Indianapolis MotoGP 2015 DebriefRepsol Honda’s Marc Marquez remains the King of America in MotoGP after claiming yet another victory Sunday on US soil during the Red Bull Indianapolis Grand Prix, round 10 of 18.The 22-year-old Spaniard has now won every American round he has ever competed in, from Indy to Circuit of the Americas to Laguna Seca Mazda Raceway.
Marquez earned the pole for Indianapolis MotoGP 2015, and followed that up with the win aboard the Repsol Honda RC213V. But it wasn’t easy for the two-time reigning MotoGP Champion; he dueled with Movistar Yamaha’s Jorge Lorenzo for the opening 25 laps before taking the lead.Marquez would not be challenged again, and earn his third-straight win at Indianapolis Motor Speedway. Marquez was joined on the Indianapolis MotoGP 2015 podium by two Yamaha YZR-M1 pilots – Lorenzo and the current points leader who has yet to finish off the podium, Movistar Yamaha’s Valentino Rossi.En route to the win, Marquez set a new Circuit Record of 1:32.626 around the 2.591-mile circuit containing 16 corners. He also set a new overall race-time record of 41:55.371 – beating the previous record set by Marquez last season by 12 seconds.Much of the record success was attributed to Bridgestone tire performance and lack of rain that threatened the track Sunday. For more analysis of Indianapolis MotoGP 2015, here’s a Q&A with Masao Azuma – Chief Engineer, Bridgestone Motorcycle Tire Development Department.Q. The Indianapolis Motor Speedway is a very demanding circuit for tires, particularly for the rear. Given the severity of the circuit and the big difference in weather conditions between the practice sessions and the race, what’s your assessment of tire performance at this year’s Indy Grand Prix?Masao Azuma says: “Indianapolis is a very demanding circuit and as well as being severe on tires, the grip level can vary quite a lot over the weekend. This year however, although the grip of the tarmac was low during the first sessions, overall the conditions were quite good for this circuit, even with track temperatures reaching well into the fifty degree Celsius range.“If you look at the track temperatures on Friday afternoon compared to the race, the difference is almost twenty degrees Celsius yet tire performance remained very good in these highly variable conditions, so I am quite pleased with this. During the race we had some light drizzle but even so, there was a new Circuit Best Lap and overall race time record set and the riders were able to push at 100 percent throughout the race. This is a good outcome for us and shows that our tire allocation for this year’s Indianapolis Grand Prix was well suited to this circuit.”Q. Bridgestone has been quite active in tire development this year, so where there any significant changes in the tire allocation for this year’s Indianapolis Grand Prix?Masao Azuma says: “We didn’t have to change too much this year as last year’s Indianapolis tire allocation performed quite well. However, given the increased performance of the open class machines this year, we revised our allocation so that the soft option rear slick was closer to the medium rear in its composition.“This change worked well as many open class riders were able to use the soft compound rear slick for the race with good results. For the front tire, the availability of the new hard compound front slick at Indianapolis was a good addition to our tire allocation and was well received by the riders. So there were minor changes made compared to last year’s Indianapolis Grand Prix, but the changes made had positive results.”Q. Last year at Indy just two riders selected the hard compound front slick for the race, with most preferring the medium front. This year however, 21 riders selected the hard compound front. Why was there such a huge shift in front tire preference from the medium to the hard compound front slick in 2015?Masao Azuma says: “The hard compound front slick that we brought to Indianapolis this year was the first time this specification of tire has been available at this circuit. Last year the riders selected the medium compound front slick as although it lacked the braking stability of our previous hard compound front slick, its cornering performance and feedback was quite a bit better than the hard front.“However, our new hard compound front slick offers the same excellent braking stability as before, but with better edge grip and feel than and this combination made it extremely popular this year. Therefore, the shift in preference from the medium to the hard front slick at Indianapolis this year was due to the improved grip and feel of our latest specification hard compound front slick.”For more, visit our results and recap of Indianapolis MotoGP 2015.