The tires in Formula 1 have changed a lot in order to limit cornering speed as well as the acceleration of the single-seaters. Since the tires are of vital importance for performance, the FIA has tried numerous times to change their size, to introduce grooves in the tread to finally decide to name a single supplier in the figure of Bridgestone first (2007) and Pirelli later (2011).
In addition to reducing costs, the aim is to avoid their excessive development as happened during the compound war between Michelin and Bridgestone.
For single-seaters, the tires are the only area of direct contact with the asphalt so everything is focused on increasing grip. This factor depends mainly on adhesion and the loss of hysteresis due to deformation.
While adhesion refers to the degree of bond between rubber and asphalt, deformation consists of the adaptability of the tire surface according to the irregularities of the track. Therefore, the energy losses give raise to friction that also helps the mentioned adhesion, since the greater the surface of the rubber that is deformed to absorb the irregularities of the road surface, the greater the contact surface available for adhesion. of the compound.
During the Bridgestone years, the Japanese brand focused on the chemical composition of the compounds. The changes in the polymers meant changes in the reaction of the compound against the surface of the circuit. Processing the data of the interaction between the different compounds and the asphalt consumed the main amount of resources of the Japanese manufacturer. However, Pirelli took a different approach given its extremely different philosophy than its successor.
The degree of hardness of the tire has a direct influence on the deformation, but this in turn becomes an important development factor. The speed of the compound to deform and regain its original shape depends directly on the pressure of the rubbers, their construction and the material of the masses, this being the first factor to take into account, looking for a rapid deformation as well as a slow return to its shape. original to increase grip.
Design and Manufacturing
Of the 200 different materials used in the construction of a Formula 1 tire, more than 100 have been created to create an optimal compound, which is based on three main elements, carbon, sulfur and petroleum derivatives. Depending on the characteristics of the circuit, this relationship can vary greatly from one compound to another, while the structure progressively evolves between seasons.
The carcass of the tire is composed of a complex nylon and polyester fabric that constitutes the skeleton of the tires and provides resistance against high aerodynamic loads, longitudinal and lateral forces.
The wheels with grooves existing for a decade (from 1998 to 2008) in addition to supplying an aesthetic aberration caused extra problems to the structure since the changes of direction are more severe with the grooves since the rubber in contact with the parts between grooves tended to deform more than normal.
The dimensions of the tires are limited by the maximum measures dictated by the regulations, however they are often designed to be smaller than the maximum limit for aerodynamic reasons. It must be taken into account that a few millimeters more in the width of the tire can cause the gain or loss of several tenths of a second, especially on high-speed lines.
Efficient Use of Rubbers
While the slicks are designed to work with an optimal temperature around 100ºC , the intermediate compound has a working window between 40ºC and 100ºC depending on the water in the asphalt. On the contrary, extreme rain tires operate efficiently between 30ºC and 50ºC . All the heat created by friction with the surface should be distributed between the various zones of the tires to avoid understeer in case of overheating of the front tires or oversteer in the rear.
Tire pressure is also key as a low pressure allows a greater contact surface with the asphalt but a small difference of just 0.2 kg / cm2 can ruin the performance of the entire car.
As a result, pressure ranges are being watched more closely than ever, both by the FIA and Pirelli. In order to prevent the least possible variation in the pressure of the tires due to changes in temperature, they are filled with a special mixture of gases. To avoid problems, the FIA restricted these gases to air, nitrogen -usually the richest of the three- and carbon dioxide or, introduced through a specific valve while another is used for the exit of the same.
Evolution of Modern Tires
- In 1977 Michelin introduced radial tires when Renault made its entry into Formula 1 with the RS01. The following year, Ferrari would also race with Michelin radials after having had an unofficial test agreement with the French brand since 1969.
- In 1978 the first victory with radial tires was achieved when Carlos Reutemann beat a Ferrari 312T2 in the second round of the championship (Brazilian GP).
- Jody Schekter was the first world champion driver on radial tires in 1979 in a Ferrari 312T4 in the first Ferrari with ground effect.
- In the early 1980s, all tire suppliers adopted radial tires due to the better contact surface with the asphalt while working with tighter angles that made it more difficult to drive to the limit.
- In 1983 Goodyear introduced the first radial rain tire at the Monaco Grand Prix with the unidirectional crocodile skin tread to improve wet traction.
- Goodyear introduced the first radial tires in Formula 1 in 1984.
- In 1985 the use of tire warmers began, very beneficial in the first laps outside the pits, since without heating the tires would take two laps to warm up to minimum working temperature.
- In 1998 the grooves on the tires returned after being eliminated in 1971. The rear tires had four grooves while the front ones only three.
- In 1999 the front tires had four grooves as well. The regulation change led to Goodyear’s exit out of Formula 1 as they were unwilling to increase their investment in the discipline. The introduction of the grooves sparked a host of complaints from drivers including 1996 world champion Damon Hill and 1997 Jacques Villeneuve. Both complained that instead of increasing safety, the effect was the opposite due to the impossibility of stopping the car and the decrease in traction grip. These statements made the Canadian have to apologize to the FIA for ‘inappropriate conduct’.
- In 2007, unlike in previous seasons, all cars had to wear both compounds during the race. To make a difference, Bridgestone came up with the idea of painting one of the grooves in white from the softer compound or extreme rain tires (to differentiate it from the intermediate).
- In 2009 came the return of slicks to Formula 1 after the FIA introduced further restrictions in the aerodynamic field to control the speed cornering rather than limit the tire performance.
- In the 2016 season, a new compound was introduced, the ultra-soft as well as new rules such as the use of three different compounds in each Grand Prix instead of two as was allowed until now.
Tires for Our Cars
As in almost all facets and areas of F1, the evolution of tires and tires in the highest competition has influenced and pushed the acquisition of new technologies in tires that use street machinery (trucks, vans, cars and motorcycles ).
As you can see, for example, in Tirendo today there are a wide variety of tires with different characteristics, depending on the season, size and purpose of use – it is not the same to use the car to go. to work every day, that to compete in a circuit, obviously – exist today. And many of its design, strength and safety features we owe, once again, to the engineers and manufacturers of Formula 1 tires.