[QUOTE=jackass;602061I'm not convinced that's right, both ski's and ice skates slide over snow and ice (respectively) because they melt the material directly beneath them and turn it into water which lubricates them.[/QUOTE]
I think its a fluid flow issue, you said it, "it melts beneath them". The design of the ski is like a F1 power boat, get to a certain speed and it rides up on the surface of the melted ice below it. A tyre is really not going to do that (until you aqua-plane of course, now that is really good fun... like ice but without the visual aid!).
The water is a consequence of the friction, a tyre just creates a bow wave, ski's etc are designed to ride that wave and plane over the surface (like the F1 boats). The water maybe lubricates or maybe exists because of the friction, but either way the ski isn't designed to slow you down, quite the opposite. We are talking of tiny amounts of water for skis too, even a car tyre won't produce a bow wave more than a few milimetres high.
But I'm always happy to listen to a better argument.
PS Andy_d makes a good point, we've sort of gotten of the thread a bit!
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