48 replies to this topic

[B. Dover]

According to www.turunsanomat.fi, Michelin used a special kevlar-reinforced tires at Monaco and that was the reason why Michelin-based teams were so fast.

According to the paper, the kevlar prevented the tires from 'bouncing' too much (=made them more firm) and thus improved the handling in corners. Because of these kevlar-reinforced tires, JPM and KR were forced to start with lower tire-pressures so in the start they were not working optimally but as the tires warmed up, they started working perfectly.

[Viss1]

Interesting if true... Monty said he and Ralf were running different tire pressures, which may account for Ralf's performance in qualifying and Monty's in the race.

[Jhope]

Kevlar reinforced tires are what Michelin used when making tires for the Concorde. There was rumour last season that they were developing a tire based on this construction method.

[baddog]

Originally posted by Viss1
Interesting if true... Monty said he and Ralf were running different tire pressures, which may account for Ralf's performance in qualifying and Monty's in the race.

tyre pressure can Im sure be adjusted between qualifying and the race. in fact it must adjust itself overnight and need 'tweaking'. so the race tyre pressures wouldnt affect qualifying.

Shaun

[Ross Stonefeld]

The tires should be at their optimum pressure sitting on the grid since they have tire warmers.

[A3]

If it were true, wouldn't it be illegal?

Article 76b from the International Sporting Regulations:

each tyre supplier must undertake to provide no more than two specifications of dry-weather tyre to
each Team at each Event, each of which must be of one homogenous compound ;

[kos]

Why would it be illegal? This rule only states that tyre compound must be homogenous, it says nothing about tyre carcass' construction at all.

[pRy]

Originally posted by Ross Stonefeld
The tires should be at their optimum pressure sitting on the grid since they have tire warmers.

I doubt there is a tyre warmer in excistance that could get a tyre up to the same temp as it would being actually used.

[A3]

My English is not that good. I thought "compound" meant the entire tyre material. Apparently not.

[Ross Stonefeld]

Tire warmers get pretty close to 200degrees F

[confucius]

What's that in celsius? About 80?

[Jacaré]

Originally posted by pRy


I doubt there is a tyre warmer in excistance that could get a tyre up to the same temp as it would being actually used.

they get to a temperature which can get quite near to optimum pressure, but the smaller final pressure increase only happens once the tyres reach racing temperature

[MrBreaker]

Originally posted by A3
My English is not that good. I thought "compound" meant the entire tyre material. Apparently not.

Your english is fine, compound does mean the entire tyre material. Kevlar is used to reinforced to the rubber (i.e. mixed together to make one compound). An easier way to think about it is if you have some cranberry juice, and some vodka (both are drinks). Once you mix them together, you have yourself a cape cod......which is still a drink. I'm guessing that the homegenous aspect comes into play if the sidewalls were made of kevlar, and the rest of the tyre rubber.

[maclaren]

Originally posted by Ross Stonefeld
The tires should be at their optimum pressure sitting on the grid since they have tire warmers.

So what does this fix? It has no effect on "real" pressure.

[kos]

Compound is not entire tyre material. Tyre is made of several different components, one of which is compound (resin, roughly speaking). I think that there's no use of mixing kevlar fibres into compound. What Michelin has probably done, is that they replaced some of the polyester plies in the tyre's carcass with kevlar ones.

[A3]

Originally posted by MrBreaker


Your english is fine, compound does mean the entire tyre material. Kevlar is used to reinforced to the rubber (i.e. mixed together to make one compound). An easier way to think about it is if you have some cranberry juice, and some vodka (both are drinks). Once you mix them together, you have yourself a cape cod......which is still a drink. I'm guessing that the homegenous aspect comes into play if the sidewalls were made of kevlar, and the rest of the tyre rubber.

Ahh, cheers.

[François Bonaparte]

no no no they don't cheat. they only cheat if they would do it for an particular Red team.

[Ross Stonefeld]

Originally posted by maclaren

So what does this fix? It has no effect on "real" pressure.

Dynamic pressure is a function of heat. As the tire warms the pressures go up. If the tire is allready warmed the pressures are allready up.

[Crazy Canuck]

Originally posted by Jacaré

they get to a temperature which can get quite near to optimum pressure, but the smaller final pressure increase only happens once the tyres reach racing temperature

Because the warmer only heats the tire surface. Driving heats the breaks, which heats the Rim and the warm RIM adds additional heat to the system.

CC

[Sir Frank]

So, has this been the first time this kind of construction was in use? Is this construction gonna be used on other tracks as well? Is it an improvement only in slower corners mostly?

[Jacaré]

is kevlar as revolutionary for tyres as it was in sails for competitive yachting?

