Factory-supported Yamaha rider is enjoying the benefits of the narrower rear slick tire
This past June at Utah Motorsports Campus, MotoAmerica spec-tire-supplier Dunlop introduced a 180/60-17 KR451 rear tire for the Supersport class that replaced the previous 200/55-17 Superbike-issue slick. The new tire is designed to fit the 5.5-inch-wide wheel commonly used on middleweight sportbikes.
Since that time, defending Supersport champ and current points leader Garrett Gerloff has gone on a tear, winning five consecutive races. On Friday at New Jersey Motorsports Park, I asked the 22-year-old factory-supported Yamaha rider what role, if any, the tire has played in his performance.
“With the 200, we weren’t utilizing all of the tire,” Gerloff began. “We had what they call ‘chicken strips’ on the edges because the tire was rolled over on the rim. That made our contact patch smaller. By going to a smaller tire that fits the rim correctly, we are able to use the whole tire.
“When we are leaned over, we have more contact area, which has helped me carry more mid-corner speed. It also added a lot of consistency in the tire. When I get on the throttle while leaned over, there is a lot more control. The 200 would sometimes ‘snap’ on me when I would try to get on the throttle toward the end of a race.”
Because he can carry more corner speed, Gerloff doesn’t have to go to the throttle as early or hard as he once did. “So you are taking less risk, going faster, and it actually saves the tire a little bit more for the end of the race,” he said. “Sliding and all of those movements wear out the tire faster. The new tire is super-consistent. It drops off, but the steps are more subtle.”
This new tire has also impacted chassis setup. Gerloff says he now has better “feel” for what his Yamaha is doing on the track. “When I am able to ride more comfortably,” he said, “I am able to feel more of what is happening with the bike and set up the bike better to go faster. It is not just one thing; it is a chain of events.”
Gerloff says he is not a one-tricky pony. “I can ride a point-and-shoot bike,” he emphasized. “What has made it tough for me is that I am a heavier rider. I weigh 30 pounds more or less than [teammate] JD Beach. Even though I am on a strict diet and training program, I am as light as I can be. When I left home a couple of weeks ago, I had 6.5 percent body fat.
“JD and I are on the same bike. Last year, when I couldn’t carry corner speed, I lost time no matter what because my bike couldn’t accelerate as hard as his bike. Yes, I have some aero advantages, so at the end of long straightaways, I can have a higher top speed, but that doesn’t help me at places like New Jersey or other tighter tracks.
“JD was able to get into the corner, stop, point, and shoot out. I had to do the same thing, but I would lose time every corner of every lap. I think this tire has leveled out everything. You can ride this tire point and shoot, no problem. But you can also ride it a different way—the way I am able to now ride it. That is how the new tire has helped me.”