Tyre Graining

[Knock-on]

We know that graining occurs mainly in grooved tyres and hopefully we wont suffer with slicks next year.

However, why do Bridgestone make a tyre which grains so badly.

Surely, with a stock tyre, they can reduce graining by providing a fractionally stiffer compound that isn't going to move around as much.

[wedge]

Graining occurs in slicks as well. There was some talk at Le Mans this year about tyres, chunking, managing the graining phase during a stint.

The reason why there's lot of talk on graining is partly because of coverage of F1 today, the tyre wars gave us softer compounds, but mainly because its more unpredictable to manage the graining phase on grooves because of the grooves themselves, whereas on slicks the buildup generated will roll across the tyre more evenly.

[Oli_M]

Graining happens on 99.99999% of rubber tires. Its caused by the friction of the track/road surface. Its just much more prevellant in racing conditions as the higher speeds place a higher load on the tires (which are softer anyway as designed to last a specific distance).

You can't always just say "use a harder tire" as all that will tend to mean is that the cars are set up to generate more grip from aero or suspension, often increasing load on the tires and making the graining worse.

[gloomyDAY]

Graining occurs in slicks as well. There was some talk at Le Mans this year about tyres, chunking, managing the graining phase during a stint.

The reason why there's lot of talk on graining is partly because of coverage of F1 today, the tyre wars gave us softer compounds, but mainly because its more unpredictable to manage the graining phase on grooves because of the grooves themselves, whereas on slicks the buildup generated will roll across the tyre more evenly.I thought that as well, but as you can see here (http://www.itv-f1.com/photo.aspx?IM_ID=52493&PG_ID=22) that Alonso's tires are not deteriorating evenly. What gives?

[jens]

Funny enough, I remember that in the last season with slick tyres back in 1997 there were notable tyre graining issues too. Remember GoodYear teams struggling significantly at the Hungaroring for example? Although unlike now back then we had tyre war for the first time after a few years and the tyre manufacturers had to push on the limit with development.

Talking about 2009... When in the past we have usually noticed that laptimes come down during the end of stints, then this year the effect in testing so far has often been the opposite - the factor of tyre wear is outweighing the factor of the reduction of fuel amount, especially in cooler conditions (at Sakhir there weren't many problems with tyre wear). Could this give us interesting race scenarios and also interesting strategical games?

[Tazio]

Talking about 2009... When in the past we have usually noticed that laptimes come down during the end of stints, then this year the effect in testing so far has often been the opposite - There is at least one driver that has stated the exact opposite!
Sutill also says other teams are experiencing the same problem

“On the long runs they behaved quite differently and the biggest problem was with the graining.

“It happens very quickly, then gets worse and the grip never comes back.

“We are talking big differences in lap times – I have never had such a big graining issue, but I can see nearly everyone is struggling with a similar problem.”
http://www.itv-f1.com/news_article.aspx?id=45208

[Sonic]

Funny enough, I remember that in the last season with slick tyres back in 1997 there were notable tyre graining issues too.

Yeah, we could see the return of the dreaded tyre blister.


I thought that as well, but as you can see here (http://www.itv-f1.com/photo.aspx?IM_ID=52493&PG_ID=22) that Alonso's tires are not deteriorating evenly. What gives?

To be expected that a tyre will wear unevenly. Forgetting camber angles and any other setup related factors Jerez (as most tracks) has more corners in one direction that another so one tyre will have to take the load more often.

[wedge]

Yeah, we could see the return of the dreaded tyre blister.

Strange as well, Bridgestone historically tend to be conservative. In 1997 it was the Goodyears that blistered easily, Indy 2005 they opted to play safe with hard compounds.


YeahTo be expected that a tyre will wear unevenly. Forgetting camber angles and any other setup related factors Jerez (as most tracks) has more corners in one direction that another so one tyre will have to take the load more often.

Alonso's rears are in shoddy state - the left rear is slightly noticeable if you look carefully.

Tazio, I completely agree with what you said in the other thread but it seems like FOTA got it wrong.

http://www.autosport.com/news/report.php/id/72024

At this stage it seems unfair to point fingers because F1 is in completely new territory with the new regs because no one knows how to optimise the cars .

[wedge]

In case any of you were wondering, this is what a graining tyre looks like in detail:

http://www.autosport.com/gallery/photo.php/id/123356

[Tazio]

In case any of you were wondering, this is what a graining tyre looks like in detail:

http://www.autosport.com/gallery/photo.php/id/123356

Are you sure that is not a Spaniard "Blacked Up" :confused:
:rotflmao: :rotflmao: :rotflmao: :rotflmao:

[wmcot]

Slicks are subject to graining, blisters and chunking in all types of motorsport. Here's a photo I shot of used tires off the Audi R10 diesels at the Utah GP ALMS race in 2006: