BetterMakeWay

Ok...like many questions i don't have an answer yet...i was wondering in Formula 1 why do the tires have such a big sidewall? You know there is always the fact that the smaller the tire sidewall with a proper rim you can improve the car's handling and feel. The bigger the sidewalls the less cornering performane you get, and the bigger the change to unmount the tire from the rim. But that is a roule for normal cars not monopost cars like F1 cars. In other means there are defentley differences in suspension in such cars, big difference even between DTM cars or GT cars. But on the other hand the laws of phisics apply to F1 cars aswell, and even with the complex suspension settings the tire sidewalls keep playing and important role. But why so big? I assume they are free to change the % from race to race. So even on high-speed tracks you can see still, how big the tire sidewall is.
Can anyone explain this? Or share more info about it or any F1 tech infos. Thanx.

swajames

This might help, it discusses some of the reason for the sidewall (deformation so that more tire than the max permitted width hits the road)

http://www.f1technical.net/articles/1

mrbelk

Part of the reason is to limit the size of the brake disk in order to artificially reduce braking performance.

I believe that the tire sizes are generally fixed. For example, for the dry weather tires, there have to be 4 grooves per tire and they have to be Xmm deep and y% of the total width of the tire, etc. etc. There is very little, if any, latitude in altering the height of the sidewall. There are rules that govern minimum ride height, total vehicle height, width, etc.

-MrB

needforspeed

I love your questions !

The answer is regulation - which is presumably all part of slowing the cars down to safer speeds:

Here is an interview with a guy from Bridgestone who deals with F1.

http://www.f1nutter.co.uk/tech/qa_suganuma.php

Extract:

Q: Why do high performance road tyres have very low profiles, while F1 tyres have very tall sidewalls?
A: The ringside of F1 is decided by regulations, we have to use 13 inch diameter rim. From a tyre point of view, it's not necessary to be a low profile tyre. Low profile tyres provides some good change of direction but even with a F1 tyre we can give some good performance into the tyre

I'm not entirely convinced about the argument that low profile tyres are all about handling - once you go to the extent BMW have (275/30/19) then I think it's more about looking good than handling.

The z4m 'racer' (the one BMW are going to hit the nurburgring with) has much higher profile tyres than a roadgoing version - I think this proves that the BMW set-ups go beyond handling.

BetterMakeWay

Thanks for the info.

Well i do think if we look at other motorsport cars like DTM or WTCC you'll see that they have a particulary low profile tire so that they can improve the steering feel, the response, and minimise the chance to unmount the tire from the rim in heavy cornering or extreme situations. As the guy from Bridgestone said, low profile tires provides some good chage of direction.
Put it this way...do you think 2 identical bmw E60s will handle the same if one is equipped with a 16-17"rim with a 55 tire sidewall or even bigger than one with 19" with a 30% tire sidewall?