richard_leeds wrote:As for asphalt, when it is first laid it has a smooth surface formed by the rollers. As the traffic runs over the new surface it wears away the soft binder (bitumen) and filler (fine aggregates). The result is that the hard coarse aggregate (ie stones) are left standing proud. That's the optimum texture for tyre friction.
Then as further traffic passes over the surface it wears down the aggregate, and the sharp arises (corners) of the aggregate are worn to rounded edges. Hence the overall "friction" goes down.
Depending on traffic and climatic conditions, the optimum roughness is roughly 1 year, then the roughness trails off over 10- 20 years.
That is a good summary of the general mechanism. It complements nicely the source that Ciro contributed. I would assume that racing tracks get much less wear than busy public roads or highways and their wear should generally occur over longer periods of time. I was reporting on the tyre grip issues because it was mentioned by former F1 driver Marc Surer who talks to the drivers quite a lot and has very good technical understanding. I was a bit shocked to be honest that some make it a personal issue to prove Surer wrong. It is not such an important issue that we bicker over it. So I will not continue the discussion.
Latest odds on pole:
Lewis Hamilton 2.25
Sebastian Vettel 3.75
Fernando Alonso 15
I'm not so sure that Alonso is so far behind. It is nice to see Red Bull in good shape for the race. I think they have done a lot of work on the race set up in FP 1/2.