"Q" For the Street
"Q" FOR THE STREET
DUNLOP CLAIMS THAT around Virginia International Raceway's 1.65-mile South Course, the new Sportmax Qualifier is 3.5 seconds per lap quicker than its current high-performance street radial, the D208 ZR. Spokesmen also say that the "Q" is a step forward in warm-up, grip, feedback and durability for about the same MSRP of $375 a set. Great, except I wasn't at VIR. Rather, I was at Spring Mountain Motorsports Park in Pahrump, Nevada, site of the Qualifier's press launch. For the technical side of the story, Dunlop pulled out its heavy artillery, Motorcycle Development Manager Mick Jackson. "We set out to build a street tire out of a race tire," he explained, referring to the Sportmax GP, the DOTapproved race tire launched last year at Daytona.
Triangular in profile for quicker tum-in, the GP-esque front Q uses two nylon carcass plies and two aramid reinforcing belts. The rear retains the profile of the ZR, with a single nylon and a single aramid belt in the 180 and 190mm sizes, and two nylon and one aramid in the 200mm dimension. Jointless-band construction-a continuously wound tread belt-controls growth at speed.
Construction is straightforward compared to the black art of compounding. The front is “quite close” to the D208 GP, said Jackson. More surface area-the result of using a finer carbon black-is key to
improved performance, noted another engineer. “The rear-a blend of three polymers reinforced with a highsurface-area carbon black and a proprietary resin to maximize durability and wet and dry grip-is similar to the medium-traction material found in our Sportmax GP,” added Jackson. Deep voids and more “longitudinal elements” in the center of the tread up wet-weather traction.
Tech briefing complete, journalists were turned loose on the racetrack, first on the old D208 ZR, then the new Qualifier. Dunlop had both middleweight and Open-class bikes on hand, but I stuck with the bigger models because of the extra stresses they put on a tire. The front Q offered consistently excellent grip and a profile that encourages racing-mandatory trailbraking. It wasn’t until I got on a race-prepped Kawasaki ZX-10R, however, that I was able to get near the rear tire’s limits and adjust grip with the throttle, at a pace I never reached on the stock bikes.
Because the introduction was held in late October, ambient temperature at Spring Mountain was just 70 degrees. Having tested high-performance street tires in 1 OO-plus-degree heat, I can vouch that it’s in those elevated temperatures where race rubber has an advantage (especially in terms of rear side grip) over street
tires. In less-thanHades-hot conditions, though, the rails. -Nick Ienatsch
