Cycle News - Archive Issues - 2000's

DUNLOP'S NEWEST RUBBER IS FIT FOR THE TRACK Q, in racer talk, as in, "Hey, Mick, throw in a Q") is Dunlop's answer to the high-performance street tire, aimed at what it calls its "serious riders." To show just how serious it is, Dunlop rented the Spring Mountain Motorsports Park, better known as Pahrump, a rugged little racetrack located roughly an hour's drive from Las Vegas. Pahrump has it all: tight, technical sections of pavement combined with high-speed corners and a dose of off-camber stuff thrown in just to keep things interesting. The thought process behind introducing a street tire at a racetrack is simple: If it works at the track, it's going to work on the street. A good idea if the tire is good. A recipe for disaster if it's not. After all, a few quick laps on a standard street tire will usually result in the tire getting hot. Then it starts sliding around like a sun-screened fat man on a waterslide. And that's exactly happened. But it happened with the D20B, the tire that the Qualifier is replacing. What? Okay, since the boys at Dunlop weren't born yesterday, they knew there was no better way to show off its newest tire than to compare it with the old. So for the first half-day of a two-day test, D20Bs were fitted to the quiver of sportbikes that were on hand (Yamaha R6s, RIs, CBR IOOORRs, CBR600s, Kawasaki 636s, Suzuki GSX-RIOOOs... drooling yet?). Sure enough, it didn't take long for the 20Bs to get a bit greasy and start sliding around. So how did its replacement do? Patience, my friends. First we have to discuss carcass plies, aramid belts and polymers. To ensure that the Qualifier had better grip than the D20B, Dunlop went to a com- pound they know works - a similar mix to the one found on the Sportmax GP race tire, one of the most successful Supersport tires ever made. With a blend of three polymers, the Q was deSigned to offer grip (both wet and dry) and durability. Not quite a race tire, but the next-best thing. For the rear, Dunlop didn't change the profile much over the 20B, so the biggest change there is to the compound. Not so for the front, however, as the engineers went more along the lines of the Sportmax GP for its profile, and the result is a more triangulated tire. With the profile changed rather drastically, the compound wasn't, and it's basically unchanged from the 20B sort of the polar opposite of what they opted to do with the rear. Dunlop has three development plants in the world - Japan, England and Buffalo, New York - and the Qualifier combines the work of all three, according to Dunlop. While the front tire's profile is the product of Dunlop's British race-tire group, the thread pattern of both tires was a joint The rear features a continuously wound tread belt (to keep the tire diameter consistent, not growing at speed); in the IBOs and 190s, the tires use one-nylon carcass ply and one aramid JLB (jointless band) belt while the 200 has two-nylon carcass ply and one aramid belt. Although street tires have to have tread patterns just in case it rains, the less the better - as far as grip goes. The Qualifier's tread pattern closely resembles the one found on the Sportmax Gp, though the Q's are longer to better displace water. With test riders such as Danny Roberts and Rich Conincelli at the controls, "H EY, around after just a handful of laps, that wasn't the case with the Qualifiers. Certainly there were those among us who could get the tire hot enough to slide around, but it was after at least twice as many laps as the 20Bs. The rear Qualifier has better side grip and better traction, which translates into a drop in lap times. What else do you want? But perhaps the most impressive thing about the new Qualifiers is the front tire. The new profile allows for easier turn-in, yet it doesn't give up anything on stability either with straight line or trail braking. There's one portion of the Pahrump track where this showed - the downhill left, right, left set of esses. Through there the new front was magic, allowing the bike (no matter which bike) to flick from side to side easier - and prOViding better feel and input the entire time. MICK, THROW IN A Dunlop did heaps of testing with the Qualifier, using on-board diagnostic equipment to better chase the tire they were looking for. When they'd found the perfect compound, tread pattern and profile, they took the tires to Virginia International Raceway. There they found the Qualifier to be 3.5 seconds per lap qUicker than the D20B that it was replacing. Though we didn't have stopwatches on us at Pahrump (thank God!), it was easy to see after riding on the D20Bs that the Qualifier is simply a better tire - in every facet. For one, it has more grip. And that grip lasts longer. While the D20Bs were sliding Dunlop claims that the new Qualifier heats up qUicker than the D20B, and I'll take their word for it. After crashing a few years ago on a cold tire, I'm careful to a fault with any tire for at least two laps. Dunlop also claims that the Qualifier doesn't give up anything to the D20B as far as tread life is concerned. Again, without the benefit of putting in some serious miles on the street with the new tire, we have to take them on their word. The new Qualifier, the street-going equivalent of the Sportmax GP tire, will be available in January 2006, according to Dunlop. "What we set out to do was build a street tire out ~f a race tire," said Dunlop motorcycle product development manager Mick Jackson. eN Mission accomplished. effort between engineers in Japan Buffalo. The object of the new profile of tires was to increase the contact With the front tire, the triangulated allows for more of the tire to be on road. With the rear, the change in compound allows the tire to have less tread (and a bigger contact patch) yet still maintain the wet-weather grip that the 20B had. Dunlop says the front tire's "land area" has increased 6 percent, with the rear getting a "land area" increase of 3.4 percent over the D20B. The front tire's construction uses nylon carcass plies and two aramid belts. CYCLE NEWS • NOVEMBER 23, 2005 31

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