A question of tyre safety

Ralf Schumacher's tyre, United States GP 2005

Ralf Schumacher's tyre, United States GP 2005 

 © The Cahier Archive

The recent days have seen the question of tyre safety bubbling away quietly beneath the surface in F1, notably between the FIA and Michelin. This was sparked by the Michelin tyre problems in Indianapolis which were followed on Tuesday by a fax from the FIA to Michelin which revealed that the federation wants details of all Michelin's tyre failures in the last two years.

"Further to the incidents at Indianapolis last weekend," Mosley wrote. "We have reason to believe that Michelin have suffered at least two major tyre failures at high speed in private testing. We have also received information which suggests that Michelin Formula 1 tyres have been prone to sidewall failure for the past two years and that some of the failures last year which were blamed on debris on the circuit may in fact have been due to tyre defects unconnected with debris.

"After the failures at Indianapolis, you informed us and the media that you were flying in "Barcelona" tyres and that these would be safe. You then withdrew these same tyres within 24 hours on the grounds that they were not safe. In your letter of June 18 you told us that despite full analysis and evaluation you did not know the "root cause" of the problem. Nevertheless despite this lack of understanding you stated that your tyres could be used if vehicle speeds in Turn 13 were reduced. However only one or your major failures was in that corner, the other was in Turn 5 in the infield. You will certainly understand that we find this lack of clarity and apparent lack of understanding deeply disquieting.

"Would you therefore please supply us, as a matter of urgency, with full details of all failures your tyres have suffered over the past two years when fitted to Formula 1 cars. Would you please also tell us precisely what you have done or are doing to prevent further tyre failures. Obviously we will treat all technical information as strictly confidential.

"As soon as we receive this information, we will submit it to independent technical experts (in confidence of course) for urgent evaluation. Based on their report our technical department will decide whether or not to invite the stewards of the French Grand Prix to exercise their powers under Article 127 of the International Sporting Code (Dangerous construction. The stewards of the meeting may exclude a vehicle whose construction is deemed to be dangerous). In respect of any car fitted with Michelin tyres."

This did not go down well at Michelin and Edouard Michelin responded with a letter which was highly critical of Mosley, which appeared in the press earlier this week.

This morning, Mosley responded to that letter.

"We cannot agree with your claim that Michelin did 'the maximum to preserve a true and safe race'," Mosley wrote. "You failed to bring a safe back-up tyre to the event and your representatives apparently refused to countenance any solution other than a chicane. Anyone with knowledge of the International Sporting Code or an appreciation of the legal climate in the United States would know that a chicane was never an option.

"You say in your letter that "investigations have revealed that the loads exerted on the rear left tyre through Turn 13 at Indianapolis were far superior to the highest estimations made by Michelin's engineers this year, the situation through this corner turned out to be altered by the extreme combination of the speed, lateral acceleration and additional dynamic load". This is a quite extraordinary statement. The banking on Turn 13 has been there for nearly 100 years and Michelin have raced on it many times. Did Michelin really not know the loads or failing that, not have the means to calculate or simulate them?

"The statement in your company's letter of January 27 to the World Council that the Formula 1 regulations do not 'require that a manufacturer supply tyres that would not undergo degradation or bursting when used in very extreme conditions' is equally extraordinary. What is Formula 1 if not motoring "in very extreme conditions".

"We look forward to receiving as promised the technical information requested in our letter of June 21 following which we will be in touch again."

All of this is profoundly worrying in that the FIA seems to be set on a path to blame everything that happened at Indianapolis on Michelin.

The company has admitted that it made a mistake and has announced that it will refund tickets for those who attended the race and will buy 20,000 tickets for fans for next year's race but does not accept that Michelin was to blame for the debacle in the race as it argues that a chicane would have been a perfectly acceptable solution to make sure that the race went ahead without the fans being left in the lurch.

Mosley has rubbished the idea of chicane on several occasions but unwittingly confirmed at his press conference that the FIA did not even check to see if its insurance would cover such a thing.

"There were two fundamental problems with the chicane, to be clear," Mosley said. "One was that the circuit would not have been properly inspected, homologated, probably the insurance would have been invalid and there may have been safety issues."

Mosley made the point that such a change would have been unfair from a sporting point of view.

"What would have happened if it had been the other way around and Ferrari or one of the other Bridgestone teams had gone to Charlie Whiting and said 'You need to install a chicane because our tyres won't work around the banking'?"

The question, however, is not really valid. As Michelin's request was not based on six cars, four of them running as also-rans, but on 14 cars, the majority of which were racing at the front. There is an important difference because the request was not based on performance but rather on producing a show. If 14 front-running cars had lined up on the grid at Indianapolis, there would have been some disappointed Ferrari fans, but there would have been a perfectly acceptable race for the fans to watch.

This is a very significant difference.

Another point which should be made is that Bridgestone may have benefited from data at Indianapolis from its sister company Firestone.

It is worth remembering that in April - before the Indianapolis 500 - the Indianapolis Motor Speedway had a test for Firestone to test its IRL tyres following the resurfacing of the track in the spring. The new surface lacked grip and this resulted in Firestone cancelling its Indy 500 tyre test after the first day when drivers reported that the track lacked grip and was too bumpy. The asphalt was then ground down to make it smoother, the delays meaning that Goodyear was asked to postpone a test which had been planned in preparation for the Brickyard 400 NASCAR race.

The grinding increases the grip and this may have been a contributory factor to Michelin's problems as the tarmac was very different in Turn 13 compared to last year.

With Michelin and Bridgestone pushing development in search of the most competitive tyres, there is always going to be an element of risk at circuits where there is no pre-race testing.

It is one of the drawbacks of allowing a tyre war.

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