The Italian manufacturer then announced that it had come up with a more
effective bonding process to solve the issues of delamination. Pirelli’s
motorsport director Paul Hembery has already ruled out this new bonding
process out as a possible cause for Sunday’s chaos.
2. Debris on track
It is possible the blowouts were caused by debris on track, whether bits of
carbon fibre from cars which had collided or bits of tyre which had already
shredded.
This seems unlikely to be the root cause given the fact that, in five of the
six blowouts over the course of the weekend, the rear-left tyre was the one
affected.
Also, there is the fact that all the incidents occurred in two specific areas
of the track – around the Wellington and Hangar straights. This suggests
that, while debris might have been the trigger for the blowouts, the stress
on the rear-left tyres at those points on the track made them highly
susceptible.
3. Silverstone’s kerbs
The BBC’s technical expert Gary Anderson suggested in a video posted after the
race on the corporation’s website that a high kerb with a sharp edge at Turn
Four could have been responsible for at least some of the blowouts, with the
inner sidewall of the tyres vulnerable as the cars cut the corner.
This still raises questions as to what triggered the failures around the
Hangar Straight and also why the cars were not affected throughout the
weekend, for instance during Friday practice. Also why other support series
races were unaffected.
4. Heat
It was considerably warmer on Sunday than it had been earlier in the weekend,
which has a knock-on effect on the tyres.
5. A combination of all of the above
Pirelli may well find that a combination of the new 2013 compounds, the
specific characteristics of Silverstone’s high-speed track, the load being
put through the tyres, the warmer weather on Sunday, the high kerbs at
various part of the track and the debris on it all contributed to make it a
perfect storm.
But as McLaren team principal Martin Whitmarsh said, this should still not
have resulted in the dangerous blowouts we saw.
“There is debris; there are (kerb) edges you can catch with a tyre. But
there have been all the time I have been in F1,” Whitmarsh said. “You’d
like tyres that were sufficiently durable to put up with that, and you’d
like a failure mode that is perhaps less dramatic than we’re seeing at the
moment.”