Michelin Find Cause of Tyre Failures

A small step on the inside of the entry of the Bus Stop chicane was to blame for the tyre failures Michelin suffered during the Belgian Grand Prix last Sunday, according to Pascal Vasselon, the company's Formula One project manager.

The right rear Michelin tyre on Jenson Button's BAR-Honda car disintegrated as he travelled at 320 km/h into the Les Combes corner and he was pitched into a spin that forced him into the Minardi of Hungarian Zsolt Baumgartner.

Button's tyre failure followed a blow out for McLaren's David Coulthard early in the race, with Williams driver Juan Pablo Montoya also suffering the same problem late in the event.

The French tyre supplier launched an investigation and concluded the tyres had been damaged at the entry of the Bus Stop chicane.

"We had a late night on Sunday trying to understand what happened," Vasselon told Italy's Gazzetta dello Sport. "Dealing with damaged tyres unfortunately prevents us from establishing with certainty the nature of the failure.

"We noticed the existence of a small step between the inside of the kerb and the grass at the entry of the Bus Stop; the edge of the step is blackened, showing the frequent passage of tyres."

Toyota's third driver Ryan Briscoe also had on accident on Friday at the Eau Rouge corner due to a deflated tyre. Vasselon said they had discovered a similar problem at the exit of the chicane, too.

"We noticed that Briscoe pinched the kerb at the turn's exit and we noticed that small step when we went there for checks," he added. "The organisers sorted it out before qualifying but we did not think that the same problem was also at the chicane's entry."