Tyre Business

Tires, or tyres (in American and British English, respectively), are ring-shaped parts, either pneumatic or solid (including rubber, metals and plastic composites), that fit around wheels to protect them and enhance their function. Pneumatic tires are used on many types of vehicles, such as bicycles, motorcycles, cars, trucks, earthmovers, and aircraft. Tires enable better vehicle performance by providing traction, braking, steering, and load support. Tires form a flexible cushion between the vehicle and the road, which smooths out shock and makes for a comfortable ride.

Tire is an older spelling than tyre, but both were used in the 15th and 16th centuries for a metal tire; tire became the settled spelling in the 17th century. In the UK, tyre was revived in the 19th century for pneumatic tyres, possibly because it was used in some patent documents, though many continued to use tire for the iron variety. The Times newspaper was still using tire as late as 1905.

The first practical pneumatic tire was made by the Scot, John Boyd Dunlop, in 1887 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). Tires are mounted to wheels that bolt to the hub. The beads of the tire are held on the wheel's rim largely by the internal tire force from the air pressure. Automotive wheels are typically made from pressed and welded steel, or a composite of lightweight metal alloys, such as aluminum or magnesium. These alloy wheels may be either cast or forged.

The speed rating denotes the maximum speed at which a tire is designed to be operated. For passenger vehicles these ratings range from 99 mph (160 km/h) to 186 mph (300 km/h). For a table of speed ratings, see tire code. Replacing a tire on a vehicle with one with a lower speed rating than originally specified by the vehicle manufacturer will often render the insurance invalid.