For its fourth year on the MotoGP Championship schedule, Indianapolis Motor Speedway (IMS) received a facelift, the track repaved from turn 5 to the final 16th corner.
Although this helped rid of the bumpy surfaces, it also presented the 17-rider MotoGP grid with many challenges, for both riders and tires.As the grid moved from practice to Sunday’s race, the surface became very slippery, making focus on setup a bit more challenging than other tracks.And the rider who called the track his “least favorite” was absolutely unstoppable at the Red Bull Indy GP – Repsol Honda’s Casey Stoner. The Australian took the win, joined on the podium by teammate Dani Pedrosa and Yamaha Factory Racing’s Ben Spies.Following is a Bridgestone Tire Debrief with Hirohide Hamashima (Assistant to Director, Motorsport Tyre Development Division).Q.
What can you say about the new IMS surface and what did it mean for MotoGP tire performance?HH:
“The new surface started off slippery on Friday morning and because of this we experienced quite a bit of tire graining during the first free practice, particularly of the rear tires. The more laps were run on the circuit however, across all classes, the more conditions improved.“The line became clearer and more grippy as more rubber was laid down on the racing line and this changed the challenge for the tires and also the focus of bike setup. As the general grip level improved, rear tire graining was reduced a great deal but as rear grip improved, many riders experienced the front tire pushing and so front tire graining and wear rate were higher, and this point in particular proved decisive in the outcome of the race. In fact, I can say that overall durability was good as many riders set their fastest laps towards the end of the MotoGP race, including Casey’s lap record on lap 20 and Andrea whose personal best came on the very last lap.“The conditions over the weekend demonstrated very clearly the importance of a good rider and machine package in maximizing tire performance. Apart from Nicky, every rider used exactly the same tire specifications in the race yet there were those such as Casey, Dani and Ben who were able to lap much more consistently than others and had a much better wear rate of their tires.“By the end of the race we could see just by the wear appearance of the tires that the grip and character of new tarmac was much better, but I don’t think it has reached its full potential yet. The wear appearance of the tires, particularly from those at the front of the field, was the best it had been all weekend after the race so I think, bearing in mind how new the tarmac is and how little it had been used before this GP, IMS have done a good job in their resurfacing work.”Q.
What can you say about the tire compounds Bridgestone selected for the MotoGP?HH:
“I am satisfied we chose the best-suited tire compounds, front and rear, for this Grand Prix. In general, front tire performance was good all weekend and we had no tyre problems. As the track condition and bike setups changed, different demands were placed on the fronts and in some instances this led to graining, but this is a symptom of the new track surface rather than a tire issue and selecting different compounds would have made no positive difference. We will carefully analyze race tire performance but based on the new surface we may revise the tire severity rating for next year, although by then the character may have changed again so we will need to carefully consider this.“For rear tires, there were some rider comments on Friday, when the track was in its worst condition of the weekend that the extra hard compound rear was too hard to be used, but the balance at Indianapolis is one of tire temperature. Even though the circuit was slippery, rear tire temperature was very high, particularly in the left shoulders, and by the end of the race some riders experienced small blisters, which is incredibly rare. Had we chosen a softer rear compound, initial grip would have been improved but durability would have suffered meaning it wouldn’t have been a suitable option for the race.”Bridgestone MotoGP slick compounds available: Front: Soft, Medium, Hard. Rear (asymmetric): Hard, Extra Hard