[Viss1]

Originally posted by baddog
tyre pressure can Im sure be adjusted between qualifying and the race. in fact it must adjust itself overnight and need 'tweaking'. so the race tyre pressures wouldnt affect qualifying.

Right, but Ralf and Monty might have been trying different strategies to work with the new compund.

[Dudley]

no no no they don't cheat. they only cheat if they would do it for an particular Red team

That would be you crossing the line between discussion and pure troll.

[mudpuppy]

Not to get off topic of tire temps and materials, but I was wondering why Bridgestone did what they did....

They had a monopoly on tires a few years ago, which meant that when Michellin decided to come back, they had to try to convince the top teams to switch. At that time McLaren were still using Bridgestones. The McLaren was featured in all their TV ads. And it was not until Bridgestone decided to collude with Ferrari did McLaren (naturally) felt that they HAD to switch to Michellin, despite the fact that they were much slower tires and a lot less consistent. In other words, Bridgestone gave McLaren the boot.

Fast forward to 2003. After a winter of intense tire testing and data analysis Michellin come storming back. Now Bridgestone are at best, on par with Michellin, if not a little behind. Even if Bridgestone are still a better tire, Michellin is clearly benefitting from the marketing exposure by winning races, either with McLaren or Williams. And what about Bridgestone? In front of the media Schuey says "our car is still the fastest, but our Bridgestone tires lost us the race" - or something to that effect. And Bridgestone, despite investing so much money and time with Ferrari, are left to defend their brand reputation alone. And if Michellin ARE a better tire now, then how long until Ferrari also switch????.......

[baddog]

Originally posted by Viss1

Right, but Ralf and Monty might have been trying different strategies to work with the new compund.

the might.

ross, Im sure you are right, but the teams still must check and adjust tyre pressures prior to the race right?

Shaun

[MrBreaker]

Originally posted by mudpuppy
Not to get off topic of tire temps and materials, but I was wondering why Bridgestone did what they did....

They had a monopoly on tires a few years ago, which meant that when Michellin decided to come back, they had to try to convince the top teams to switch. At that time McLaren were still using Bridgestones. The McLaren was featured in all their TV ads. And it was not until Bridgestone decided to collude with Ferrari did McLaren (naturally) felt that they HAD to switch to Michellin, despite the fact that they were much slower tires and a lot less consistent. In other words, Bridgestone gave McLaren the boot.

Fast forward to 2003. After a winter of intense tire testing and data analysis Michellin come storming back. Now Bridgestone are at best, on par with Michellin, if not a little behind. Even if Bridgestone are still a better tire, Michellin is clearly benefitting from the marketing exposure by winning races, either with McLaren or Williams. And what about Bridgestone? In front of the media Schuey says "our car is still the fastest, but our Bridgestone tires lost us the race" - or something to that effect. And Bridgestone, despite investing so much money and time with Ferrari, are left to defend their brand reputation alone. And if Michellin ARE a better tire now, then how long until Ferrari also switch????.......

I think your comments raises a fewquestions. Did Bridgestone shoot themselves in the foot by colluding with Ferrari? I mean, if they ran their operations like Michelin, then they'd have 2 top teams using their tyres instead of one. More top teams using their brand means more chances that your tyres will be on the car that wins the race. Now, Bridgestone only has Ferrari to look to in order to get race wins (barring extreme circumstances such as Brazil). What other Bridgestone runner has a chance? Sauber, Jordan? As for Michelin, they have both Wills and Macs as possible race winners. Personally, I'm guessing Ferrari will stay with Bridgestones since they have a HUGE amount of input into how the tyre is constructed. But, I guess we'll have to wait and see.

[theunknowncomic]

Sorry to contradict you guys but a tyre is made up of a number of components and the compound relates ONLY to the tread area. There are numerous different types and styles of "rubber" used in various bits of a tyre from the bead, innner liner, side wall, shoulder etc.

Most racing and high performance tyres are made up entirely of man made rubber rather than the natural stuff.

Kevlar has been used in high performance road tyres for at least 10 years but usually in the bead area or as a replacement for the steel belts. The Michelin "secret weapon" can only have been in the construction or a different type of kevlar belt that reduces tyre temp or wear. Designing tyres that work properly is about 80% art and 80% science.


Back to your work now


David

[HSJ]

Originally posted by Ross Stonefeld


Dynamic pressure is a function of heat. As the tire warms the pressures go up. If the tire is allready warmed the pressures are allready up.

Maybe, maybe not. I've heard noises to the effect that in fact the tyre warmers don't get the tyres to optimal temp just like that. Or maybe it is the fact that they have to sit on the grid and do a slow parade lap before the race that cools the tyres some. We've all seen them to warm tyres during the parade lap. Fact is that KR said that his tyre pressure was adjusted in such a way that it would take a while for the tyres to work optimally. He's not the only one. I doubt it is a case of brain-fade, that they don't know what they're talking about.

