Putting BFGoodrich's road tyres to the test
Both factory teams and private outfits are in partnership with BFGoodrich on the 2008 Dakar Rally. The factory squads have bespoke competition tyres available to them. By contrast, the amateur crews will drive the entire route
on standard BFGoodrich road tyres : the « Mud Terrain » or the « All Terrain ».
The objectives of the works teams and the privateers are very different. For the manufacturer squads, victory is the ultimate goal. For the amateur drivers, it's a triumph just to get to the finish. Fréderic Henry-Biabaud, BFGoodrich's competitions director, adds : « The Dakar Rally is an event that BFGoodrich owes it to itself to win. The rally is a unique and legendary competition that allows us to demonstrate the intrinsic qualities of the tyres we sell to our customers. These tyres are subjected to the worst possible punishment, so competition is the most effective research tool we have to develop new products for our clients all over the world. »
The BFGoodrich Rock T/A : a tyre taken to hell and back
« In order to develop an effective rally raid tyre you have to concentrate on strength above everything else, as on the Dakar Rally it's the actual carcass of the tyre that is subjected to the greatest stress, » says Dominique Bravy. « This is down to the constant pounding from the road conditions and the weight of the cars, which can reach 2.5 tonnes fully laden. A rally raid tyre can actually cope with forces of up to three tonnes, on landing after a jump for example.
It's more or less unheard of to have a day with exactly the same stage conditions for 300 or 400 kilometres. On rocky surfaces, the tyre has to be very resilient. Materials need to be used in the construction that ensure it does not deform even when subjected to a constant beating, and so minimise the risk of punctures. Sand dunes pres- ent another set of challenges, as the wheels have to avoid sinking into the soft surfaces as much as possible. Endurance is a key element that has to constantly be borne in mind.
In order to be as competitive as possible, the major parameter that we can alter is the tyre pressure. »
Tyre pressures : not just a load of hot air
With just one type of tyre allowed for the priority drivers, the trick is learning how to adapt the tyre pressures to best suit the terrain encountered. The rocky roads of Morocco require high tyre pressures in the region of 3 bars, for example, in order to protect the tyre from rocks. In the sand dunes of Mauritania, by contrast, the drivers have to drop the tyre pressures to around 1.4 or 1.5 bars, in order to maximise the amount of rubber in contact with the ground. If a car gets stuck in the sand, the tyre pressure can be reduced further to just one bar in order to help it get out.
A cockpit-controlled system of inflation and deflation is against the rules for 4x4 vehicles, so adjusting the pressures takes some time. The crews also have to ensure that they properly re-inflate their tyres after crossing any obstacles, as under-inflated tyres can increase the risk of a puncture.
Press Release BFGoodrich