The French Brothers Andre and Edouard Michelin pioneered the pneumatic tires for automobiles. In 1895, they took part in the Paris–Bordeaux car race. Though they did not win the race it kindled the interest of the public, which probably was their main interest. This helped them to become the leaders in pneumatic tire manufacturers in Europe. Legislations were brought out to prevent the use of solid tires on highways as they were hard on the roads. The basic structure of a pneumatic tire is a tube containing the pressurized air as the core and an outer casing made of fabric strengthened with rubberized fiber cords embedded in the rubber wall. This structure remained unchanged for about the next half a century. The rubberized cords ran in a diagonally running in alternating fashion. These cord layers are called ‘plys’ run diagonally in opposite directions the tires came to be known as bias–ply tires.
Michelin introduced the steel belted radial tires in 1948. The steel cords of the ply run at 90o to the wheel rim (against the 55o of the conventional tires) and runs around the circumference of the tire. These radial tires have the advantages of lesser rolling resistance, longer tread life and better steering characteristics and lesser air pressure against the harder drive and 45% more expense in manufacture. In the normal radial tires rayon, polyester or nylon cords are used in the place of steel fabric. It is generally recommended not to use radial tires in cars designed for bias–ply tires as the requirements of the suspension system are different. The American tire companies and automakers were reluctant to buy into the radial technology as they feared the additional investment for making tire and modifying the suspension system would be prohibitive. They took to it only after two decades after the radial tires almost became the standard fitment in Europe and elsewhere.
Tire technology underwent another revolutionary change when in the 1970s, Pirelli ushered in the high performance, low profile radials. The latest in technology which is really revolutionary is the tubeless tire introduced in 1955 by BFGoodrich. There were a few attempts in England and South Africa fell on the wayside due to technical difficulties in manufacture. They have special continuous integral molded ribs into the bead of the tire so as to seals with the flanges of the rim when inflated. These tires are much safer and rides are smoother.