V17/Outcome 4

How tyres got their name Thankfully tyres have come a long way since a craftsman, know as a wheelwright, would forge bands of steel to the wooden wheels of wagons and carts! This steel band literally ‘tied’ the spokes of the wheel together and so was called a tyre - and the name just stuck.

RW Thomson invented and patented the Pneumatic Tyre in It was not until the late nineteenth century, 1888, that John Boyd Dunlop invented the Rubber Pneumatic Tyre. In 1890 CK Welsh patented the design of a wheel rim and outer cover with inextensible lip. Michelin’s creation of the radial tyre with its vastly superior grip in 1948 Dunlop did away with the inner tube on car tyres in 1972

It was in 1839 that Charles Goodyear discovered that by adding sulphur to melted latex the much sought-after attributes of elasticity and strength were attainable. This new vulcanised rubber was used initially as ‘cushioning tyres’ for carriages and cycles: 1915 that the Palmer Tyre Company of Detroit pioneered Cord : rubber coated strands of fabric laid over each other crossing the thread direction, (cross-ply) Later strands of steel were added for strength.

Section width Aspect ratio RadialSection width Aspect ratio Radial Rim diameter Load index Speed rating.Rim diameter Load index Speed rating NEXT

Measured in millimetres (mm) The section width is the distance between the walls.

As a percentage (%) of the section width

Cross-ply tyres will have the word cross-ply on them somewhere but not where you will find an “R” on a radial.

Rim diameter in inches (“)

Which company manufactures the largest number of tyres each year? How many different units of measurement are used on tyre labelling? What are run-flat tyres? What is the speed rating for a space-saver wheel?

How is a tyre tread made? What is the purpose of the bead? What should you not do with cross-ply and radial tyres? How many spare wheels should be carried if omni-directional tyres are fitted to a vehicle?