Here. This short article discusses the three main kinds of friction that occur in rubber tyres (adhesion, deformation and wear), which sets them apart from most other materials. Especially the following part was interesting to me: I know that rF2 takes into account how the grip varies between the racing line and the off-line when in the wet, but the reasons I've heard have been exactly along the lines of oil and wet rubber make the racing line more slippery. If this is indeed a myth, and the real reason is the that the racing line is just more worn and hence has less deformation friction to offer compared to the relatively unused off-line, it would be good to take this into account when designing the weather system or even specific tracks. Lord knows there are plenty of street circuits in the world, a good example would be Monaco. If the article is indeed right, then there shouldn't be a huge difference in grip between the racing line and the off-line in Monaco, since every day driving has probably worn the tarmac down from just about everywhere. Discuss.
Tim, myself and a few others were talking about this quite a while back and pretty much said exactly what the article you quoted said.
Wrong, tire compounds are very different in street and race tires, and one compound could not work with completly different other rubber compound.
Um: http://isiforums.net/f/showthread.php/4421-A-bit-of-an-interesting-read-regarding-tires Just two posts below yours. Re: Monaco. Monaco is bad everywhere, yes, haven't you watched the wet races? Not many finishers...
I might note that we have a TDF variable called "Roughness" which defines the micro and macro roughness of the surface. Higher values indicate more sharpness at the given scale. At some point this will be documented a bit more clearly, but it should help achieve some of the effects described, in addition to others like the difference between concrete and asphalt and the type of aggregates used, etc. Note also that different tire compounds can be tuned to specific surfaces.
I understood the "Wrong", only. Your authoritarian approach deserves a better (or understandable) explanation, to say the least.
Oh, I thought this was locked! Anyway: Great to hear. =) Nobody is talking about street tyres and race tyres, just temporary street tracks and dedicated race tracks. The surface of a street track tends to wear more evenly because people don't just drive on a single line (though if being pedantic about it one should make the middles of the lanes even more worn, and some streets even have two very visible grooves where most people drive), whereas on a race track people at least try to hit the apex and overall follow a proper racing line.
I think Patryksok said that rubber layer on street tracks, that came mostly from street tyres, won't "cooperate" with rubber on racing slicks during race weekend. At least not as much as you expect like on closed race tracks (where rubber layed down on track come mostly from racing slicks). And that might be another reason why general grip levels are lower on street tracks. At least, that's how I understand what he said
Hmm, might very well be. Still, the point was that even if the racing line is properly rubbered in on a street track with racing tyres, the road surface is more evenly worn everywhere, so if it rains the racing line shouldn't really be that much more slippery than the off-line. That the difference in grip in wet conditions between the racing line and the off-line isn't so much because the racing line has rubber in it, but that the off-line is more coarse and less worn than the racing line. That is of course assuming that the hypothesis in the article is a valid hypothesis, and they're not just talking out of their arses. =)
The thing with a race track is that there is an off line, on a street there is no off line (traffic goes everywhere), so it's all relatively smooth, and all as slippy as the racing line is on a race track. We've seen wet races at Monaco, they don't end with many cars running.
