Do We Really Need Run Flat Tyres?

A tire (American English) or tyre (British English)[1] is a ring-shaped vehicle component that covers the wheel's rim to protect it and enable better vehicle performance. Most tires, such as those for automobiles and bicycles, provide traction between the vehicle and the road while providing a flexible cushion that absorbs shock.

The materials of modern pneumatic tires are synthetic rubber, natural rubber, fabric and wire, along with carbon black and other chemical compounds. They consist of a tread and a body. The tread provides traction while the body provides containment for a quantity ofcompressed air. Before rubber was developed, the first versions of tires were simply bands of metal fitted around wooden wheels to prevent wear and tear. Early rubber tires were solid (not pneumatic). Today, the majority of tires are pneumatic inflatable structures, 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, including cars, bicycles, motorcycles, buses, trucks, heavy equipment, andaircraft. Metal tires are still used on locomotives and railcars, and solid rubber (or other polymer) tires are still used in various non-automotive applications, such as some casters, carts, lawnmowers, and wheelbarrows.

Historically, the spelling was "tire" and is of French origin, which comes from the word tirer, to pull. The reason for this naming is that originally "tire" referred to iron hoops or thick wires bound to carriage wheels. In French blacksmithing the word for a drawn iron rod is a tirer, or pull.[citation needed] The same word was often used for any metal drawing or rolling process. In an article in the London Magazine/Intelligencer of 1853 "The Utility of Broad Wheels," the author explains that the common practice was to bend two rods, called "tires", into hoops and bind them to the wheel, but it is preferable to use an iron band, called a "broad wheel" rather than the rods, because as the rods wear they bite into the wheel. Another early mention of a tire in English is in The Scots Magazine, Volume 15 By James Boswell (1753).

Another etymology of "tire" is provided by Online Etymology Dictionary, essentially that the word is a short form of "attire," and that a wheel with a tire is a dressed wheel.[2] Some other etymologists may share this view.

The spelling tyre does not appear until the 1840s when the English began shrink fitting railway car wheels with malleable iron. Nevertheless, traditional publishers continued usingtire. The Times newspaper in Britain was still using tire as late as 1905.[3] The spelling tyre, however, began to be commonly used in the 19th century for pneumatic tires in the UK. The 1911 edition of the Encyclopædia Britannica states that "[t]he spelling 'tyre' is not now accepted by the best English authorities, and is unrecognized in the US",[4] whileFowler's Modern English Usage of 1926 says that "there is nothing to be said for 'tyre', which is etymologically wrong, as well as needlessly divergent from our own [sc. British] older & the present American usage".[5] However, over the course of the 20th century tyre became established as the standard British spelling.