Williams F1
Kerbs are important
By Allianz Article
June 5 2002



Kerbs are important
Kerbs have special importance at the Canadian Grand Prix. Together with cars' suspension, they take a lot of punishment on the fast urban circuit The Canadian Grand Prix at the Circuit Gilles Villeneuve has always managed to leave a few drivers floundering - not because the circuit on the Ile Notre Dame is surrounded by the Hudson River, but because the technical circuit cruelly shows up any shortcomings in driver skill.

Montoya using kerbs in 2001Canadian GPThe race in Montreal is held on public streets, and parts of the route are considerably faster than other city circuits. The uneven surface and poor grip at the start of the race weekend cause a lot of spins. But there are also places where drivers deliberately leave the safe concrete track - the battle for those decisive hundredths of seconds is often decided on the kerbs in Montreal. Drivers and cars that ride the kerbs well can gain a considerable time advantage on their opponents.

Both loved and feared, flattened concrete kerbstones are to be found in all the circuit's corners and chicanes. Mostly painted red and white, they are intended to prevent unauthorized short-cuts and keep the race safely on the track. But the racing line in Formula One often takes cars perilously close to the edge of the track. A good example: Coming out of the chicane before the final straight, drivers ride the kerbs particularly hard to maintain as much momentum as possible. "To get a good lap time, you have to use the kerbs," confirms BMW WilliamsF1 Team driver Ralf Schumacher.

But kerb-riding is risky. In the old days, sharp kerbstones always threatened to cut or damage car tyres. They have since been flattened, but drivers still have cause to fear them because they can damage the undercarriage of a Formula One car. The tiniest deformation is enough to destroy the car's aerodynamics - and it can become uncontrollable. In wet weather, too, the kerbs add an additional slippery element to the race track. Thus the idea of replacing kerbs with an electronic display using induction loops is under consideration. A signal light would alert the FIA (Fédération Internationale de l'Automobile) stewards when a car left the track, and time penalties could be imposed. But the system is still moot, and there are no concrete plans.

To allow cars to ride kerbs safely, racing engineers are tinkering with special suspension tunings for different types of kerbstone. For this to work, it's important that a car absorbs shocks well. Special emphasis is placed on adjusting the wheel suspension softly enough to absorb impacts and bumps. Tyre manufacturers also play a crucial role. Last season, Michelin manufactured a relatively soft tyre that handled the kerbs especially well. In the end, however, drivers decide whether kerbs are a curse or a blessing, for they're the ones who have to keep their car balanced on the edge. This takes huge skill, and those who hit kerbs too hard in Canada are lose valuable fractions of seconds.

In normal traffic, kerbs are effectively the protective wall that stands between the road and the pavement. Those who ignore high kerbstones risk tyre damage - at the very least. "Hitting kerbstones can damage tyres, with grave consequences later on," explains Dr. Hartmuth Wolff from the Allianz Center for Technology (AZT). "Drivers should therefore try to avoid hitting the kerbs. If you have to do so, make sure you're going slowly and that you hit the kerb as close to a right angle as you can. Tyres should also not be squeezed against kerbstones."

Defective tyres are one of the most common technical causes of accidents. Kerbstones represent an even greater hazard for cyclists, who run an especially high risk of falling when riding up them at a sharp angle. Careful planning of bicycle paths and indentations in kerbstones help improve safety in this area.

Keeping your distance from the car in front - and from the edge of the road - is as relevant to road cars as it is in Formula One. Kerbs play an important part in helping drivers of normal cars to be aware of their limits, just as they do in F1.

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