WRC

Rally Finland Michelin preview

No let-up possible! Between now and the end of the year, with the three most punishing rounds of the year (Cyprus, Greece and Kenya) effectively behind them, the stars of the 2001 World Rally Championship will be able to let their talent ...

No let-up possible!

Between now and the end of the year, with the three most punishing rounds of the year (Cyprus, Greece and Kenya) effectively behind them, the stars of the 2001 World Rally Championship will be able to let their talent talk. Without reservation. Whether it be over Finland's fast and furious roller-coaster, over New Zealand's beckoning sinuous lanes, on the twisty tarmac of Sanremo or Corsica, over West Australia's celebrated "marbles" or in the equally famous forests of South Wales, the scene is set for yet another fascinating scrap as the season's title chase enters its final phase.

While Mitsubishi-Michelin and Tommi Makinen currently figure at the top of their respective points tables, the way the year has unfolded so far has produced a remarkably open situation in which all the sport's top names still stand a chance of clinching the 2001 world crown. On the tyre front, the hard work put in by Michelin's technical staff in preparation for the recent Safari Rally was rewarded when Makinen took an emphatic victory to head an all-Michelin podium that featured all three of the firm's partners present in the African classic (in order: Mitsubishi, Peugeot and Skoda). It was a result that can only strengthen the French manufacturer's resolve to secure a third consecutive Drivers/Manufacturers double at the end of the year.

With six rounds remaining, Michelin has every reason therefore to keep up the same high level of effort that has seen it win five rounds from eight to date. Each of the rallies to come represents a unique and demanding challenge, beginning with Finland, the fastest round of the year. Twelve months ago, Marcus Gronholm won his home event for Peugeot-Michelin at an average speed of 120 kph! When the going gets that quick, tyres need to combine swift, accurate steering response with high performance... in all three planes. For the stages around Jyvaskyla abound in the vertiginous jumps that have long been the hallmark of this exceptional show!

Tyres and the World Rally Championship Like any tyre (car, truck,...), a World Rally Championship tyre has to fulfil a certain number of functions: grip, absorb, steer, transmit, resist. To be competitive, it must of course combine all these roles. However, the specificity of each round tends to put the spotlight on one or sometimes two of these functions...

GRIP
Grip is generated by the reaction of the rubber's molecules over the unevenness of the ground. The tyre's pattern and dimensions contribute to grip by optimising the contact between the tread and the road.

ABSORB
The properties of tyres and the air they contain form an integral part of the vehicle's suspension, especially since the tyre is in the front line when it comes to soaking up obstacles on the road.

Tyres must be capable of responding instantly and as accurately as possible to drivers' instructions via the steering wheel. Construction and compound directly influence the quality of this response. (e.g. brushing aside the loose top layer of gravel),

TRANSMIT
Not only must the tyre transmit the vehicle's power to the ground, but its construction and pattern must also enable it cope efficiently with the effects of torque, be this positive (acceleration) or negative (braking). must not be to the detriment of the tyre's other

RESIST Despite suffering repeated aggression due to the extreme running conditions (long distances at high speed, high temperatures, long groups of stages, rough ground), the tyre must conserve its performance characteristics over time.

STEER Any car travelling on a surface that is not perfectly flat requires permanent corrections via the steering wheel to keep it in line, not to mention the instructions a driver gives when he wants to corner. In cases where high performance steering is crucial, the more drivers call for swift, accurate response each time they turn the wheel... in addi- tion of course to first class traction and lateral grip.

Tyres are a fundamental link in the steering chain and the quality of their response is especially critical when flashing past the solid trees of Rally Finland's bobsleigh run at over 180 kph!

On the narrow gravel lanes of the WRC's fastest round*, where the constant movements of the steering wheel coupled with the driver's playing on the throttle create a complex situation for tyres, drivers demand the same steering precision as they would on tarmac. Except that on gravel, the tyres come with a pattern made up of hundreds of deformable rubber blocks.

Designed to carry out a number of key functions (e.g. brushing aside the loose top layer of gravel), these blocks can be made more or less flexible according to the needs of each rally and/or surface. To optimise their response time when transmitting orders from the steering wheel to the ground (around 1/100th of a second at Finland's speeds!), they need to be as rigid as possible. Yet this rigidity must not be to the detriment of the tyre's other roles. For optimised performance, the blocks therefore have to be carefully defined to work harmoniously with both the overall rigidity of the casing itself and the tyre's grip enhancing properties. 2 Michelin's range for Finland

Clear, hard ground
Michelin Z, 17/65x15
A more open tread pattern than the Michelin ZB. The ground rigidity of the Michelin Z's tread blocks limits their mobility on aggressive stage surfaces.

Damp, soft or loose stages
Michelin ZA, 17/65x15
A relatively open tread pattern to penetrate the loose top surface in search of more compact ground deeper down.

Soft ground or loose gravel
Michelin ZE, 16/65x15
The Michelin ZE differs notably from the Michelin ZA by its more open tread pattern and its availability in a narrower dimension.

These products are available in two compounds according to conditions: 8 (for mild weather or wet ground) and 9 (for hot weather and/or harder wearing stages). Michelin has a total staff of 24 in Finland. The total number of covers available for the event is approximately 4,220 carried in 11 semi-trailer workshops. All are fitted with Michelin's ATS system (Appui Temporaire Souple). These figures do not include those teams supplied and serviced by Michelin Finland.

Michelin's WRC partners in Finland:

HYUNDAI MOTORSPORT:
Alister McRae/David Senior (GB/GB)
Kenneth Eriksson/Staffan Parmander (S/S)
Juha Kankkunen/Juha Repo (FIN/FIN)

MARLBORO MITSUBISHI RALLIART:
Tommi Makinen/Risto Mannisenmaki (FIN/FIN)
Freddy Loix/Sven Smeets (B/B)
Toni Gardemeister/Paavo Lukander (FIN/FIN)

PEUGEOT SPORT:
Didier Auriol/Denis Giraudet (F/F)
Harri Rovanpera/Risto Pietilainen (FIN/FIN)
Marcus Gronholm/Timo Rautiainen (FIN/FIN)

SKODA MOTORSPORT:
Armin Schwarz/Manfred Hiemer (D/D)
Bruno Thiry/Georges Biar (B/B)
Stig Blomqvist/Ana Goni (S/YV)

Recent Rally Finland winners:
2000 Gronholm/Rautiainen (Peugeot - Michelin)
1999 Kankkunen/Repo (Subaru - Pirelli)
1998 Makinen/Mannisenmaki (Mitsubishi - Michelin)
1997 Makinen/Harjanne (Mitsubishi - Michelin)
1996 Makinen/Harjanne (Mitsubishi - Michelin)
1995 Makinen/Harjanne (Mitsubishi - Michelin)
1994 Makinen/Harjanne (Mitsubishi - Michelin)
1993 Kankkunen/Giraudet (Toyota - Michelin)
1992 Auriol/Occelli (Lancia - Michelin)
1991 Kankkunen/Piironen (Lancia - Michelin)

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About this article
Series WRC
Drivers Tommi Makinen , Freddy Loix , Harri Rovanpera , Didier Auriol , Marcus Gronholm , Alister McRae , Armin Schwarz , Timo Rautiainen , Juha Kankkunen , Kenneth Eriksson , Risto Mannisenmaki , David Senior , Risto Pietilainen , Toni Gardemeister , Denis Giraudet , Paavo Lukander , Juha Repo , Sven Smeets , Stig Blomqvist , Staffan Parmander