We fitted our Supersports with Dunlop's sticky new D208GP-JLB tires. They held up through a track day and a couple quarter-mile runs, and remained predictable the entire time.
When it comes down to speaking of how a bike performs on a racetrack, the real crucible is the stopwatch. Or, in our case, our snazzy
Vbox data logger.
Before hitting the track, we fitted each bike with identical sets of race-compound rubber so we'd be testing bikes and not different tires. We called up
Dunlop to order several sets of its D208GP-JLB that debuted just a few months ago (not to be confused with the brand-new multi-compound Sportmax GP that was announced at Daytona a few weeks ago).
This is a new version of Dunlop's D208GP supersport tire that is developed and manufactured in the USA. The "JLB" suffix is an acronym for Dunlop's Jointless Band construction, something it uses in its rear tire for "top-level traction, rider-friendly set-up and exceptionally responsive turning characteristics." Dunlop says the tire's new construction delivers an improved ability to yield to bumpy pavement, and it claims it's more neutral steering to allow fine changes to a racer's line through the corners.
Once past the tires' slippery stage while scrubbing them in, the
Dunlops didn't cease to impress.
"They seemed to heat up quickly and the grip was excellent throughout the day," says Becklin, a former racer who has been on countless sets of race rubber. "I always felt comfortable flicking the bikes on their sides with these tires under me. Even when the laps were piling up, the 208GPs just kept sticking."
Our gang praised the Dunlops' grip and the amount of feedback offered. We've tested several brands of race-compound tires in the past including previous Dunlops but at least one of us thinks these new buns might be the best yet.
"Compared to the other track tires we have used on the track and at shootouts, I'd rate the Dunlop D208GPs at the top of the list," Becklin says assuredly. "When the tires did break traction, they slid predictably. This gives you confidence to push hard, knowing you'd get some warning before they let go. Confidence-inspiring is the term that comes to mind. I'm not sure if it's the fact that these tires are now made in the U.S. or that there are changes in compound or construction, but they work great."
We decided to wait until Thunderhill to run lap times because the GSX-R wasn't on equal "footing" at Infineon Raceway. Those who haven't been to
Thunderhill before are missing out on a fun and challenging track. Located north of Sacramento, the 3.0-mile track's most entertaining feature is its couple of elevation changes that sweep up and down the area's rolling hills. And unlike the smooth surface of Infineon, T-Hill's gnarly asphalt is a real test of how well a suspension works at speed. The track has had as many surface reconstructions as Cher.
The ZX looks good even when it's standing still. A new and improved design helps the aesthetically challenged Zixxer of the last two years.
We were at Thunderhill as guests of the friendly and helpful guys at
Pacific Track Time, and we spent the better part of the day circulating the track without pushing for quick lap times, busy as we were with gathering video, taking notes, setting up bikes and trying not to crash. I was eventually fitted with the Vbox mid-afternoon as traffic began to dwindle and was sent out to run at least four clean laps of data on each bike. We'd be logging not only lap times but also the actual maximum speed (not the numbers on the highly inaccurate stock speedometers) attained at the end of Thunderhill's front straight.
This would be a tough task. Not only would I be trying to avoid slower riders on the track, I'd be doing it while trying for the first time all day to cut some laps as quick as I dared. My internal stopwatch told me I was quickest on the ZX and R6, so I decided to take them out first in case they might've had an unfair advantage by going out with more fast laps under my belt. Here's how it shook out.
Thunderhill Fastest Lap Times
1. Kawasaki ZX-6R: 2:14.6
Even though I went out on it first, the mighty ZX prevailed in this contest. Aided by strong brakes, reasonably light steering, admirable mid-corner stability and its enviable slipper clutch, the Kawasaki stomped the smaller bikes at Thunderhill. There are a couple of sections of track such as the uphill climb from Turn 8 to Turn 9 that the 6R is noticeably faster. Its speed at the end of the front straight, 136.1 mph was the fastest of the group.
2. Yamaha YZF-R6: 2:15.5
The Yamaha's speed at the end of the front straight gives a bit of a clue why it was the quickest 600 on this day. The R6 logged a highly creditable 133.7 mph, second only to the big ZX. A high trap speed means there's more acceleration at hand, and the R6's lower gearing and wailing top end gets down the road quicker than the other 600s.
3. Suzuki GSX-R600: 2:16.9
Although the Gixxer's chassis feels solid and its steering damper calms its bars at speed, the Suzi didn't inspire confidence in us quite like the others. Its midrange lunge helps it pick up time on the CBR, but only just barely, and its trap speed of 129.7 mph was the slowest.
4. Honda CBR600RR: 2:17.2
It basically comes down to the motor, folks. Even though I was no longer braking for the high-speed Turn 8 like I was on the ZX and R6, it wasn't enough to gain back what it lost on the straights. At Infineon, a venue that doesn't have long periods of full-throttle acceleration like Thunderhill, we're sure the CBR was capable of running right with the quickest. Its trap speed on the front straight of 131.1 mph is testimony to its high corner speed on the exit of the final turn.
