May 22, 2014
French MotoGP debrief with Shinji Aoki
Bridgestone engineers work with all the teams to improve safety and performance of their Bridgestone BATTLAX tires.
Repsol Honda’s Marc Marquez continued his dominant form in this year’s MotoGP World Championship by maintaining his perfect win record for 2014 with victory at the French Grand Prix ahead of Movistar Yamaha MotoGP’s Valentino Rossi in second place, and GO&FUN Honda Gresini’s Alvaro Bautista in third.
Le Mans is fabled for its variable weather conditions, but this year conditions were fine and dry for the entire race weekend, resulting in new Circuit Best Lap, Circuit Record Lap and Average race speed records being set. Conditions at Le Mans were not only dry, but unusually warm with a peak track temperature of 46°C being recorded during Sunday’s twenty-eight lap race.
Q&A with Shinji Aoki – Manager, Bridgestone Motorsport tire Development Department
Unusually for Le Mans, this year we had warm and dry weather for every single MotoGP session. What effect did this have on tire performance?
“Overall, having the same weather for the whole race weekend had a positive effect on tire performance. It gave the teams and riders plenty of time to find a setup to extract the maximum performance out of the tires, which hasn’t always been the case at Le Mans in recent years due to variable weather conditions. Le Mans is a circuit that requires a good setup, as it is easy to get excessive wheel-spin in the many hard acceleration zones which hurts both lap times and tire durability. Our 2014 specification slick tires have been optimized for better safety, but looking at the results so far this year, we can see there is also a marked improvement in performance. This year’s French Grand Prix was no exception, with the fine weather conditions enabling Marquez to set a new outright lap record and race lap record, while the race average speed was also the fastest ever recorded at Le Mans.”
Although temperatures were quite warm at Le Mans, the hardest of the front and rear slick options were not selected by riders for the race. Why weren’t the harder slick options more widely used?
“Le Mans is not very demanding on tires, so even though temperatures were high, most riders wanted to see if they could make their softer rear slick perform consistently over the race. Looking at how quick the pace was at Le Mans this year, it seems that the riders could achieve this, so selecting the softer rear slick options for the race was logical. Those riders that did evaluate the harder rear slick options in free practice felt they got better initial performance from the softer option rear, and that they could manage the degradation in grip comfortably over longer distances.
“For the front slick, the riders now have three compound options to choose from and almost every rider felt that the soft compound front slick had the right balance of cornering and braking stability, and could still perform in its optimum range in the high track temperatures we had this weekend. However, as we visit circuits that are more severe on tires such as the Circuit de Catalunya, I think we will once again see more variety in tire choice for the race, particularly for the rear.”
Some riders are saying that the current warm-up performance of the tires allows them to reach full potential after just a few corners, whereas years ago it took at least a lap for the tires to reach optimum temperature. How was this achieved and did Bridgestone have to compromise other areas of tire performance to achieve this?
“When designing a tire, it is often a case of finding the best compromise between grip and durability as if you increase one of these, invariably you have to reduce the other. Basically, if you want a grippier tire, then that tire will need to wear out quicker. We also need to consider finding the best balance between outright grip and good warm-up performance and this is the area that we’ve worked hardest in recent years. This is why the riders now feel they can push on our tires straight away. It means that MotoGP tires are now safer than ever.
“The balance between grip, durability and operating temperature range in our MotoGP tires is now at a very good level, but this isn’t the result of one particular technology breakthrough. Rather, it is the result of the constant refinement of all aspects of the tire including compound, construction and profile development.”