Sweden 2006 Rally: BFGoodrich - Preview
After the sand of the Dakar Rally and the icy asphalt of the Monte Carlo, the focus for BFGoodrich now switches to the ice and snow of Sweden. On a surface on which it is barely possible for a person to remain standing for very long,
just how do rallying's stars succeed in getting up to speeds of more than 200kph at the wheel of World Rally Cars that sit on just a handful of tiny studs?
More than just another challenge, it's a fight against nature that BFGoodrich tyres face in the Scandinavian event! Take Control...
As the sole winter fixture of the WRC calendar, the Swedish Rally calls for long, painstaking preparation work and, each year, the possibility that teams won't find the same conditions in the Värmland in early February as they encountered during testing in December is very real.
Competitors can effectively come across nearly just as many different types of ice during the Swedish Rally as the number of flavours they can find at a Haagen-Dazs store! Quipping aside, the tyre/stud packages drivers use need to be perfectly suited to 'very cold' ice (between -20 and -10°C), to 'normal' ice (between -5° and -2°C) and to 'slushy' ice (between 0° and +2°C), the latter being the type crews found last year.
"A simple ice cube illustrates the different types of ice you can find in Sweden," explains BFGoodrich's Rallies Programme Manager Aimé Chatard. "A 'very cold' ice cube straight out of the freezer tends to stick to your fingers. After a moment, when it begins to melt, it begins to get very difficult to keep it in your hand because it's so slippery."
The quality of the bond between the rubber of the tread blocks and the metallic studs is another key parameter. Every BFGoodrich g-Force Ice features 384 studs which are glued into place one by one, an operation that requires one hour per tyre.
The FIA has specified a maximum length for studs (2cm) which means that the amount of metal fixed in the tread block in fact varies according to the terrain. If the stages are covered in a deep coating of snow, it is necessary to leave as much of the stud protruding from the tyre as possible in order for it bite through the snow. At the same time, however, it is important that this doesn't detract from the quality of the bond between the concealed part of the stud and the tread block. In case of protruding stones, it works the other way round.
"Last year, temperatures were exceptionally mild," recalls Aimé Chatard. "The melting ice saw stones to come to the surface and this was very punishing for the studs. We have tried to remedy this problem this year, but will the conditions be identical?" Marcus Gronholm
"This is my favourite rally and it brought me my first WRC win. We worked very hard in winter testing and I tried all the latest evolutions proposed by BFGoodrich. They are competitive and last well. I am very confident. I don't believe the return of non-active differentials will have a major influence in Sweden because the stages tend to be very fast and grip is consistent."
Press Release BFGoodrich