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The earliest tires were made by skilled artisans called wheelwrights who used bands of metal, such as iron or (later) steel, to reinforce wooden wheels for wagons and carts. They heated metal in a forge fire, and then formed it over a wooden wheel. The wheel was then thrust into cool water, causing the metal to contract and fit tightly. The added metal provided a wear-resistant surface to the perimeter of the wheel.
A Scotsman named John Boyd Dunlop developed the first practical air-filled (pneumatic) tire for his son's bicycle. Unfortunately, due to previous designs by fellow Scot Robert William Thomson, Dunlop's patent was later declared invalid.
The pneumatic tire vastly reduced rolling resistance, compared to that of a solid wooden tire. Pneumatic tires are made of a flexible material, such as natural or synthetic rubber, with fabric and wire added as reinforcing elements. Due to the internal air pressure and additional elements, a pneumatic tire absorbs road bumps, and provides a friction bond between the vehicle and the ground.
Tire companies began manufacturing pneumatic tires in the early 20th century and production grew in tandem with the automobile industry. Today, over one billion tires are manufactured annually, in over 400 factories, with the three top tire companies commanding a global market share of 60%.
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