RE: Pirelli's Silverstone fightback

[anonymous-user]

TonyHetherington said:

Woody said:

Can't beleive that the tyres don't have 'outside' on the tyre wall - my road tyres do......

They have a rotational direction on them, and only one side can be the outside if the rotation is correct.

But swapping them from side to side doesn't alter that, the outside would still be the outside. Pirelli fit the tyres to the rims, the teams can only use them on the other side.

So much of this smacks of no one taking the blame, a concerted effort to wash over the matter by all concerned 'for the sake of the sport'.

According to what Hembery is saying, some teams had the weaker, supposed to be inner sidewall on the outside. Yet he was saying that it was the inner sidewall that was being cut by the kerbs. So would that issue have been worse if the tyres had been fitted correctly? Or did the stronger sidewall also get cut by the kerb.

Bullst......

[Agent Orange]

Pirelli said:

A SERIES OF DIFFERENT CAUSES LED TO THE TYRE FAILURES AT SILVERSTONE: REAR TYRES MOUNTED THE WRONG WAY ROUND, LOW TYRE PRESSURES, EXTREME CAMBERS AND HIGH KERBS

THE 2013 TYRES DO NOT COMPROMISE SAFETY IF USED IN THE CORRECT WAY

Given Mercedes were one of the teams to suffer a blow out doesn't this suggest they learnt or gained very little knowledge personally from the 1000KM test therefore the FIA ruling against them should be re-examined?

[stoocake]

Another believer that the tyres are fitted to the wheels for the teams, but never by the teams. Has this changed?

[crabbit]

REALIST123 said:

TonyHetherington said:

Woody said:

Can't beleive that the tyres don't have 'outside' on the tyre wall - my road tyres do......

They have a rotational direction on them, and only one side can be the outside if the rotation is correct.

But swapping them from side to side doesn't alter that, the outside would still be the outside.

Edited by crabbit on Wednesday 3rd July 10:00

[woof]

stoocake said:

Another believer that the tyres are fitted to the wheels for the teams, but never by the teams. Has this changed?

100% correct.
Pirelli fit all the tyres for the teams and each tyre is bar coded to a specific driver.

[j90gta]

Tyres are always fitted by the tyre supplier but it is up to the teams to put the wheel/tyre on the right side of the car. That Mercedes at Monaco clearly has the rear wheel on the wrong side. Would be interesting to know exactly how many of the six blowouts at Silverstone were down just to this factor. Were there any tyre delaminations/blowouts during the Barcelona test?

[STiG911]

Maybe I'm confused, but if the tyres are constructed to deal with specific loads in specific directions, it shouldn't matter which way the tyre is actually rotating. the main torsional load applied to a tyre in motion on an F1 car is surely to the left and right as the car bounces over the kerbs
I can't see a way for a slick tyre to be 'loaded' to resist forces in one rotational direction only, which is why the teams were swapping tyres from one side to the other to try and even out wear rates (which is entirely reasonable in my mind and something which can be done on road cars anyway)

[anonymous-user]

crabbit said:

REALIST123 said:

TonyHetherington said:

Woody said:

Can't beleive that the tyres don't have 'outside' on the tyre wall - my road tyres do......

They have a rotational direction on them, and only one side can be the outside if the rotation is correct.

But swapping them from side to side doesn't alter that, the outside would still be the outside.

Meaning that the outside could still be the outside, even if the rotation wasn't correct, as seen in the Hamilton pic....... And the rotation could be correct with the outside inside! Clearly!

[BertBert]

So the variables are:

outside versus inside - P fit the tyres, so unless the teams re-mount them that can't go wrong
rotational direction - if they are designed to only go one way around, you shouldn't swap them side to side (without remounting)
pressure - common to run tyre pressures at the low end of the pressure window which is risky
geo - makes a huge difference to how a tyre gets used esp camber

So it's perhaps quite easy for a team to run the tyres to the edge or even outside the operating window. So who knows?

Well a man with a lot of experience of such things I was chatting to this week has a very strong view. P race tyres are crap sayeth he. Whoever gave them the F1 contract must be nuts. P race tyres have been exploding for all time. All his opinion of course, but he does know quite a lot.

Bert

[Agent Orange]

REALIST123 said:

But swapping them from side to side doesn't alter that, the outside would still be the outside.

Pirelli said:

1) Rear tyres that were mounted the wrong way round: in other words, the right hand tyre being placed where the left hand one should be and vice versa, on the cars that suffered failures. The tyres supplied this year have an asymmetric structure, which means that they are not designed to be interchangeable. The sidewalls are designed in such a way to deal with specific loads on the internal and external sides of the tyre. So swapping the tyres round has an effect on how they work in certain conditions. In particular, the external part is designed to cope with the very high loads that are generated while cornering at a circuit as demanding as Silverstone, with its rapid left-hand bends and some kerbs that are particularly aggressive.

I read that as Pirelli saying the inner and outer side walls are strengthened for specific circuits. ie. For Silverstone with rapid left hand bends the outer wall of the left hand tyre is stronger/thicker/stiffer than the LH inner and RH inner and outer.

