Pirelli tires being redesigned after F1 race failures

MILAN, Italy—Pirelli Tyre S.p.A. is blaming the explosive race tire failures at the June 30 British Grand Prix Formula 1 race on a combination of tire mounting and pressure irregularities, overly aggressive camber settings and “aggressive” curbing in a number of left-hand turns. “What happened at Silverstone was completely unexpected and it is the first time that has occurred in more than a century of sports history of Pirelli,” said Paul Hembery, Pirelli's motorsport director, referring to the four explosive tire failures during the Grand Prix at Silverstone, England. As a result, Pirelli is asking F1 racing's sanctioning body, the Federation Internationale de l'Automobile (FIA), to work with the sport's teams to ensure that Pirelli has “full access” to the teams' tire-relevant data so as to foster proper development and use of the race tires. Pirelli also said it will revert to using aramid belts for the rear tires to be used at the July 7 Grand Prix of Germany, replacing the steel-belted versions used up to now this year. As the tire's basic design is asymmetrical, however, teams will only be allowed to mount the tires in the wheel position designated, Pirelli said. The tire make said it also intends to redesign the range of tires to be used the remainder of the season to incorporate a symmetrical structure—based on the 2012 construction but using the 2013-spec compounds. The redesign will be tested July 17-19 at the Silverstone circuit, where the FIA will allow current F1 drivers to participate in what was originally scheduled to be the “young driver test.” Data gleaned from these tests will be used in the final development of the new range of tires, Pirelli said. Regarding the failures at Silverstone, Pirelli cited four causes: c Reversed mounting of the rear tires, namely the placement of the tire to the right instead of the left and vice versa. The 2013-spec tires have an asymmetrical structure and are not designed to be interchangeable; The sides of the tires are constructed so as to support stresses of different nature between the inside and the outside, Pirelli said. The inversion of the tires compromises, in certain conditions, the optimal functionality. c The adoption of tire pressures too low or at least lower than those provided by and recommended by Pirelli. The underinflation increases the stresses the tires are subjected to; c The adoption of “extreme” camber angles; and c Curbs particularly aggressive in fast corners, like Turn 4 at Silverstone, the scene of most of the failures, which not coincidentally involved the left rear tire. Pirelli also lauded the FIA for agreeing to institute more preseason winter testing and for making it possible to conduct tests during the season with cars of the current championship.