Pirelli say 'mode' of recent tyre failures need looking into after Di Resta incident

Pirelli chief Paul Hembery says the Italian manufacturer's disquiet over the recent examples of tyre failures centres on the way the tread is giving way, rather than over any potential increase in problems.

Paul di Resta was forced to park his Force India on the inside of the main straight at the Circuit de Catalunya during the closing stages of Friday's second practice session in Barcelona when his left-rear tyre failed, the medium rubber losing its tread as the Scot exited the final corner.

The dramatic 'failure' appeared similar to the experiences of Lewis Hamilton during final practice in Bahrain, although the incident on his Mercedes also triggered suspension damage. Ferrari's Felipe Massa suffered two punctures of his own during the race at Sakhir.
All three of the failures in the last race were subsequently traced to cuts to the tyre caused by debris, but the Pirelli motorsport boss doesn't like the manner in which the tyres are failing.

"Historically when you look back at when we have issues with the tyres it is through cuts of debris, that is the most likely cause," he told reporters.

"The mode of failure this year is much more spectacular visually. The tyre was still inflated [on the Force India] from what I could see, so the structure didn't give way, it's the tread and that's what we've seen in a few other cases - that the tread's overheated and coming away.

"From some points of view it would be better if the structure actually gave way and then it collapsed, then it wouldn't be quite so spectacular.

"In any case it's not something that we like and we're looking at what we can do. We've had four races now so we don't look at it as an increase of issues, we just don't like the mode of failure - that's what's concerning."
Speaking in the earlier team bosses' press conference at Barcelona, Force India's Technical Director Andrew Green admitted the failure which cut short his driver's afternoon long run had been "completely unexpected".

Hembery says Pirelli's technicians need to conduct a more detail examination of the damaged tyre but that it was clear that it overheated.

"It's always very difficult because you get a back of bits back. But it's certainly caused by overheating of the tread," he added.