After having a tire chunk...
After having a tire chunk and ruin his prospects for a podium finish at Assen, Yamaha's Ben Spies isn't angry at Bridgestone.
HOHENSTEIN, ERNSTTHAL, GERMANY, JULY 6 – What happened to the rear Bridgestone tires of Valentino Rossi and Ben Spies at last week's Dutch TT remains a mystery, despite an in-depth analysis by Bridgestone.
Shinji Aoki, Bridgestone's manager of motorsport tire development, briefed the media on the progress of the investigation following the end of day rider briefings at the German Grand Prix. Most of the riders believed Bridgestone was being sincere when they said the tires weren't defective, but Repsol Honda’s Casey Stoner wasn't as forgiving.
The entire Repsol Honda team has been critical of Bridgestone ever since they introduced a new, softer construction front tire during testing. The tire was put into service at the British Grand Prix at Silverstone, where Stoner finished third behind Yamaha’s Jorge Lorenzo and Repsol Honda’s Dani Pedrosa. Stoner won on the tire last weekend in Assen.
Asked what he’d been told about his Assen tire, which was missing two big chunks, Yamaha’s Spies said, “I was waiting for that one.
“Really, nothing useful, honestly. I mean, plain and simple.” He said the team had looked at the data on his bike and that of Monster Yamaha Tech 3’s Andrea Dovizioso and both had similar set-ups. “His percentage of spin was more than me in the race. Those are the only facts we have and why mine was the one that chunked and his not, I don’t know.”
Spies believed that Bridgestone hadn’t had enough time to properly analyze the tires, which were immediately air freighted back to Japan following Saturday's Dutch TT.
“The real answers, I mean, it’s a hard one to find out in one week for anybody and I know they’re doing their best to figure out what’s going on and to fix it for the future,” he said. “But in that short a time I don’t think they can learn 100% of what exactly happened.”
The problem was caused by overheating; that much is known. What caused the overheating remains a point of contention, Bridgestone's Aoki said. Aoki speculated it could have been a combination of factors; the increase to 1000cc from 800cc, the increased track temperature-it was 18C last year and 40 this year-and the many banked corners of the track. Those things, and the various riding styles, electronics and suspension set-ups contributed to the tire failures.
Aoki said Bridgestone had extensively tested the tires in Japan, both before and after the race, on their rolling drum, one of the largest in the world.
“So finally we said, OK, this spec, not this lot or batch, this spec not enough performance against this year’s Assen,” he said. But, he added, from the data supplied by the teams, which can measure tire temperatures throughout the race, “only a few riders saw high temperatures compared to other riders.”
Rossi had the worst tire degradation of all. His was so bad that he had to pit to change tires, after his rear had lost much of the rubber off the right shoulder.
“The tire doesn’t have any problem about, so from Bridgestone’s side,” he said. “Create a lot of too much temperature from the inside and for this reason broken the rubber. But maybe it’s something about the setting compared to the other guys. And we don’t know exactly why.”
In his meeting with the media, Stoner, who didn’t have a tire problem in Assen said, “Their tires are getting worse, the lap times year by year are getting worse.” He added, “They will never admit that anything’s wrong with their tires. This is the biggest problem.”
Told these comments, Aoki laughed and said, “I don’t think so, because as you know the lap time is not getting worse.” He added that the motorcycles were getting better and the lap times had improved. “Especially this year, every circuit is faster than last year.”
As to why Stoner would say that Bridgestone wouldn’t admit its tires were faulty, Aoki said, “I don’t know why he said something like that.” Aoki pointed out that everyone gets the same level of support, from the CRT teams to the factories. “At this moment sounds like Casey is not so happy.”