MotoGP tyres in 2021: learn about their characteristics

Michelin has been the official supplier of tyres for the MotoGP category since 2016.

Since it took on the responsibility of supplying the MotoGP grid with tyres, the French brand has developed a new set of tyres every year thanks to the experience and knowledge acquired in every race from the previous season. They optimise the compounds used, analysing the performance and aiming to strike a perfect balance between durability and grip, while offering different options so teams can decide which best suits their bike and the rider’s riding style.

Racing tyres

Michelin produces two types of MotoGP tyres. Slick tyres, which are used in dry conditions, and rain tires, which are used exclusively when there is water on the track. Within these two types of tyres, riders can choose from three compounds for dry races—soft, medium, and hard—and two for races with rain—soft and medium.

But choosing the tyres is not only a question of whether the race will have dry or wet conditions. For example, the temperature differences between GPs vary enormously, so they must be much more precise when choosing the compound to use. There can be races with air temperatures of about 15°C or twice as high. This doesn’t only affect riders and the machines, but also the tyres. In fact, they have to deal with much more aggressive and variable temperatures on the tracks, sometimes touching asphalt at more than 60°C. That is why Michelin develops a different range of compounds for each GP. And it explains that the soft compounds for the French GP, for example, are very different from the soft tyres used in the Malaysian GP.

Also, since tracks have different numbers of left and right turns, or have areas that cause unusual wear, Michelin makes asymmetrical tires, producing the rubber with different compounds on one side and the other.

MotoGP tyres

For each race, Michelin transports hundreds of tyres specifically designed for that route and the most common temperatures there depending on the date when the GP is held. Each rider is given 22 soft, medium, and hard dry tires, of which 10 are for the front and 12 for the rear.

With the limits established by the organisers, the riders and their mechanics, always with support from a Michelin specialist assigned to each team, must select a maximum of five tyres of each front compound, while for the rear tyres, the selection must be for a maximum of six soft, five medium, and four hard tyres. It is important to underline that the riders who ride in Q1 and move on to Q2 will receive an additional set of the compound they prefer.

For rain tyres, 13 tyres are provided per rider, six front and seven rear tyres. The choice of compounds—between soft and medium—will be the team’s decision.
When four out of five classification and free sessions are in the rain, each rider is provided with an additional set of rain tyres. Additionally, if the two classification sessions are in wet conditions, another set will be provided.

During pre-season and the MotoGP tests, the teams also have a limited number of tyres at their disposal. Michelin provides 120 tyres per rider for the entire year, which can also be used by each team’s test riders. These tyres have the same specifications as the ones that are used in competition and standardised for that season. However, Michelin can supply teams with newly developed tyres to do tests, in which case they would not count in each rider’s annual limit.

Michelin is responsible for putting the tyres on the rims at each Grand Prix. All the tyres are distributed randomly between teams, and each one has a personalised code that can be read by the specialists for maximum traceability of the tyre.

Tyre temperature and pressure

Each tyre is designed to provide top performance and durability within specific temperature and pressure parameters. It is therefore fundamental to analyse this data. It is common to see Michelin specialists taking temperature measurements of the tyres and the track, both when leaving and entering the garage.

The ideal pressure for MotoGP tyres is about 2 bars for the front tyre and 1.8 for the rear tyre. This pressure is created with dry air so that the internal pressure is not altered when the tyre’s temperature increases. Additionally, all the wheels have pressure sensors to keep the pressure from being incorrect and affecting performance.

Michelin has also set the temperature a tyre should be heated to before use. The mechanics must put out heaters for at least an hour in the box to reach a temperature of 90°C before going out to the track. On some occasions, it is even recommended to extend this time to up to two hours. The tyres’ ideal performance and operating temperature on the track is about 100°C for the front end, while in the rear it can go above 120°C. It is very important to do it this way, because if the tyres are cold, they cannot reach their full grip potential and the motorbike will begin to slide. When this happens, as the professionals explain, there can be a situation known as graining, when the tyre’s rubber moves as small balls to each side of the tyre, and it loses considerable performance.

The tyres can also overheat due to excess aggressiveness or a high temperature on the track. They also lose grip in these cases, easily sliding on the asphalt and potentially causing bubbles in the rubber, an effect known as blistering.

What punishments are a MotoGP tyre put through?

Tyres are the motorbike’s only point of contact with the ground. And this means that all the force generated by the engine, the brakes, the weight transfer, and the rider’s movement are transmitted to the asphalt through its minimal contact surface. And we’re talking about a contact point equivalent to a bit more then a €2 coin. Riders must be able to use all their racing potential through this small area.

To get an idea of the work tyres are put through, we can simply consider some data: when accelerating straight ahead, the rear tyre withstands more than 2200 Newtons of force (224 kg); for a hard brake of up to 1.5 g, the front tyre exceeds 2500 Newtons (254 kg); and on turns, the lateral forces exceed 2000 Newtons (203 kg).

And while they withstand these forces, tyres must always maintain their shape, without any type of deformation. That is why pressure is so important and studied so thoroughly by Michelin. All of this to prevent accidents and provide riders with the possibility to achieve perfect racing performance.