Indianapolis MotoGP Tire Analysis with Bridgestone’s Masao Azuma
Repsol Honda’s Marc Marquez won his 10th consecutive MotoGP series event out of 10 events Sunday at a revamped Indianapolis Motor Speedway.
Movistar Yamaha MotoGP duo of Jorge Lorenzo and Valentino Rossi finished second and third place respectively. Marquez is the reigning MotoGP World Champion, and both Lorenzo and Rossi have won multiple world titles – Lorenzo two and Rossi nine.
Conditions at race time were warm and dry with a peak track temperature of 48°C (118.4° F). All competitors but one of the 23 riders opted for the harder rear slick tire, and all except two went with the medium compound front slick, which was a new allocation option this year in response to the improved pace possible on the new Indianapolis circuit and warm track temperatures.
The compounds available were:
Bridgestone slick compounds available: Front: Soft, Medium & Hard; Rear: Soft, Medium & Hard (Asymmetric)
Bridgestone wet tire compounds available: Soft (Main), Hard (Alternative)
Following is a Q&A with Masao Azuma, Chief Engineer, Bridgestone Motorcycle Tire Development Department, who provides some in-depth MotoGP tire analysis.
Q. How did Bridgestone approach this year’s Indianapolis Grand Prix, given the new track layout and tarmac that made its debut in 2014?
MA: “The new layout features more open corners and the new tarmac has better grip and consistency, but the general characteristic of the Indianapolis circuit is still the same as it was before. There are a lot of acceleration and braking zones, but the most stressful part of the circuit for the tires are still the linked, left-handed corners from turns twelve to fourteen. So the tire development for Indianapolis this year wasn’t vastly different to previous years, we just provided an extra choice of front slick tire, the medium compound, and had to make sure our whole tire allocation could deal with the improved pace the new circuit would provide.”
Q. The new Indianapolis circuit is slightly shorter but considerably faster as the pace was over five second a lap quicker than last year. How much extra stress did this place on the tires?
MA: “The much quicker pace this year at IMS did make the track more severe for tires, but not to an extreme level. The extra grip of the tarmac and change to the layout resulted in higher cornering speeds in some sections, which in turn resulted in higher loads being placed on our tires.
“Some riders experienced high tire wear early in the race weekend, but this is usually the case on new, high-grip surfaces which don’t have much rubber laid down on them. As the race weekend progressed, both the performance and durability of our tires improved and during the race the riders said tire performance over race distance was very consistent. Overall, our tire allocation at Indianapolis was more than able to meet the demands of the new Indianapolis circuit.”
Q. Almost every rider selected the medium compound front slick for the race, even though track temperatures were considerably warmer on race day. What is it about that option of tire that made it so appealing to the riders?
MA: “Last year we brought just two front slick options to Indianapolis; the soft and hard compound. The soft compound front slick offers the better cornering performance, but doesn’t have the braking stability and durability of the hard compound front.
“The medium compound front slick we provided for the first time at Indianapolis this year combined good cornering performance with a high level of braking stability and most riders felt it was the best all-round performer on the new circuit. Given the track temperatures we had earlier in the race weekend were cooler than Sunday, many riders didn’t take the opportunity to test the hard compound front slick and even in the warmer temperatures on Sunday, didn’t want to take the chance of trying an untested front tire for the race.
“I believe if more riders had tested the hard compound front slick during the practice sessions, than more riders would have selected this option for the race.”