Max, Michelin & Maranello (merged)

[Inigo Montoya]

Right, the contact area is not constant in size or position. That is why FIA calls it a "tread width" - i.e. parts of the tyre that have been in "regular" contact, and thus show significant wear.

Can't see from that pic Adam, if the outsides look worn beyond that width... Gonna go and buy the magazine tonight

Edit: So the pic shows significant wear up to the red line?

[Peter Mallett]

So what is "regular"?

If it means as and when the tyre moves that can't be regular because (and there are rules of language here) that is a generality. Yet in the rules there is a specific that we've already discussed elsewhere.

[Adam43]

Looking at those pictures I'd be surprised is at any one moment in time there is 270mm of tyre in contact with the track.

Of course it would be hard to achieve this with any tyre, considering the camber they run, but I don't consider the Michelin to be that odd.

The Bridgestones do have more of a definite edge towards the outer edges before it then curves round like the Michelin.

I could also see how Michelin would not even think they are braking the 270mm technically or even spiritually (sic). Michelin probably think, rightly, that they never get 270mm+ contact patch. It isn't like they have thought up a clever shape that would do this - their shape is much simpler than the Bridgestone shape. Seeing this makes me believe they have just stuck with the same profile shape since 2001. However some teams complained they needed more from the fronts, so they increased the size, for them. As has been discussed this is a parameter that you change depending on whether you want a little more front grip or more straight-line speed.

Someone mentioned the cockpit rules of 1996 and I think this is a very similar situation. It is not that they are going against the spirit of the rules just that when the teams (or tyre manufactures) sat down and designed a tyre they came up with different solutions.

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My current thinking is that the Michelin teams haven't done anything wrong, but perhaps the rules perhaps need clarifying. Whether this should happen three races before the end of this season I don't know!

[Inigo Montoya]

That is what I am not sure of - thus the quotes My take, expressed in another thread, is that it should be where you see tyre wear all around the circumference of the tyre (to distinguish from scuffs from curbs, etc). But who knows for sure?

[Adam43]

Originally posted by Inigo Montoya
So the pic shows significant wear up to the red line?

Presumably this sort of analysis is at a time when the tyre could be illegal, as we know it is fine at the begining of the race.

What would have been interesting is a similar profile shot at the begining so we could see what changed, although this would not help in saying whether itis legal or not - just measure the profile and see if it is legal. It doesn't matter how it changed, just take the state as you find.

Also (again it doesn't help legaility issues, because who's to say Bridgestone are right), but it would be interesting to se a Bridgestone.

However, my main point of interest: How do you decide how far to draw the red line. In that picture you could go further. What criteria did they use to stop the line where they did. WHy not later, why not earlier.

[Adam43]

Originally posted by Inigo Montoya
That is what I am not sure of - thus the quotes My take, expressed in another thread, is that it should be where you see tyre wear all around the circumference of the tyre (to distinguish from scuffs from curbs, etc). But who knows for sure?

That is a good point. This is just one photo, taken when the tyre was in one position. Are there more at different points.

Also how do we know it is normal to the wheel? Well if it wasn't I guess this would make the tyre appear to be narrower anyway. Also maybe the grooves have been used to normalise/check this.