Formula One tyres
Tyres play a crucial role in the car's performance, affecting grip, handling, and overall speed.
Throughout the history of Formula One, tyres have undergone major changes with different manufacturers and specifications used in the sport.
[3] During the 1960s, Dunlop introduced improved nylon casings, reduced aspect ratio, significantly increased tyre width, and the use of synthetic rubber.
Therefore, from 1981 until 1992, Goodyear supplied white sidewall marked Eagle tyres with the sizes of 25.0"×10.0"–13" in the front and 26.0"×15.0"–13" in the rear.
[7] This prompted Goodyear to change to yellow sidewall markings to correspond to the new, narrower rear tyres which were approximately 12.8" wide, down from the previous 15.0".
[9] Between 1999 and 2008, regulations required the tyres to feature a minimum of four 14 mm (0.55 in) grooves in them, with the intention of slowing the cars down.
This was introduced after the first race of the season when confusion occurred because a small dot was put on the sidewall of the tyre, instead of the white stripe.
Slick tyres were reintroduced at the beginning of 2009, along with aerodynamic changes intended to shift the balance towards mechanical grip in an attempt to increase overtaking.
[15][16] Michelin, Cooper Avon and Pirelli showed interest in taking over the role of tyre partner and supplier.
On 24 June 2010, it was announced that Pirelli would be the sole tyre partner and supplier for 2011 and would receive a three-year contract.
They thus ended their programmes for both the Grand-Am Rolex Sports Car Series and FIA World Rally Championship after spending three years as an official tyre partner and supplier (as the Grand-Am Rolex Sports Car Series switched to Continental and the FIA World Rally Championship switched to Michelin tyres in 2011).
[19] In 2009, with the removal of the four 14 mm (0.55 in) grooves, the front tyres gained proportionally larger contact patch.
[22] At the 2011 Malaysian Grand Prix, Pirelli introduced a coloured band around the outside of the tyre on the softer of the two dry compounds.
On Friday, 17 June 2005, during the afternoon's practice session, Ralf Schumacher, who was driving for Toyota, crashed heavily in turn 13 of the Indianapolis Motor Speedway road course, as a result of a left-rear tyre failure.
[30][full citation needed] This pressure can cause the side walls of the tyre to bow and wear in abnormal places.
[31] The following day, Michelin reported that the tyres it had provided for its seven customer teams—BAR, McLaren, Red Bull, Renault, Toyota, Sauber, and Williams—were unsafe for extended high-speed use on this turn, and announced its intention to fly in another set of tyres from its Clermont-Ferrand headquarters.
[32] However, the replacement tyres flown in, which were of the type used in the Spanish Grand Prix earlier that year, turned out to have the same problem when tested.
[33] In a letter to FIA Race Director Charlie Whiting, Michelin representatives Pierre Dupasquier and Nick Shorrock revealed that they did not know the cause of Schumacher's tyre failure, and unless the cars could be slowed down in turn 13, Michelin's tyres would be unsafe and unsuitable for use during the race.
He also addressed several solutions which had been proposed by the teams, insisting that use of the tyres flown in overnight would result in penalties, and the placement of a chicane in the turn was "out of the question"—the race would not be sanctioned by the FIA (making it a non-championship race) if the track layout was changed.
[34] In a second letter, Dupasquier and Shorrock announced that they would not permit their teams to race on Michelin's tyres.
This change is supposed to provide teams with more flexible strategy options after criticism towards the original C1 compound for a large drop in grip compared to the other tyres.
At these races the use of tyres in qualifying will be mandated as hard in Q1, medium in Q2 and soft in Q3, assuming that the weather is dry.