[Jhope]

Originally posted by HSJ


Maybe, maybe not. I've heard noises to the effect that in fact the tyre warmers don't get the tyres to optimal temp just like that. Or maybe it is the fact that they have to sit on the grid and do a slow parade lap before the race that cools the tyres some. We've all seen them to warm tyres during the parade lap. Fact is that KR said that his tyre pressure was adjusted in such a way that it would take a while for the tyres to work optimally. He's not the only one. I doubt it is a case of brain-fade, that they don't know what they're talking about.

Case in point...Juan understeering at the Hotel Hairpin on his out lap after his first stop. Next lap around, minor understeer, then third time around spot on.

[Terramax]

quote from A3

If it were true, wouldn't it be illegal?

Article 76b from the International Sporting Regulations:


quote:
--------------------------------------------------------------------------------
each tyre supplier must undertake to provide no more than two specifications of dry-weather tyre to
each Team at each Event, each of which must be of one homogenous compound ;
--------------------------------------------------------------------------------

And of course, Minardi are on Bridgestones ....

If they were on Michellins still, would it be illegal?

[Jacaré]

Originally posted by theunknowncomic
Kevlar has been used in high performance road tyres for at least 10 years but usually in the bead area or as a replacement for the steel belts. The Michelin "secret weapon" can only have been in the construction or a different type of kevlar belt that reduces tyre temp or wear.

thanks for that explanation

[Pioneer]

Originally posted by Terramax
quote from A3


And of course, Minardi are on Bridgestones ....

If they were on Michellins still, would it be illegal?

Can you clarify that? I don't understand.

[B. Dover]

Originally posted by theunknowncomic

Kevlar has been used in high performance road tyres for at least 10 years but usually in the bead area or as a replacement for the steel belts. The Michelin "secret weapon" can only have been in the construction or a different type of kevlar belt that reduces tyre temp or wear. Designing tyres that work properly is about 80% art and 80% science.

The kevlar was used to make the tires 'stiffer' (=less 'wobbly' in corners). According to the article, it had nothing to do with tire temps or wear.

[Jacaré]

Originally posted by B. Dover


The kevlar was used to make the tires 'stiffer' (=less 'wobbly' in corners). According to the article, it had nothing to do with tire temps or wear.

so it's in the sidewall?

somehow this material allows the tyre to work with lower pressures, by achieving wall stiffness through mechanical (not air) support, and hence with lower pressure the tyre works at a lower temperature throughout the stint, causing the compound to last longer?

[B. Dover]

Yes, the kevlar was used in the sidewalls (is that the official term for the sides of a tire?)

I think the idea is that you start it with low pressure but because of the stiffer sidewalls it's able to perform relatively well despite the low pressure (unlike conventional tire) but it reaches the optimum after few laps when the temperatures and pressures go up. If you start with high pressures, in few laps the pressures might become too high (thus worsening the performance) which might explain RS's problems.

When it's in optimum temperature & pressure, the extra stiffness gives good cornering abilities and allows softening the suspension for the bumpy parts of the track so in theory the tire gives an advantage in corners where you are taking the kerbs hard.

[ScudBoy]

Originally posted by theunknowncomic
Designing tyres that work properly is about 80% art and 80% science.

......and your left with 60% excess tire

so did you mean 80% art or 20% art?

[Dmitriy_Guller]

I would also think that stiffening the tire would give more control to the engineers on setting up the car. They can adjust stiffness of each corner more precisely by tuning suspension, rather than have the damping done mostly by unadjustable tires.

[Terramax]

quote from Pioneer

Can you clarify that? I don't understand.

A3 is a Jos fan. Minardi were on Michellin's last year. I don't think he would mind if the Michellin tyre was illegal if Minardi were still using them.

Must have been why Jos did not win at Monaco

[marion5drsn]

Question ; How long has Kevler been used in bicycle tires? M.L. Anderson

[Eau Red]

Originally posted by marion5drsn
Question ; How long has Kevler been used in bicycle tires? M.L. Anderson

i think since the mid/late '80s.

[Katos]

On a related subject, is it illegal to have cockpit adjustable tire pressures. I ask because in the nineties Michael Andretti's CART team used a pressure relief system whereby they could run a higher initial pressure then gradually bleed off some pressure as the tires heated up. I believe it was only used in preseason and banned before the start of the season.

[xfire]

Kevlar was developed by Dupont in the mid 70s. It's fisrt industrial application was for radial tire carcusses. Kevlar fibers cut themselves when a bundle are flexed. The stuff failed as a good mateial for the belts in street tires.

