history

The earliest tires were bands of iron (later steel), placed on wooden wheels, used on carts and wagons. The tire would be heated in a forge fire, placed over the wheel and quenched, causing the metal to contract and fit tightly on the wheel. A skilled craftsman, known as a wheelwright, did this work. The tension of the metal band served the purpose of holding or "tying" the wooden spokes of the wheel together, hence the term "tire." In addition to tying the spokes together, the tire also provided a wear-resistant surface to the perimeter of the wheel. As wheels changed over time, the term "tire" continued to be used for the outer band even when it no longer served the purpose of tying the spokes together.
The first practical pneumatic tire was made by the Scot John Boyd Dunlop for his son's bicycle, in an effort to prevent the headaches his son had while riding on rough roads (Dunlop's patent was later declared invalid because of prior art by fellow Scot Robert William Thomson). The pneumatic tire also has the more important effect of vastly reducing rolling resistance compared to a solid tire. Because the internal air pressure acts in all directions, a pneumatic tire is able to "absorb" bumps in the road as it rolls over them without experiencing a reaction force opposite to the direction of travel, as is the case with a solid (or foam-filled) tire. The difference between the rolling resistance of a pneumatic and solid tire is easily felt when propelling wheelchairs or baby buggies fitted with either type so long as the terrain has a significant roughness in relation to the wheel diameter.
Pneumatic tires are made of a flexible elastomer material such as rubber with reinforcing materials such as fabric and wire. Tire companies were first started in the early 20th century, and grew in tandem with the auto industry. Today over 1 billion tires are produced annually, in over 400 tire factories, with the three top tire makers commanding a 60% global market share.