F1 teams to test slicks at Jerez!!!

[modbaraban]

I wonder how BS gonna mark the softer compound of slicks?

[Carlos]

Well, the contact patch of any tire is very small, once you cut those wide, deep grooves into them, that contact patch shrinks, almost like comparing a thong to briefs and as soon as you do groove a tire the drivers complain all season long how "nervous" the car is under braking, how it "skates" and "skewers" and "slides & slips" towards an apex, it's almost beyond a fan's humble endurance. Slicks have a larger contact patch, yielding more traction under acceleration, better adhesion cornering, braking is more effective. A slick can use a softer compound than a grooved tire because the treads don't shimmy and shake like grooves do, which generates heat and with heat the tires start to throw chunks all over the place so you have to use a stiffer compound with grooved tires. Yes, a slick with a soft compound sheds a lot of rubber, but not in chunks, so when a driver goes off, he can blame "the marbles" ... it's all about the drivers.

I want you to know... I laughed a lot; a comic's best moments aren't nailing a joke with perfect timing, driving an audience to near asphyxiation chuckling as they black out... no , no ...the best thing to watch is another comic bomb, die on stage, but then I have to nod in admiration because you turned a comic's death knell into a routine, a pretty good one; my respects.

[Ogami musashi]

Above technical aspects, you should see the purpose of return of slicks in 2009.

It is meant to increase the mechanical (but in fact will increase the grip short...bit it from aero or mechanical grip) grip so i think those slicks won't be just like grooves performances like.

Don't forget that the slicks tested in december are not the one that will make it in 2009.

Anyway we'll see.

[Carlos]

Yes, your right - Ogami musahi - The new rules increase mechanical grip a little (slicks) then take away 50% of aero grip ('clipped wings&things') The overall effect is a lot less grip. My post was simple. Just about the tires. Your other intimation about tire construction and materials. The new rules could even result in slick tires that gives less mechanical grip than grooved tires. We will wait and see.

[mahesh248]

Well bring slicks back means more grip for sure , will the dimensions of the wheel differ , this will be really interesting , the level of chamber used will be less , would be really interesting to know what thesee guys will be doing with the all slick tyre . Hmmmm Cool Haaa!

[Chubbs]

im confused... i recently went to race vehicle dynamics lecture at uni and learnt that the contact area of a tyre has no effect whatsoever on the level of grip... therefore the hype about slicjks is a bit of a joke... they will be harder to warm up, and therefore offer less grip in certain circumstances such as SC. Couple this with the ban of tyre warmers and i really dont understand how the FIA are increasing the level of mechanical grip to aid overtaking with these steps.

[Ogami musashi]

Would you develop the contact area thing?

It is true that contact area is not the question, but there's a question of how much force can be transfered via the two forces a tires deliver (indentation and chemical links).

But i lack knowledge on tires definitely.

so if you don't mind explaining it...thanks.

[countersteer]

Has there been any discussion in increasing the wheel diameter to something more "modern".

An increase in wheel diameter to 15 or more inches would serve to:
1. make the technology developed more applicable to current road car tire construction.
2. reduce the tire sidewall's effect on the suspension of the car. That is, place more of an emphasis on the suspension of the car itself rather than the sidewall of the tire.

I think IRL and Champ Car's wheels are 15 inch in diameter.

[Carlos]

These 3 excerpts on racing and high performance tires are well worth reading and discussion:
http://insideracingtechnology.com/tirebkexerpt1.htm
http://insideracingtechnology.com/tirebkexerpt2.htm
http://insideracingtechnology.com/tirebkexerpt3.htm

[Ogami musashi]

Again much much appreciated carlos!

For the tires diameter, it will be increased but to 14 inches. (was at 13 now)

[rsfocus]

didnt minardi run some avon slicks in testing at the start of 2001? (or thereabouts) it was verstapen driving, all came about as neither f1 tyre supplier was willing to supply them or something.

anybody have any times from back then?, you could compare the avons they ran to the normal grooved bridgestones they ended up with (if they did another run on the same circuit as the avon test)

[Conceptual]

These 3 excerpts on racing and high performance tires are well worth reading and discussion:
http://insideracingtechnology.com/tirebkexerpt1.htm
http://insideracingtechnology.com/tirebkexerpt2.htm
http://insideracingtechnology.com/tirebkexerpt3.htm

From excerpt 1:

As deformation forces and sliding speeds go up, local stress can exceed the tensile strength of the rubber, especially at an increase in local stress near the point of a sharp irregularity.

Does that not show that the grooves in the tires cause graining since the grooves increase the amount of sharp irregularities in the surface of the rubber?

Chris

[PNSD]

possibly.
it is well known that the grooves caused alot more graining, ask Giancarlo and Trulli

[Carlos]

A Little out of context Chris. The quote refers to wear and tear on a much smaller scale than graining, almost microscopic, the irregularities refer to the almost granular texture of the track surface, the stress of the rubber as it 'drapes and deforms' on a small scale, nearing a point of overload where tensile strength is exceeded and the rubber looses bonds and starts to tear, but on a very small scale, you could call it wear, smaller than tire graining, very small like that movie where they shrink a submarine very small and inject it into a guy's bloodstream so they can battle germs, I mean really,really tiny.
Graining and blisters and chunkies show up later in the practical stuff, that's still from the preliminary, theoretical stuff

[megz]

Chubbs - Contact patch has no relevance to grip? Should we race F1 cars on supermarket trolley tyres?