Pirelli has moved to defuse the fuss about the Mercedes Barcelona test by postponing the planned switch to the revised rear tyres until Silverstone.
The company had intended to make the switch from steel to Kevlar belts – as used last year – for the Montreal weekend.
However, the news that Mercedes potentially gained an advantage by trying them during the test after the GP in Barcelona made the early introduction less tenable. Instead Pirelli will provide the teams with sets of the new tyres for evaluation on Friday, thus allowing everyone to sample them before the earliest introduction at Silverstone.
Nevertheless the change remains contentious because as outlined on this blog yesterday some teams have been able to gain performance by running the rear tyres on the wrong side, and have adjusted their car set-up to make it effective.
This technique will no longer be relevant because the left and right Kevlar tyres are identical, and this swapping will make no difference.
It remains to be seen whether the teams most affected will continue to argue their case with Pirelli and the FIA before Silverstone on the basis that it is a change of specification, which requires unanimous agreement. However that condition is trumped by a change on safety grounds.
Adam Cooper F1 
As I understand they couldn’t have changed the tyres anyway, that would have needed agreement from all teams or it had to be for safety reasons and Hembry had supposedly said “It’s important to point out that these delaminations, which occur when the tread comes off, do not compromise the safety of the tyres,” and all the teams had not agreed.
Not to mention that a 1000 KM test session vs. running one set during a FP is hardly comparable. Either Pirelli and Mercedes must have been delusional to think that the test would remain a secret or seriously misjudged the outrage that would result when word got out. This is one of those cases where you ask yourself; what were they thinking?
more like, what were they smoking?
I don’t think this will diffuse anything. Ferrari & Red Bull lodged the formal protest – Red Bull want a revised tyre, Ferrari don’t. The FIA need to deal with the issue as quickly as possible. Nothing else will satisfy every team.
Payback by Pirelli for RBR because they’ve lodged a complaint about the testing (and also said some fairly vocal things about the current tyres) ??
I fear the longer we have the current tyres the longer we’ll not see anyone really racing, and that’s pretty depressing for a fan. The only time of a GP weekend where we really see the top drivers going for it is Q3, 2 hot laps per race meeting… nice.
Is the de-lamination down to this left right swapping?
That is a great question!
I think if the swapping was a factor then Pirelli would have said so, as they did when tyres were used with wheels set to a more severe camber than they advised.
Am trying to find out. Pirelli didn’t answer when I asked today…