Pirelli admits allowing tyre swapping was its biggest mistake

Following its detailed investigations in to the blow-outs that struck four drivers at the British Grand Prix, Pirelli claimed that a combination of tyre pressures, camber settings, kerbs and tyre swapping caused the incidents.

Although those findings put a lot of the onus on the teams for causing the problems, Pirelli motor sport director Paul Hembery says his company has to take the blame for allowing teams to swap tyres.

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"I have to say last weekend was our responsibility," Hembery told AUTOSPORT after arriving at the Nurburgring.

"We allowed the teams to invert the tyres when we shouldn't have done.

"With the cars going much quicker this year that creates different loads. With the inverted tyres you create a weakness point, and that was the issue.

"There were secondary issues, which have been mentioned, but I don't want to take away from the fact it was our responsibility.

"Going forward, though, there are things we need to be much more rigid on, and that's where we are at."

KEVLAR SWITCH

Pirelli has introduced Kevlar-belted tyres for this weekend's German Grand Prix which, allied to pressure and camber limits and a ban on tyre swapping, it hopes will prevent a repeat of problems.

Hembery explained that the switch to Kevlar was important for several reasons, and not just for bringing down the temperature of tyres.

"The steel belt was angled in one direction which is why, when you invert it, it actually goes into a point rather than being pushed along the top of the belt. That is why it creates a weakness.

"Kevlar is not as rigid as steel, and it also operates at lower temperatures, so it gives you greater margin from that point of view.

"Of course, the severity of the Nurburgring as well is another factor."

Looking further forward, Hembery said the switch back to 2012 constructions from the Hungarian Grand Prix would also be another positive on safety terms.

"In going for the 2012 tyres, there are multiple reasons. Its resistance to standing waves is higher, it's less radial.

"It's a tyre the team all know, they've all raced with it, essentially for the last two years, so they have a lot of data and information. It makes the most sense rather than trying to adapt again to the 2013 tyre, which may create more problems."