WRC

Swedish Rally: Michelin preview

Michelin out to extend its winning run in Sweden Unbeaten in the Swedish Rally since 1998, Michelin will be looking to continue that run over the Varmland's snowy lanes next weekend. It won't be easy but Michelin, reigning World Champions and ...

Michelin out to extend its winning run in Sweden

Unbeaten in the Swedish Rally since 1998, Michelin will be looking to continue that run over the Varmland's snowy lanes next weekend. It won't be easy but Michelin, reigning World Champions and winner of the recent Monte Carlo Rally with Sebastien Loeb and Citroën, will be able to count on its three partner-teams, Citroën, Ford and Skoda, on a strong line-up of Scandinavian drivers - Toni Gardemeister and Henning Solberg (Ford-Michelin), Janne Tuohino, Jani Paasonen and Mattias Ekstrom (all Skoda-Michelin) - as well as on France's Sebastien Loeb who last year became the first non-Nordic to triumph in Sweden.

Although competitors in the WRC were spared snow during January's Monte Carlo Rally (the day after the finish, snow fell in abundance over the southern French Alps!), they are unlikely to escape it during next weekend's Swedish Rally, the FIA World Rally C hampionship's only winter fixture.

The Swedish Rally is a particularly important round for Michelin, if only because of the technical challenge it represents. On surfaces offering essentially zero grip, the challenge is to give the drivers the best road-holding possible as well as optimal t raction over the full distance of the different groups of stages contested with the same tyres (i.e. close to 60 km). In 2004, Sebastien Loeb's winning Citroën Xsara WRC-Michelin covered the Varmland's icy and snowy stages at an average speed of 115 kph!

This technical exploit is made possible thanks to the Michelin X-Ice Sport studded tyre which has been developed especially for this event. "In Sweden, the tyre is basically there to serve the studs," says Aime Chatard, Manager of Michelin Competition's Ra llies Programme. Each Swedish Rally tyre effectively bristles with 384 tungsten studs which are glued into the tread blocks one by one and the secret of success lays in the quality of this bond between the rubber and the studs. To do this job, Michelin cal ls on the experience and expertise of the Swedish company Dackproffsen. Since 1979, Michelin has won the Swedish Rally twenty times, including an unbroken run of seven consecutive wins which began in 1998.

The Swedish Rally is also an excellent means for Michelin to enhance its notoriety on the Swedish market and, indeed, across, the whole Nordic region. Michelin has been present in Sweden since the 1920s and the country today serves as the firm's nerve cent re for Northern Europe. Elected 'French company of the year' in 2004 by the French Chamber of Commerce in Sweden for its high performance and respect for the environment, Michelin Nordic AB - the name of the Group's Swedish subsidiary which is based near S tockholm and which employs a staff of 220 - is the car tyre market leader in Sweden and across the North European zone.

This year, Michelin Nordic AB is an official partner of the Swedish Rally and the second round of the 2005 World Rally Championship coincides with the launch of a new product on the Nordic market, the Michelin X-Ice North, a studded variant of the X-Ice ra nge launched in February in the Nordic nations, Japan and Canada. "In Northern Europe, the winter tyre market is very competitive," explains Stephane Roy, Sales Director of Michelin Nordic AB. "Michelin's numerous successes in the Swedish Rally are a way o f showcasing the performance and durability of our winter tyres." To emphasise this relationship between tyres for competition use and for road use, the products with which the drivers will compete in the Varmland this weekend have been re-named 'Michelin X-Ice Sport'. "For Michelin, this two-way relationship with the road tyre is omnipresent and is one of the reasons for our presence in motor sport," concludes Michelin Competition's Deputy Director Frederic Henry-Biabaud.

PRECISION WORK

The production of the studs and the studding of Michelin's Swedish Rally tyres is a precision job that the Clermont-Ferrand company has always put out to the Swedish firm Dackproffsen. After manually drilling the tread blocks, the studs are glued in place by hand, one by one. These two operations take more than 20 minutes per tyre. That's 20 minutes of consistency and precision to drill 384 holes and glue in as many studs. For the 2005 Swedish Rally, Michelin will have close to 1,000 tyres available, a sto ck which represents some forty days of work! Despite the development of automated studding, Michelin prefers to continue with this traditional method. Tyres are living products that must be treated with the utmost care and respect! This is something that D ackproffsen has fully understood and Michelin's twenty Swedish Rally wins to date are in part down to the Vaxjo-based specialist. ON THE TECHNICAL FRONT

STUD FACTS

The studs employed for the Swedish Rally must comply with strict technical regulations:
Maximum length: 20 mm
Maximum diameter (base / mid-section / tip): 9 mm / 6.8 mm / 2.5 mm
Maximum weight: 4 g
Studs per sq. cm of tread: 20 (384 studs per tyre)

Working within these regulations, the mission of Michelin's engineers is to ensure that as many studs as possible are in contact at any given moment. "For example, if fifteen studs are in contact with the ice at the same time, our work is to see if we cann ot add a sixteenth stud with a view to optimising the constraints on each one," says Aime Chatard, Michelin's Rallies Programme Manager.

DURABILITY

"Today's trend towards covering greater distances with the same tyres - close to 60 km in Sweden this year; that's enormous! - makes it practically impossible to cover similar distances in private testing," explains Aime Chatard. "The demands made of the s tuds over so many kilometres can lead them to wear 100% which can consequently result in a performance drop of as much as 1 s/km! The driver therefore has a decisive role to play when it comes to managing his studs when an entire group of stages is made up of frozen, stony ground."

1,400 KG AND 300 BHP ON-- 2.25 SQ. CM! During the Swedish Rally, cars leave service with 1,536 studs (384 x 4), between 40 and 50 of which are in contact with the ground at any one time. The total surface of tungsten tips actually in contact with the stage would fit in a square of 15 mm x 15 mm !

A CHOICE OF 3 STUDS

Michelin runners will be able to choose from three types of stud. According to the prevailing weather conditions (very cold ice at -20C, ice at -5C and frozen, stony gravel at - 3C), the length of the visible part of the stud can vary from 3 mm (for ver y hard ground) to 8 mm (fresh snow). Despite popular belief, frozen, stony ground at -3C makes huge demands on the studs (heat build-up, risk of damage).

NEW REGULATIONS

The 2005 WRC regulations not only place a maximum limit on tyre numbers but also on the numbers of patterns that may be used. For the 2005 Swedish Rally, the drivers will be able to use a maximum of 45 tyres from a total package of 75. They have also had t o nominate a single tyre type for the entire event and the asymmetrical Michelin GE has been chosen. "In fact this simplifies our job. There was previously some hesitation between using the Michelin GA snow pattern and the GE ice pattern but, in reality, e xcept in exceptional circumstances, we tended to choose the Michelin GE more often than not," says the reigning World Champion, Sebastien Loeb.

-michelin-

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About this article
Series WRC
Drivers Mattias Ekström , Sébastien Loeb , Jani Paasonen , Toni Gardemeister , Henning Solberg , Janne Tuohino
Teams Citroën World Rally Team