Pirelli’s head of F1 and car racing believes two high-speed crashes at the Azerbaijan Grand Prix were due to debris on the track and not tyre wear, but added it appeared Lewis Hamilton also had a cut in his tyre after initial investigations.
Aston Martin’s Lance Stroll and Max Verstappen were involved in terrifying similar-looking crashes in Baku, with both walking away unharmed, but the race was essentially thrown into disarray.
On lap 30 of the race, Stroll appeared to suffer a blowout near the pit entry as he edged towards top speed, and hit the wall hard, bringing out a Safety Car.
Verstappen meanwhile was leading with five laps to go when disaster struck not too dissimilar to Stroll, with his left-rear tyre appearing to give way, catapulting the championship leader into the wall at 200mph.
The crash brought out the red flag, with the race then effectively becoming a two-lap sprint race to the end after a half an hour break.
Mario Isola told the media: “I believe I can exclude that failures were due to tyre wear because it’s not a matter of tyre wear.
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“The rear-left tyre is not the most stressed tyre in Baku because it’s obviously the rear-right.
“I don’t want to give any preliminary conclusions. But it seems that it is a cut due to debris, because as I said, it’s not the most stressed tyre.
“We had other cars with the same number of laps [on the] same tyres without any issue. So the preliminary investigation is that it is probably due to an external factor, or debris, or kerb or whatever.
“Another element was there was no sign, or any warning according to the teams,” Isola added. “We have to receive the telemetry from them but what they told us was that there was no warning, no vibration nothing to seem that there would be something [wrong] in the tyres.”
“For Max, it could be debris from Lance’s car,” continued Isola. “For Lance, honestly I don’t know because there were no incidents before his crash, so I cannot exclude that there was a part of something on track.
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“In 2018 if you remember, Bottas picked up a big piece of debris on the main straight and he had the same problem with the sudden deflation.
“In that case, it was visible from the images, and we could see clearly the piece of debris that was cutting the tyre. In this case, it’s a bit more complicated.
“Obviously another element of our investigation are images and if there is any camera, any image, any video, any footage that we can use to better understand what happened [we’ll use it].”
Hamilton had his own woes in Baku, with Mercedes chief Toto Wolff admitting the seven-time world champion accidentally pressed a ‘magic button’ on his steering wheel that alters brake balance.
“We found a cut on the inside shoulder on the rear-left tyre used by Lewis Hamilton in the same stint [as Verstappen],” said Isola.
“The cut was quite deep and big, probably 6-7cm, but not cutting the construction, so the tyre was still in one piece, just with this cut.
“And when there was the red flag and Lewis and came to the pit lane and changed the set of tyres, we were able to find the cut in the tyre.”
A full investigation will now take place ahead of the French Grand Prix as to what happened, with a report expected in Paul Ricard for all teams.