F1 INSIDER
Baku tyre fallout, Ocon’s deal and calendar update
Pirelli is to evaluate a new rear tyre design at the Austrian Grand Prix, due to take place shortly after this issue of GP Racing closed for press. The move comes as a response to the controversial failures which eliminated Lance Stroll and Max Verstappen from the Azerbaijan Grand Prix. Each driver will have two sets to evaluate during Friday practice and, if the trial is deemed successful, the new construction will be introduced at the British Grand Prix.
The new design incorporates a number of ideas, which were initially developed for the next generation of tyres that will be on the 18-inch rims coming next year. Pirelli’s aim is to make the shoulder of the rears more robust, addressing a potential weakness it has guarded up to now by setting strict limits on tyre pressures and camber angles. Many teams and drivers have complained that these pressures are too high, militating against good grip levels.
“With this new structure Pirelli provides a tyre that can guarantee even greater levels of integrity under the extreme conditions that can be generated by the current cars,” said the company in its official announcement.
Dealing with the forces generated by the current generation of F1 cars has proved problematic in recent seasons. At the 2020 British GP several drivers, including race winner Lewis Hamilton, suffered dramatic tyre failures in the closing stages. The threat of ongoing development taking the cars far beyond the tyres’ tolerances prompted Pirelli to (successfully) lobby the FIA to implement measures to reduce downforce ahead of this season.
Despite this, two different cars suffered identical failures in Baku. In Verstappen’s case it cost him victory in the race. Pirelli initially suggested debris was to blame but investigations revealed both tyres had suffered “circumferential breaks” around the outside of the tread. The tyre company claimed this was a result of the teams in question – Red Bull and Aston Martin – running the tyres at a lower pressure than they should have, which induced a “standing wave” across the surface of the tread under duress. Eventually these forces led to shearing and failure.
Running tyres at a lower pressure can increase the socalled contact patch, the area of the tyre surface which is in contact with the track. But this comes with a penalty in the form of more sidewall movement, which induces the standing wave. Pirelli’s contention was that the teams had found a way of complying with the minimum pressure requirements at the time of measurement, before the race start, but subsequently lowering them. Both Red
Bull and Aston Martin refuted this.
At the moment Pirelli does not have access to ‘live’ tyre pressure data while the cars are running, but it will next year. In the interim it hopes this new construction will enable the rear tyres to be more robust and less temperature sensitive. Naturally, though, there may be some resistance from the teams if they feel the change gives rivals an advantage, or requires costly adjustments to their own cars to achieve optimum performance. Pirelli says this should not be the case.
“On paper, the changes are not big in terms of expected behaviour,” said the company’s motorsport manager,
Mario Isola. “So I don’t think they will affect the competitive order of the teams. They have to test them and obviously they will try to understand the new tyre as soon as possible.
“That is normal, there is always a learning curve. Obviously we’re not talking about a completely different tyre. That means I’m not expecting this learning curve will be a long period. But again, we are planning to release data in order to help the teams to understand the new construction better and in a shorter time.”
Pirelli says the new tyres are not significantly heavier than the current generation, and that they will be able to run at much lower pressures. But the learning curve Isola alluded to is significant: the new Sprint Qualifying format is due to be evaluated at Silverstone on the same weekend as the new tyres, provided they are approved. This means the teams will have just one 60-minute practice session before qualifying on Friday, ahead of the sprint event on Saturday.
“That’s a curveball,” said Mercedes boss Toto Wolff. “Nobody really knows on which head it is going to detonate. You could be on the lucky side or on the unlucky side. It’s very much an unknown.
“But as long as it’s the same for everybody, we can cope.”
“THE CHANGES ARE NOT BIG IN TERMS OF EXPECTED BEHAVIOUR. SO I DON’T THINK THEY WILL AFFECT THE COMPETITIVE ORDER OF THE TEAMS”
MARIO ISOLA