tire/wheel sizes

[beebee1000]

Maybe it's just me but some photos seem to suggest that there are different tire widths for different sanctioning bodies/race series. What's goin on? Also...what are the hot tire/compound combinations being used? Interested in both long lasting testing compounds versus balls-to-the-wall sticky rubber combos. Thanks Bee

[EYERACE]

at least for the front of an FC car, one can fit different size widths......do some organizations only let one size run? eye have no idea.
hot & sticky vs. long lasting...........an R35 Hoosier is a great combination of attributes IMHO
[by the way wouldn't we all like to be hot & sticky & long lasting? hubba hubba. ]

[Bill Kincaid]

For FC, rim widths are 6" front and 8" rear. In the pro series you will find 8" fronts and 10" rears. Pro series run on spec tires- Cooper or Hankook radials, which are a harder compound than your typical FC runs. Bias ply tires are still more common than radials in FC but that could change. Hankook Ventus radials, as used in both the East and West coast pro series, are pretty nice tires. They are super consistent dimensionally, they don't leak, and they are very long lived. On the down side they are heavy and (obviously, due to the compound) not hugely sticky. Hankook is rumored to be working on a sticky radial for FC. As you have probably observed from pictures, cars on radials run a lot more (negative) camber.