Pirelli issue two statements regarding cause of Silverstone tyre problems

After exhaustive analysis of the tyres used at Silverstone, Pirelli has concluded that the causes of the failures were principally down to a combination of the following factors:

 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.

2) The use of tyre pressures that were excessively low or in any case lower than those indicated by Pirelli. Under-inflating the tyres means that the tyre is subjected to more stressful working conditions.

3) The use of extreme camber angles.

4) Kerbing that was particularly aggressive on fast corners, such as that on turn four at Silverstone, which was the scene of most of the failures. Consequently it was the left-rear tyres that were affected.

The only problems that had come to light before Silverstone were to do with delamination, which was a completely different phenomenon. To stop these delaminations Pirelli found a solution by suggesting that the teams use the tyres that were tried out in Canada from Silverstone onwards. When this proposal was not accepted, Pirelli found another solution through laboratory testing, with a different bonding process to attach the tread to the carcass. So the problem of delamination has nothing at all to do with what was seen in Great Britain.

 Following the conclusions of this analysis, Pirelli would like to underline that:

1) Mounting the tyres the wrong way round is a practice that was nonetheless underestimated by everybody: above all Pirelli, which did not forbid this.

2) In the same way, under-inflation of the tyres and extreme camber settings, over which Pirelli has no control, are choices that can be dangerous under certain circumstances. Because of this, Pirelli has asked the FIA for these parameters will be a topic of accurate and future examinations. Pirelli has also asked for compliance with these rules to be checked by a dedicated delegate.

3) Pirelli would also like to underline that the 2013 tyre range does not compromise driver safety in any way if used in the correct manner, and that it meets all the safety standards requested by the FIA.

 The logical conclusion is that it is essential for tyres with the performance and technical sophistication of the 2013 range to be regulated and carefully controlled by Pirelli itself. In order to ensure the optimal functioning of the tyres, the Italian firm would need real-time data from the teams regarding fundamental parameters such as pressure, temperature and camber angles. While waiting for new regulations that would permit Pirelli access to this data, vital for the development and management of these state-of-the-art tyres, the following measures are proposed for the forthcoming grands prix, in agreement with the FIA, FOM, the teams and the drivers:

1) The use of the evolution of the current tyre that was tested in Canada (and proved to be completely reliable) for the German Grand Prix this weekend. This represents the best match for the technical characteristics of the Nurburgring circuit. In particular, the rear tyres that will be used at the German Grand Prix, which takes place on July 7, have a Kevlar construction that replaces the current steel structure and the re-introduction of the 2012 belt, to ensure maximum stability and roadholding. Given that these tyres are asymmetric as well, it will be strictly forbidden to swap them round. The front tyres, by contrast, will remain unaltered.

2) From the Hungarian Grand Prix onwards, the introduction of a new range of tyres. The new tyres will have a symmetrical structure, designed to guarantee maximum safety even without access to tyre data which however is essential for the optimal function of the more sophisticated 2013 tyres. The tyres that will be used for the Hungarian Grand Prix onwards will combine the characteristics of the 2012 tyres with the performance of the 2013 compounds. Essentially, the new tyres will have a structure, construction and belt identical to that of 2012, which ensured maximum performance and safety. The compounds will be the same as those used throughout 2013, which guaranteed faster lap times and a wider working range. This new specification, as agreed with the FIA, will be tested on-track together with the teams and their 2013 cars at Silverstone from 17-19 July in a session with the race drivers during the young driver test. These tests will contribute to the definitive development of the new range of tyres, giving teams the opportunity to carry out the appropriate set-up work on their cars.

SOURCE: Pirelli Media 

Following this statement, the general consensus was that Pirelli still would not accept they were at fault, and were in fact attacking the teams (assuming they were in the wrong). Paul Hembery released a second statement once Pirelli acknowledged the response to the original statement:

Contrary to the impression that some people have formed, I would like to underline the collaboration and support we are receiving from the teams, drivers, FIA and FOM. In no way are we intending to create arguments or attack anybody. We have taken our responsibilities upon ourselves as our press release indicates. But not having full control over all the elements that impact on the use of the tyres, we need everyone's contribution. With regard to this, we are receiving the full support of all the parties involved, for which we are very grateful.Paul Hembery

While I don't think Pirelli is completely innocent of this chaos, truth is, both the teams and the FIA are partly to blame.

First, Pirelli actually wanted to change the tyres before Silverstone, but the teams didn't allow it. Secondly, it's clear that the teams have been misusing them. While that's nothing new, Pirelli's tyres being less resistant to misuse doesn't change the fact that there was misuse in the first place. Tyres are designed for left and right sides for a reason, not decoration.

While one can argue that it was Pirelli's fault for not banning it before, they had no way to know the effects since the FIA has such stupid rules about testing. So not only does the FIA want softer tyres in order to boost spectacle (which in itself involves a risk) but they are incredibly idiotic about their testing policies (not on 2013 cars, only a team at the time, complete lack of transparency, etc).

This mess is more the fault of the near-sightness of everybody involved.

The set-ups are irregardless of the point, kipi19

Yes and no. There's not a single piece of engineering equipment that isn't designed to work under a definite set of conditions. 

Of course, when talking about something like tyres you can expect them to work under a very wide set of ones. That's why the tyres we buy (as most of the products) are designed to resist a very wide range of misuses. 

But the thing is, those tyres are tested EXTENSIVELY, and that's a luxury Pirelli didn't have, because of the oh-so-stupid FIA. The simple fact that they are not allowed to test the CURRENT set up (a 2013 car) shows how silly the whole situation is.

Also remember, the tyres are so soft in the first place because the FIA wanted them that way.