It is accepted that low profiles give you better grip when cornering due to less tyre wall flex yes?

Why aren't F1 tyres low profile then?

This may be a stupid question but I have been asked this many times and was never confident of my answer.

my suggestions were.

They have higher downforce therefore dont rely as much on mechanical grip.

Their tyre walls are thicker therefore dont flex as much anyway.

They run lower pressure for more grip and so need more tyre wall to provide some level of suspension.


These have always been my bulsh1tting answers, can someone tell me the truth?

[This message has been edited by Adam M (edited 13-07-2000).]

 

I didn't think they did have low profile tyres (thought it was around 70 profile)? I seem to remember one Mr Murray Walker talking about the tyres making up the majority of suspension travel as the dampers and springs are so rigid that they hardly move (something to do with aerodynamics and downforce), so the tyres have to provide some level of comfort for the driver and also help with power delivery to the road.

 

My mistake, was meant to write why aren't they low profile, have edited now. Thanks for at least some clarification. Have toask if I should believe the word of Murray Walker, famous for his mistakes.

 

A couple of reasons:

Almost all suspension travel exists in the sidewall of the tyres.

Rules - I think all wheels and tyres have to be a regulation size - though there was word of them changing it a few years back to make lower profile tyres legal. I think they abandonded this idea when they introduced grooved slicks to try and reduce grip.

Weight - metal (usually) weighs more then rubber and air, but I think F1 wheels and tyres weigh next to nothing anyway.

 

Dont forget the cars are very light, and the suspension very rigid, so lower % of weight is transfered to an individual wheel than for a road car.

robski

 

As far as I am aware it is purely because of the rules. If I can remember its a max wheel diameter of 13" but I'm not sure of the tyre dimension rule. In a sport that depends so heavily on technology I can't beleive that the teams would purposely design the suspension around the tyre flex if they had a choice.
Cheers

Justin

 

yep, there is one reson and one reason alone.

It's the rules!

The FIA have very tight tolerences on the dimensions of everything that could be performance related on the cars.

The wheels have to be 13" diameter and a set width. The tyres have to be a set diameter and width and have four grooves.

There was a fair bit of debate a few years ago about going to low profile tyres with bigger wheels as this is what the majority of road cars use but they decided to stay as is in order to limit speeds and keep the brakes under control.

CART (indycars) use 15" diameter wheels and lower profile tyres, its very easy for the teams to run 15" on an F1 car, its just not allowed.

and yes, aprox 50% of the suspension travel is found in the sidewall of the tyre, that is one of the reasons tyre presures are so critical in F1 and why ocasionally on a 2nd set of tyres the car can loose or gain some performance.

In order to control this presure to the max the teams use inert gases in the tyres and not air, this helps control the presures as the temp rises as the water vapour found in air expands with heat.