Tyre speed

[sonofzelda]

If an S2000 touring car with good tyres is travelling in dry conditions along a straight at a steady 120 mph what is the speed, in the direction of travel, of the part of the tyre in contact with the ground at any instant in time? And what would it be for a BTC spec car?

[FlashGordon]

Erm im guessing the bit about the BTC car the speed would be the same.

[CharlieJ]

Nice one sonofzelda - in theory, the bit that's in contact with the ground is actually stationary. :D

[sonofzelda]

Strange but true! I'm told that apparently there is a little-known clause in the S2000 regulations which says "any car contravening the laws of physics will be ineligible for entry". The BTC rules lack a similar caveat which is why, I assume, they are being phased out.