August 7, 2002. Copyright, 2002, Graphic News. All rights reserved

Getting a grip: the battle for F1 tyre supremacy
By Elisabeth Ribbans

LONDON, August 7, Graphic News:  So much attention is paid to the Formula One driver, the aerodynamics of his car and the performance of the engine, that itÕs easy for the viewing public to forget the importance of the four hoops of rubber that sit at 
each corner. Yet tyres can have a bigger impact on speed than any other single element in a Grand Prix race.

Juan Pablo Montoya claimed he lost four seconds a lap to Michael Schumacher at this seasonÕs Silverstone because his Michelin ÒwetsÓ werenÕt up to the job. And while the French tyre company defended their product, blaming any apparent deficit on the 
ÒFerrari phenomenonÓ, the scoreboard did suggest rubber might be a factor: only one of the first six cars (MontoyaÕs) was shod by Michelin.

Whatever the truth, the return of Michelin to Formula One in 2001 has given rival manufacturers Bridgestone -- sole suppliers for two seasons -- some healthy competition. The Japanese firm may have stymied MichelinÕs attempt to introduce tyres sporting asymmetrical grooves at the start of the 2002 season, complaining it was an over-liberal interpretation of FIA rules, but this out-of-the-box thinking must have got the engineers back in Tokyo thinking.

Michelin (suppliers of McLaren, Williams, Renault, Jaguar, Minardi and Toyota) and Bridgestone (Ferrari, Sauber, Arrows, Jordan and BAR) each have four types of tyre: two for the wet, one for the dry, and another ÒintermediateÓ variety. The difference is forged in tread design (though, for now, all grooves remain parallel), in construction and in the compounds (or ingredients) used.

According to sporting regulations, wet tyres must have the maximum Òcontact patchÓ -- the area of the tyre that touches the road. Unlike dry tyres, the tread on wets covers the full width of the tyre and is designed to clear water from the road to prevent aquaplaning. Meanwhile, the mixture of the rubber -- a recipe kept secret by the tyre companies -- is balanced to take account of lower temperatures. A different construction may also 
allow the tread blocks to move around more to generate heat in the rubber. This is one reason why wets perform well only in a small, weather-dependant window: when the track dries out, they overheat.

Between the brands there are also key differences. Bridgestone, with a more flexible internal structure, have a reputation for good cornering, while Michelin, typically combining hard construction with a softer rubber compound, are said to produce tyres for speed. These stereotypes lost their grip this year, however, when David Coulthard rolled to victory on Michelins at the racing calendarÕs twistiest circuit, Monaco.

There is also a difference in the way the tyres are played. While Bridgestone has concentrated on producing rubber that performs well from grid to finish line, Michelin, whose tyres take longer to reach their optimum performance, often start cars with slightly pre-worn or scrubbed tyres.

As the rivalry between Michelin and Bridgestone continues, the Michelin men may take some comfort from steering scrutiny of their record beyond the bald facts. By the time Schumacher captured the championship in France, Michelin had wheeled in just two winners in 2002, compared to nine victories for Bridgestone or, to be precise, Ferraris run on Bridgestones. But beyond the Ferrari phenomenon the results table shows better balance: while Bridgestone stay ahead on 165, Michelin lag only 18 points behind.
/ENDS

Sources: Bridgestone, Michelin, Panasonic