A tire is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground. The fundamental materials of modern tires are rubber and fabric along with other compound chemicals. Today, the vast majority of tires are pneumatic, comprising a doughnut-shaped body of cords and wires encased in rubber and generally filled with compressed air to form an inflatable cushion. Pneumatic tires are used on many types of vehicles, such as bicycles, motorcycles, cars, trucks, earthmovers, and aircraft.
What is important in the "Fast/Slow" context is that during years have developed a variety of different tires depending on which vehicles may be assembled, and consequently have different purposes and performance; for example, a tractor tire must be huge and partculary shaped in order to grasp on disconnected grounds, and so is designed for very slow speed:
|A tractor tire is not designed to go fast, but to grasp on different grounds.|
We can clearly see the differences with a racing tire, which is designed for reduce friction with the ground and so make the car run as fast as possible, with its slick shaped:
|A racing tire is designed to go reduce the friction with the ground and as consequence to go fast.|