Formula One's tyre manufacturer, Pirelli, has concluded that the failures it experienced at the British Grand Prix were related to a combination of high wear levels and extreme forces.
Race winner Lewis Hamilton crossed the finish line on three wheels after his front-left tyre punctured on the final lap, seeing a lead of over 30 seconds reduced to just five seconds at the chequered flag. McLaren driver Carlos Sainz and Hamilton's Mercedes teammate Valtteri Bottas also experienced front-left tyre failures on the two laps prior.
All three drivers had their tyres fitted at the end of lap 13 when a safety car was deployed following an accident involving Alpha Tauri driver Daniil Kvayt. That set up a 39-lap stint on a single set of tyres to finish the race, which was longer than teams had planned in their original strategy.
A further 12 drivers also pitted around the same time and did not experience failures, but high levels of wear were reported across all cars.
After investigating the failures, Pirelli determined that the high wear levels caused by the unusually long stint on the tyres meant the construction had less protection against the extreme forces experienced at Silverstone, ultimately resulting in the three failures.
"The key reason is down to a set of individual race circumstances that led to an extremely long use of the second set of tyres," a statement read. "The second safety car period prompted nearly all the teams to anticipate their planned pit stop and so carry out a particularly long final stint: around 40 laps, which is more than three-quarters the total race length on one of the most demanding tracks of the calendar.
"Combined with the notably increased pace of the 2020 Formula One cars (pole position was 1.2 seconds faster compared to 2019) this made the final laps of the British Grand Prix especially tough, as a consequence of the biggest forces ever seen on tyres generated by the fastest Formula 1 cars in history.
"The overall result was the most challenging operating conditions for tyres. These led to the front-left tyre (which is well-known for working hardest at Silverstone) being placed under maximum stress after a very high number of laps, with the resulting high wear meaning that it was less protected from the extreme forces in play."
Formula One returns to Silverstone this weekend for a second race at the circuit, raising concerns about the suitability of the tyres.
However, Pirelli had already planned to bring softer tyres to the second race, which are expected to discourage teams from attempting 40-lap stints akin to the ones that led to the failures on Sunday.
In theory, the performance of the softer rubber should degrade more quickly, meaning drivers are forced into a two-stop race rather than attempting the kind of stint seen on Sunday that puts the tyre at risk.
Pirelli also confirmed that it would increase the minimum tyre pressure prescriptions to reduce the stress on tyres.