Pirelli Cites Elevated Kerbs and Atypical Usage as the Reason behind Silverstone Tyre Deflations
Pirelli, in its two statements, has explained why a series of tyres went kaput at the recent British Grand Prix. The sole F1 tyre supplier mentioned that the “sophisticated” non-symmetric built of the existing P Zero F1 slick tyres had amounted to decreased tyre pressures. This happened because team had mounted rear tyres on the other side, contrary to design specs. Moreover, extreme cambers in conjunction with high kerbs at the circuit led to totally unexpected problems.
Pirelli has released the final report of its exhaustive investigation of the multiple tyre failure incidents that occurred at Silverstone. According to it, the following are believed to be the key contributing factors to the series of tyre breakdowns.
1) Improper mounting of rear tyres
Pirelli has found that the left hand rear tyre was fitted where the right hand one should have been and vice versa, on all the victimised racing cars. The tyre maker cites this as a serious concern because their latest F1 tyres are designed asymmetrically and are non-interchangeable.
2) Abnormally Low Tyre Pressures
F1 teams had set tyre pressures lower than the minimum limit that Pirelli has set. Resultantly, under-inflated tyres increasingly flexed and bent out of condition, and suffered a boost in working under stress. It is important to mention here that Pirelli, at the moment, has zero control over such strategic decisions taken by F1 teams’ in this respect.
3) Extremity of Camber Angles
Here too, Pirelli has no power to exercise any control. It can, in no way, influence the wheel positioning angle on the track surface – the camber settings. As in the case of tyre pressures, the teams strategically decide on these settings as well, depending on their vehicle’s interaction with rubber. Pirelli has urged the FIA to accurately and more sternly examine these parameters in the future, with the aid of “a dedicated delegate” if required.
4) Insistent Kerbing at Fast Corners
Soon after the British Grand Prix, analysts and race commentators had identified a jagged edge right at turn four, exactly where some breakdowns occurred. Pirelli cites this as one of the major reasons for the undesirable impact on some of the rear-left tyres.
Moreover, Pirelli continued to assert that the latest lab-developed and tested bonding process, employed just before this grand prix, was far from being the reason behind these failures. This technique, in fact, was introduced to purge off the delamination issues that came up earlier during the season. The new method was the tyre maker’s answer to certain teams’ rejection of its suggestion to employ the latest Kevlar-belt tyre to resolve the said issue.
Paul Hembery added steadfastly that the latest range of tyres is completely safe provided that it is used correctly. However, he accepted that they had underrated the potential effects of these unconventional tyre running techniques, and hence, had not prohibited mounting tyres in a wrong fashion. Finally, Pirelli has sought greater control on the manner in which Pirelli’s F1 tyres are used, with an agreement from FIA, FOM and participating teams.