As is customary, the Bridgestone media service issued their post-race debrief on tire performance on Tuesday, in which they discuss how the tires they selected held up during the race at Le Mans the previous weekend. This week’s press release is more interesting than most, as it contains a denial from Bridgestone that there was anything wrong with the rear tire used by Jorge Lorenzo in the race on Sunday, countering claims that his tire was defective.
Speaking to the media after the race on Sunday, Lorenzo said that although he was not a tire engineer, he could think of no other explanation but a defective tire for the complete lack of rear grip he had suffered throughout the race. The setting they had used in the wet morning warm-up had worked well, Lorenzo said. In 2012, under similar conditions, he had not had a single problem, he explained, going on to win the race by nearly 10 seconds.
Lorenzo also pointed to the fact that Valentino Rossi had had problems with a tire on Saturday morning, and had that one replaced, as is allowed under the rules if a defective tire is found. Bridgestone denied on Sunday night that there was a problem with Lorenzo’s tire, and have reiterated their stance in the official press release. The tire was examined by both Bridgestone technicians and Yamaha engineers, and found to have normal wear only.
Shinji Aoki, manager of Bridgestone’s Motorsport Tire Development Department, gave Bridgestone’s official response in the press release as follows: “It was clear during the race that Jorge had an issue as he couldn’t keep the same pace as the leading group. Immediately after the race he had a debrief session with his tire engineer where he explained his lack of rear grip.”
“As is always the case in these situations, his engineer thoroughly examined Jorge’s race tires which were found to be in good working condition. In addition, I examined the tire myself and personally discussed the matter with the Yamaha engineers and we all agreed that Jorge’s lack of rear grip was not attributable to his tire.”
“We received many different comments from the riders after the race on the feeling on the track, even though they all used the same specification of wet tire and endured the same track conditions. In these low grip situations, machine set up is critical as the smallest setting change can have a big effect on performance.”
Whether Lorenzo has changed his mind or not is still unclear, though the 2012 World Champion has gone back and deleted a number of messages he posted on Twitter on Sunday night. No doubt more questions will be asked once the MotoGP paddock arrives at Mugello, in just under two weeks’ time. Below is the full text of the press release issued by Bridgestone today:
French MotoGP™ debrief with Shinji Aoki
Tuesday 21 May 2013
Bridgestone slick compounds available: Front: Extra-soft, Soft Rear: Extra-soft (Symmetric), Soft, Medium (Asymmetric)
Bridgestone wet tyre compounds available: Soft (Main), Hard (Alternative)
Repsol Honda’s Dani Pedrosa won a wet and wild French Grand Prix ahead of second-placed Cal Crutchlow on the Monster Yamaha Tech 3 M1 and teammate Marc Marquez who was third.
The riders were met with extremely challenging conditions at Le Mans for the fourth Grand Prix of the year, with wet asphalt and a track temperature of just 14°C at the beginning of the race, and a rapidly drying track surface which caused variable grip conditions towards the end of the twenty-eight lap contest.
Q&A with Shinji Aoki – Manager, Bridgestone Motorsport Tyre Development Department
Cold and wet conditions were forecast for the weekend of the French Grand Prix and this is indeed what happened, can you explain how these conditions affected tyre performance at Le Mans?
“Yes the conditions were as expected but this didn’t make it any easier for the riders! Track temperatures were very cool, as low as 13°C and although we brought our softest tyre compounds to this race, the track didn’t provide the best grip levels, particularly in the morning sessions. The consensus from rider feedback was that tyre warm-up performance over the weekend was good, but even so the cool ambient temperatures and strong breeze meant some riders got caught out during practice and qualifying. The cold conditions also meant that very few riders tried the harder rear slick options as they wanted the best rear grip and warm-up performance possible, which is especially important at Le Mans which has a stop-and-go layout with a lot of acceleration zones.
“Sunday presented a different kind of challenge for the riders as the only time during the race weekend when track conditions were fully wet was at the beginning of the MotoGP race. Although morning warm up was declared wet, it wasn’t raining, so the level of standing water on track was less than at the beginning of the race. With such limited time to find a wet setup and considering that Le Mans requires good levels of rear grip, every rider ended up choosing the softer wet tyres for the race.
No riders selected the harder compound wet tyres for the race, but would this option have worked better towards the end of the race when the track was drier?
“Some riders actually did try the front and rear hard compound wet tyres in morning warm up, and other riders also scrubbed in a set of hard wet weather tyres on the sighting lap just before the race. However, because it was so cold which made the grip level of the circuit very low, every rider decided the soft compound wet tyre was the best choice, and I think this was the right choice given the conditions. Even though the track began to dry towards the end of the race, the rate of abrasion on the soft wet tyre was still within the acceptable range, so I don’t think the harder wet tyre would have given a performance advantage at the latter stages of the race. However, if the track temperature was say, five degrees warmer then I believe we would have seen some riders select the harder wet tyre for the race and this option may have given riders a performance advantage in some areas, particularly when braking.”
Jorge Lorenzo said he had a lack of rear grip during the race; did this have anything to do with his tyre?
“It was clear during the race that Jorge had an issue as he couldn’t keep the same pace as the leading group. Immediately after the race he had a debrief session with his tyre engineer where he explained his lack of rear grip. As is always the case in these situations, his engineer thoroughly examined Jorge’s race tyres which were found to be in good working condition. In addition, I examined the tyre myself and personally discussed the matter with the Yamaha engineers and we all agreed that Jorge’s lack of rear grip was not attributable to his tyre. We received many different comments from the riders after the race on the feeling on the track, even though they all used the same specification of wet tyre and endured the same track conditions. In these low grip situations, machine set up is critical as the smallest setting change can have a big effect on performance. In any case it was a shame for Jorge as he was so strong in morning warm-up and we all expected a better result from him, but he is a champion and I know he will be back to his competitive best at the next race.”
This article was originally published on MotoMatters, and is republished here on Asphalt & Rubber with permission by the author.