Quick question - tyre change

At Rockingham yesterday for the great racing, but noticed that after the green flag lap most (all?) of the teams changed the postion of the tyres on the car. Why is this?

Surely one lap cannot cause uneven wear. Presumably there's a very good reason, an I'd be interested to know (also reminded me how good it was with pit stops, but that's another question!)

Thanks

im pretty sure its because on the outlap they warn up the front tires,


when they stop they change and put these on the rear as the rears are harder to warm up,

i think^^

Yep. Front wheel drive cars find it harder to get heat into the rears so they try and get as much heat in them as possible, so then change them over. Of course, on a rear-wheel drive car the reverse happens ( with the front taking longer to warm up)

Thanks - I knew there woud be a simple answer.

Presumably then the tyres hold their heat for the five minutes or so they sit on the grid after the green flag lap and the tyre changes? I'm just wondering whether it's worth it (although it obvioulsy is as they do it!).

I know that looking at the used tyes in the garages, it looks as though they've almost melted, and you always see the chaps with the 'hair dryers' giving them a shave between races!