Eli5 – F1 cars have smooth tyres for grip yet on a normal car this would be certain death. Why do smooth tyres give F1 cars more grip yet normal cars less grip?

Question

Eli5 – F1 cars have smooth tyres for grip yet on a normal car this would be certain death. Why do smooth tyres give F1 cars more grip yet normal cars less grip?

In: 3088

Answer 1

Smooth (or to use the automotive term, slick) tyres give huge amounts of grip, but only under a set of very specific conditions.

In particular they only work in dry conditions, and with a good quality, clean track to drive on, and soft, sticky rubber compounds – this allows all of that rubber to be in good contact with the ground, and the more rubber in contact, the more grip you have.

The problem is that if those condition change, a slick tyre will very suddenly lose traction and become dangerous. If it starts to rain for example, all it takes is a thin film of water to act as a barrier between the tyre and the road, and grip vanishes. Similarly if the road is rough or covered in debris like mud and gravel, that also creates a barrier between the tyre and the road.

The solution to this is a treaded tyre. These are tyres that have patterns of grooves cut into the surface of the tyre.
Under ideal conditions, the grooves mean slightly less rubber will be in contact with the road, so they will have less grip than a slick tyre. But as soon as conditions are less than perfect and you encounter a wet, muddy or rough road, the grooves act as channels to allow the tyre to clear water and debris out of the way and keep the rubber in contact with the ground.

The end result is that when you have a controlled situation – a clean track, and the ability to swap tyres halfway through a race if it starts to rain and you need treaded wet weather tyres, or when your soft rubber starts to wear out, then slick racing tyres will give the best performance.
If you are driving out on the public road however, you don’t have the chance to swap tyres halfway through a journey if it rains, the roads are unpredictably uneven and dirty, and you want a harder (less grippy) tyre that lasts for thousands of kilometers, not just hundreds, then you make the compromise of using a typical all weather, treaded tyre.

In fact, using slick tyres in poor weather is so dangerous, a lot of countries ban their use on public roads, and require suitably general use tyres be used.