Blistering
Blistering is a type of tire damage in motorsport where bubbles form on the tire surface due to excessive heat, which then burst and cause chunks of rubber to break away, reducing grip and performance.
When a race car's tires get too hot, the rubber compound begins to break down internally. The heat causes the outer layer of rubber to separate from the inner layers of the tire, creating air pockets or bubbles underneath the surface. These bubbles look similar to blisters you might get on your skin from friction or heat, which is how this tire problem got its name.
As the tire continues to rotate and heat up, these blisters eventually burst open. When they pop, they leave behind rough, damaged patches on the tire surface. Small chunks of rubber start peeling away, creating an uneven and compromised contact area between the tire and the track. This damage is visible to the naked eye and can be spotted by teams monitoring their tires during pit stops.
Several factors can cause tire blistering. Aggressive driving that involves a lot of wheel spinning or sliding generates excessive heat. Hot weather and high track temperatures make tires more susceptible to overheating. Incorrect tire pressure settings, particularly when tires are overinflated, can cause the center of the tire to balloon outward and overheat. Even the car's setup, such as suspension stiffness or aerodynamic downforce levels, can contribute to putting extra stress and heat into the tires.
The effects of blistering are serious for race performance and safety. As the tire surface breaks apart, the car loses grip because there's less rubber making proper contact with the track. This makes the car slower through corners and harder to control. Drivers may experience unpredictable handling, with the car sliding more than expected. Braking distances increase because the damaged tires can't grip the road surface as effectively.
In severe cases, blistering can weaken the tire's structural integrity enough to cause a dangerous tire failure or blowout at high speed. This is why teams monitor tire conditions closely throughout a race and may call drivers in for earlier pit stops if they spot signs of blistering developing.
Teams work to prevent blistering through careful tire selection, choosing compounds that match the expected track conditions and temperatures. They constantly monitor and adjust tire pressures to keep them in the optimal range. Engineers may also modify the car's setup to reduce tire stress, and drivers might need to adjust their driving style to be smoother and generate less heat in the tires.
It's important not to confuse blistering with graining, another common tire problem. While blistering happens when tires get too hot, graining typically occurs when tires are too cold and haven't reached their optimal operating temperature. Graining creates small tears and ridges on the tire surface rather than bubbles and missing chunks. Blistering is generally considered the more severe of the two issues.