Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/128195
(Left) Dunlop's Dave Watkins talks tires with Eric Bostrom. 40 mph faster and running at sustained top speeds for that much longer. Keeping the throttle pinned through NASCAR three and four on the 1000cc Superbikes was an act of either bravado or stupidity. During the fall Formula USA/Championship Cup Series races, all the tire companies were humbled by the chicane, with unheard-of tire temperatures providing premature failures across the board, even though those races were all run on DOT tires. "When we were here in October, we had tire failures on tires that were previously deemed safe," Dunlop road race manager Jim Allen said. "They were overheating. The bikes are going faster for a longer period of time. They get to top speed sooner, and they stay there longer. I told [the Dunlop race team in Birmingham, England) what I knew, and they made tires to hopefully address that." The tires Dunlop makes for Daytona are good only at Daytona, though many of the riders will dispute that. Softer on the right side to handle the two infield horseshoes and the chicane, much harder on the right for the sustained g-forces on the banking and the longest throttle-open runs in racing, the tires are built for safety ahead of everything. including traction. They get better every year, but they'll never feel like a normal tire. Having been away for three years. Ben Bostrom had forgotten how little traction the Daytona dual-compounds offered. "I come here, I forget how slippery it is," he said. "You get on those tires and it's like you're on a set of bowling balls. At the end of the day, you feel like you're getting good drives out of there. I know I'm not; you just told yourself that." The testing process involves making tires fail. In addition to the allteams test in December, Dunlop brings a few riders to Daytona for a test in the heat of August, hoping to better duplicate the kind of conditions they might find in March. What they learned in August became almost worthless once the early results came in from the fall race weekend. Allen said that out of every 10 ideas, they might get one good one. This year, they did better. In the past, again than what we'd done in the past. When we did indoor wheel testings with the old joint system, we could make that joint fail on the test wheel at very high speed. When we tested the new system on the indoor test wheel, we did not get a failure there. We got a different failure. Ultimately, you test every tire to failure. The failure that we got wasn't unexpected considering the speeds. We didn't get the joint-integrity problem we had in the past." Three new rear compounds were brought in two different constructions from the Birmingham race shop. There were also four tire specifications from Japan. The UK rear tires, now 195/75, up from 190/60, are slightly wider with a stronger construction, which should allow them to run cooler. "On the drum testing, it looks like a better size," Allen said. Dunlop also brought three new front constructions. "For us to provide a safe tire in March, we need to get some track time," Allen said on the first rainedout day of the test. "It's going to be more complicated because we've got bikes we haven't seen yet." Those would be the new Suzuki GSX-R 1000 Superbikes. The concern was that the heavier and faster 1000s would be achieving higher top speeds, which may be true, though top speed has never been an issue. Getting to terminal velocity is the issue. "I think the biggest thing now is, they've opened up a can of worms on the banking, because essentially now you're changing into fifth gear right about where you were changing into fourth, maybe even a bit earlier," Yoshimura Suzuki's Mat Mladin said. "Like if your bike was revving to 15,000 rpm before, right now we're the dual-compound tires had failed along the seam between the two compounds. For this year's Daytona tires, Dunlop developed a radical new method of extruding the rubber onto the carcass, a method that strengthens that seam and makes it invisible. "We had some problems with the integrity of the circumferential joints between the compounds in March and again in August [at a separate Daytona test]," Allen said. "We made some modifications in both cases, both in March and August, and neither of them were 100-percent successful, so we had to come up with a new process to put the two compounds together entirely different Austin Ducat;'s Anthony Gobert was fast at the test, even though he was concentrating on race setup. eye' e n e vv so: