shows the Suzuki posting the second-highest peak horsepower figure and a strong torque curve across the range, but the explanation may be found in the 600's tall gearing and its throttle setup. Past GSX-R models have had elliptical throttle-cable cams that give a disproportionate relationship between the throttle tube and butterflies. This relationship seems exaggerated on the new GSX-R600, with the last few degrees of rotation resulting in a huge jump in power-and it doesn't help that the long-turn throttle requires those with small hands to regrip on corner exits. It may seem like a simple and obvious oversight to not use full throttle, but you'd be surprised at the number of riders we observe on data traces doing just that on any of the GSX-R models.
Suzuki GSX-R600
Test Notes
+ More muscular engine
+ Fantastic chassis verges on magical
- Still down on steam
- Still overweight
x OEM tires make up for a lot
Suggested Suspension Settings
Front Spring preload: 8 turns out from full stiff; rebound damping: 1 turn out from full stiff; compression damping: 2 turns out from full stiff; ride height: 5mm fork tube showing above triple clamp
Rear Spring preload: 8mm thread showing; rebound damping: 2.5 turns out from full stiff; low-speed compression damping: 1.5 turns out from full stiff; high-speed compression damping: 3 turns out from full stiff