Kevlar is 1/5th the weight of steel. Maybe they can use a lot more kevlar than steel, or make it a lot stiffer than polyester.

I'd guess they build tires the same weight as normal, but with some kevlar belting.

We first used kevlar for ropes in sailing in the 70s, then for sails. We don't use it much anymore as Spectra doesn't cut itself, and is nearly as strong and stiff.

It is used in fabric form for some portions of hulls. In a laminate it fails in compression at the same strength as fiberglass. But in tension it is very very strong.

[Pioneer]

Yes it is... adjustable suspension is banned and it is defined by the tech regs that the complete wheel and tyre is considered part of the suspension.

[Jacaré]

Originally posted by Eau Red


i think since the mid/late '80s.

is Kevlar used in bicycle tyres mainly to prevent punctures?

[KenC]

Originally posted by Jacaré

is Kevlar used in bicycle tyres mainly to prevent punctures?

Well, not as I recall. I thought my tires had kevlar beads(the part of the tire that touches the rim), which made them a b*tch to put on the rims, as there was so little stretch!

[KenC]

Originally posted by Katos
On a related subject, is it illegal to have cockpit adjustable tire pressures. I ask because in the nineties Michael Andretti's CART team used a pressure relief system whereby they could run a higher initial pressure then gradually bleed off some pressure as the tires heated up. I believe it was only used in preseason and banned before the start of the season.

Sort of like mini-popoff valves. Very ingenious and I thought it would be good for safety, as CART does not use tire warmers.

[Sir Frank]

Maybe the advantage also comes from reduced weight. I dont know what Michelin had been using before Monaco, but their tyre was stiffer than Bridgestones in the side walls, which was helping the suspension. This has been the design philosophy of Michelin, but for this increased stiffness they were also paying a weight penalty of an estimated 0,5kg/tyre. Which adds to the rotating mass, that is a lot more critical than unsprung mass. (I dont know if I used the correct words, sorry for my bad techical English)

[KenC]

Originally posted by B. Dover
According to www.turunsanomat.fi, Michelin used a special kevlar-reinforced tires at Monaco and that was the reason why Michelin-based teams were so fast.

According to the paper, the kevlar prevented the tires from 'bouncing' too much (=made them more firm) and thus improved the handling in corners. Because of these kevlar-reinforced tires, JPM and KR were forced to start with lower tire-pressures so in the start they were not working optimally but as the tires warmed up, they started working perfectly.

Well kevlar would stiffen the sidewalls of a tire. So, if you don't change the suspension rates, you'd get an even bouncier car. Obviously, tires and suspension must be taken as a whole, and stiffer sidewalls, like having shorter sidewalls, would put more of the suspension work on the actua suspension arms, and less on the sidewall flexing. This of course, requires the teams to work harder on suspension setups, more than ever, to take advantage of the stiffer sidewall tires. If you don't, then the cars will likely be slower due to all the bouncing!

I imagine that stiffer sidewalls, leading to better cornering performance, meant that more force was being opposed by the better mechanical grip in the corners, and thus more heat energy transferred to the tires, raising air pressures more than without kevlar-reinforced sidewalls. Thus, the lower cold pressures to begin with.

Also, don't lower initial temps, lead to higher operating temps? Isn't this what happened with those Ford Exploder tires? So, perhaps JPM and Kimi, by choosing lower initial temps, were getting higher operating temps, than Ralf, who chose a higher initial temp, and a lower operating temp. One would think at his subsequent pitstops that he would change his tire strategy, as one of the common race tweaks is to adjust tire pressures.

[Melbourne Park]

Originally posted by xfire
Kevlar was developed by Dupont in the mid 70s. It's fisrt industrial application was for radial tire carcusses. Kevlar fibers cut themselves when a bundle are flexed. The stuff failed as a good mateial for the belts in street tires.

Kevlar is 1/5th the weight of steel. Maybe they can use a lot more kevlar than steel, or make it a lot stiffer than polyester.

I'd guess they build tires the same weight as normal, but with some kevlar belting.

We first used kevlar for ropes in sailing in the 70s, then for sails. We don't use it much anymore as Spectra doesn't cut itself, and is nearly as strong and stiff.

It is used in fabric form for some portions of hulls. In a laminate it fails in compression at the same strength as fiberglass. But in tension it is very very strong.

Top boats now use little Kevlar, as carbon like F1 cars use carbon fibre materails and even in sails carbon is replacing kevlar. Also boron fibres have superior characteristics to carbon in some areas but are worse in other areas. I'd expect F1 cars to have boron fibres in some areas, as long as its permitted.

As to kevlar in F1 tyres, maybe its some new form of the fibre that's superior.