Swap the left and right hand tyres and you've weaker side walls on the on the LH outer where the loads are greater.

If true that sounds ridiculous. I'd have assumed all rear side walls to be of the same strength and stiffness otherwise must handle very oddly accelerating out of corners. It must be like having two differing brands of tyre on the same axle in the formula that is the pinnacle of motorsport technology.

Maybe this starts to explain why the teams have struggled to make the rears work consistently throughout and race and race to race?

[LaurasOtherHalf]

chrisw666 said:

crabbit said:

Read the press release

Instead of asking someone else to explain stuff to me? You're boring.

the slicks have steel belts yeah? steel is a good material-think of a spring made from steel-most are. so you keep squashing it & it bounces back-great eh?

now, pull the spring instead of compressing it & what happens? the steel weakens, goes out of shape & fails.

so think of the steel belts in the F1 slicks, designed to exert force in one rotational direction which all the teams did.

then swap them over to the other side-these things are obviously designed to go in one direction but have also been twisted already in that direction, something obviously had to give.

add in the high forces of silverstone, curbs & low pressures & i think you can see why they failed

[marshalla]

Agent Orange said:

I read that as Pirelli saying the inner and outer side walls are strengthened for specific circuits. ie. For Silverstone with rapid left hand bends the outer wall of the left hand tyre is stronger/thicker/stiffer than the LH inner and RH inner and outer.

Is that permitted under FIA regs ?

FIA said:

The appointed tyre supplier must undertake to provide :
a) Two specifications of dry-weather tyre at each Event, each of which must be of one homogenous compound and visibly distinguishable from one another when a car is on the track. At certain Events one additional specification of dry-weather tyre may be made available to all teams for evaluation purposes following a recommendation to the FIA from the appointed tyre supplier. Teams will be informed about such an additional specification at least one week before the start of the relevant Event.

[Donkey62]

woof said:

100% correct.
Pirelli fit all the tyres for the teams and each tyre is bar coded to a specific driver.

Although teams could request left tyre to be mounted on say right rim because Pirelli had absolutely no problems with doing that before Silverstone, for Pirelli to now say tyres are asyemetrical is total BS.

The tyre pressures FIA should enforce absolute minimum tyre pressure some teams ran below 12psi at other circuits, a fart would have more pressure than that.

[sad61t]

It's not a matter of outside-is-outside, it's a matter of left-is-left. When the left-hand rear is known to take higher loads at a circuit, Pirelli design the sidewall of a tyre intended to be fitted to the left side of the car to take higher loads than a right-hand tyre.

So long as the teams conformed to the direction of rotation flags, this asymmetry would have been OK. But, by not following the rotation arrows, the teams put the right-hand tyre on the left-hand side. This put a load on the tyre's sidewall that was outside the load envelope, with the result that the tyre blew.

[Chris Eyre]

Dear Mr Ecclestone,

It would appear that we have now reached the point where the F1 tyre allocation is insufficient.

[aussieinlondon]

Anyway you look at it, I must say I am enjoying the racing and the uncertainties resulting in the sprints at the end.

[Mini1275]

From Sniff Petrol:

Sniff Petrol said:

That Pirelli statement in full

A series of different causes led to the tyre failures at Silverstone:

- We didn’t know the cars would be driving that fast.

- Uneven wear caused by too much turning right.

- The teams repeatedly put new wheels onto the cars too quickly.

- Excessive braking, accelerating and swerving about.

- Extremely sharp leaves on track.

- Failure to proceed to approved Pirelli stockist upon kerbing tyres

- We were asked to make st tyres. Stop fking complaining when the tyres are indeed st.


A FOLLOW UP STATEMENT FROM PAUL HEMBURY

Oh God, I’m so sorry. Forget all that, forget I spoke. It’s not you, it’s me.

[Alphabravo]

Bring BRIDGESTONE back

[Gorbyrev]

All seems fair enough to me. Wouldn't like to be explaining to the insurance assessor why I had crash after a blowout on a tyre that was mounted on the wrong side. Those rotation arrows are there for a reason. But racing teams have always, and will always take advantage of any wiggle room in the rules. Great spot from Laurasotherhalf btw!

[pagani1]

Insurance companies would deny any claim where asymmetric tyres are incorrectly mounted on a vehicle. Under inflation can also mean a claim denied. What I find amazing is the teams and their geeks are happy to risk their drivers lives by incorrectly fitting and under inflating tyres and too aggressive camber angles just to find an advantage. Fernando was lucky behind one exploding tyre but he could be dead or brain damaged if he had overtaken from the other side. The FIA under Jean Dodo have been asleep at the wheel, allegedly to try and promote Michelin as next years's supplier. Pirelli should be given a huge apology from F1 and new rules should be framed to prevent tyre swapping and asymmetric tyres should continue to be the norm.
I have always used Porsche recommended Pirelli tyres on my 911 and have never had a failure-but then I checked them before every journey as motorists should. Maybe that's why I'm still alive today.
On another note-why has it taken SEVEN races for McLaren to "figure out" that changing the suspension for this years car has caused aero instability? Surely that was a major difference and should have been spotted after race 1 at the latest. Off to Nurburgring for more fun this weekend?