After the case of the flexible wings, the one of the tires with inflation pressures below the prescribed values bursts (it should be said). You may have noticed that, beyond Max Verstappen’s arrows after the retirement in the Azerbaijan GP caused by the failure of the left rear tire, the teams that have accused of the sagging (Red Bull and Aston Martin), have been very measured in the comments.
After the sagging of the tires of Lance Stroll on lap 29 and of Max Verstappen with 5 laps from the end, always on the rear left, Pirelli has opened an investigation to find out what caused the sagging that was repeated in the long straight of 2 , 2 km at high speed (the Canadian at 280 km / h while the Dutch was already over 330 km / h).
Mario Isola, head of four wheels at Pirelli Motorsport, in the heat had hypothesized the presence of debris on the asphalt that could have caused the failure, given that even on the left rear of Lewis Hamilton the Bicocca technicians had found a conspicuous diagonal cut that was attributable to an external element collected on the track (perhaps after the two accidents).
Pirelli has ordered microscopic tests on the damaged tires and the results are expected for the beginning of next week. The aspect to note is that the sagging came suddenly, without there being any signs of wear or degradation such as to trigger alarm signals.
The sole supplier did not limit himself to analyzing the tires of Stroll and Verstappen, but also extended the checks to the tires of those who completed the race stint with an indisputably higher distance without finding any anomalies.
And, as the Gazzetta dello Sport anticipated, some very interesting data would have emerged from the analyzes that emerged from the laboratory in Viale Sarca in Milan: the two tires would not have suffered any structural failure or due to a factory defect.
So what happened? Excluding the debris, of which no trace was found, to find an answer on the cause of the two accidents, there was a need to broaden the investigation. And the doubt that has emerged is that there are those who manage to lower the tire inflation pressure below the safety value prescribed by Pirelli: in Baku it was raised to 20 PSI at the rear, while in free practice it was 19 PSI. .
Reducing the pressure and controlling the temperature of the tires improves grip and, therefore, performance. Since the 2015 Belgian GP, Pirelli has obtained from the FIA the possibility of introducing prescriptions regarding the inflation pressure and the maximum camber angle.
The technical commissioners of the FIA check the pressures every time a car enters the track and the prescribed values are duly respected. But the speech is identical to that which emerged from the flexibility of the wings: during the static checks they respect the regulation values, while when they are subjected to increasing speed and load they move, reducing the resistance to advancement to the advantage of maximum speeds.
The tires must come out of the electric blankets at a maximum temperature of 80 degrees, but there is a concrete suspicion that there are teams that have activated systems that allow the tire pressure to be lowered well below the limit set by Pirelli, causing stress to the tires larger than expected. The investigation of the single supplier is shared with the FIA and the teams, but it is evident that the responses will spark strong controversy, since it would emerge that there are those who derive a (great) performance advantage in circumventing the prescriptions.
For the umpteenth time we enter what is the gray area of the F1 regulations: if the FIA measures an abnormal pressure it forces the team to adjust the value to the prescribed one, otherwise the driver is not allowed on the track, but no sanction for those who, after successfully passing the checks, manage to lower the tire inflation pressure.
Each team has its own pressure control sensors and the FIA can see the data in real time from the telemetry, but no one knows if those values may have been “corrected” with algorithms.
It should not be surprising, therefore, if from next year the International Federation, in agreement with Pirelli and FOM, will introduce in the 2022 regulation the obligation to mount unique TPMS systems, being able to manage the sensors in real time. In short, very careful checks will be triggered on the tires, as is already the case for the flow meter that measures the instantaneous fuel consumption of the engine.
At the French GP, therefore, we will not only discuss flexible wings and new controls, but also tires, pressures and camber angles, because the strong doubt arises that there are those who do not scruples in going under the prescriptions of security to get benefits.
And the case is destined to make noise, because the attention has turned on several teams and not just on those that have suffered the failures in Baku …