Groupe Michelin has completed its investigations concerning the tires it used at the 2005 United States Grand Prix in Indianapolis (see "Controversy over Michelin tires taints Grand Prix race in Indianapolis," June 20, 2005, Web item).
"The tyres were not intrinsically flawed, but were insufficiently suited to the extreme racing conditions encountered through Turn 13 of the Indianapolis circuit this year," the company told its seven partner teams, which have been "summoned" to a June 29 hearing by the Federation Internationale de L'Automobile (FIA) for refusing to participate in the race.
In an official statement, Michelin had this to say following its investigation.
"Given the evolutions concerning the cars' aerodynamics, the regulations which govern the sport and the nature of the track surfaces, etc., Michelin carries out testing in the course of each season with a view to developing the tyres which are the most suited to each event. Two key elements must be known about the Indianapolis circuit:
* Turn 13, with its severe banking, is the only turn of its kind in a season of 19 races.
* Testing at Indianapolis was not possible.
"As a consequence, in order to define the specification of its tyres for Indianapolis, Michelin had to carry out simulation work based on the results of less severe testing at other venues and on estimations concerning the specific conditions likely to be met at Indianapolis in 2005. The Michelin investigations have revealed that the loads exerted on the rear left tyre through Turn 13 at Indianapolis were far superior to the highest estimations of 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. The tyres which Michelin took were therefore insufficiently adapted to the extreme conditions of Turn 13 in 2005. This was a problem.
"On the other hand, investigations concerning the materials and construction employed for the tyres produced for Indianapolis have confirmed the absence of any anomaly. The tyres did not have an intrinsic flaw but they were not insufficiently suited to turn 13. Moreover, this analysis confirmed the pertinence of the tyre solutions specified for all the other circuits.
"In retrospect, this analysis perfectly validates the pertinence of the precautionary measures requested by Michelin and its partner teams in the interests of driver safety and fully confirms that the addition of a chicane at the entrance of Turn 13, which would have guaranteed lower speeds through Turn 13, would have enabled spectators not to be deprived of a high class competition, while at the same time guaranteeing the safety of the drivers."
As a consequence of the results of the investigation, Michelin has
1. revised its simulation model for "banked" corners such as Turn 13 at Indianapolis in view of the special effects caused by this corner.
2. requested that it be possible in the future to undertake testing at Indianapolis before the Grand Prix.
3. confirmed that it will be present with safe, competitive tyres at the forthcoming Grand Prix races.
In conclusion, according to Michelin Motorsport Director Pierre Dupasquier, "The problem was that we under-evaluated the extreme constraints to which tyres were exposed through Turn 13 in the specific context of 2005. We are grateful to our partners for their work with us right up to the last moment to seek a solution that would have permitted the race to go ahead in total safety.
"We regret that the spectators did not see an exciting race. However, in keeping with its principles, Michelin did not sacrifice safety for performance."
