Slick tyre

A racing slick (also known as a "slick tire") is a type of tire that has a smooth tread used mostly in auto racing. The first production "slick tire" was developed by M&H Tires in the early 1950s for use in drag racing. By eliminating any grooves cut into the tread, such tires provide the largest possible contact patch to the road, and maximize traction for any given tire dimension. Slick tires are used on road or oval track racing, where steering and braking require maximum traction from each wheel, but are typically used on only the driven (powered) wheels in drag racing, where the only concern is maximum traction to put power to the ground.

Slick tires are not suitable for use on common road vehicles, which must be able to operate in all weather conditions. They are used in auto racing where competitors can choose different tires based on the weather conditions and can often change tires during a race. Slick tires provide far more traction than grooved tires on dry roads, due to their greater contact area but typically have far less traction than grooved tires under wet conditions. Wet roads severely diminish the traction because of aquaplaning due to water trapped between the tire contact area and the road surface. Grooved tires are designed to remove water from the contact area through the grooves, thereby maintaining traction even in wet conditions.

Since there is no tread pattern, slick tire tread does not deform much under load. The reduced deformation allows the tire to be constructed of softer compounds without excessive overheating and blistering. The softer rubber gives greater adhesion to the road surface, but it also has a lower treadwear rating; i.e. it wears out much more quickly than the harder rubber tires used for driving on the streets. It is not uncommon for drivers in some auto sports to wear out multiple sets of tires during a single day's driving.

In Formula One, slick tires were not used from the 1998 to 2008 seasons. Dry weather tires with mandatory circumferential grooves intended to reduce total grip and reduce cornering speeds were used, and were still often referred to as "slicks" as the grooves were not intended to disperse water and could not be used effectively in wet conditions. Slick tires were reintroduced from the 2009 season.

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