Tyre

The rubber part of the wheel which contacts the ground. The construction can be bias-ply, bias-belted, or radial. The plies are made of rayon, nylon, and polyester. Belting can be fibreglass, steel, or kevlar. The rest of the tyre is hard rubber.

Cross-section through a tyre and wheel rim.

Aspect Ratio

The ratio of section height to section width multiplied by 100.

Tyre Bead

That portion of the tyre that bears against the rim flange. The bead has a number of turns of steel wire in it to provide great strength.

Tyre Gauge

An instrument for determining the pressure in a tube or tyre.

History

1839 Charles Goodyear invented vulcanized rubber later used for tyres.

1845 Robert William Thompson produced the first pneumatic tyre

1888 John Boyd Dunlop produced the first pneumatic tyre for bicycles

1904 Carbon added producing black tyres.

1904 Goodyear and Firestone started producing cord reinforced tyres

1908 Frank Seiberling: grooved tires with improved road traction

1922 Dunlop: steel cord thread in the tyre bead

1943 Continental: patent for tubeless tyres

1946 Michelin introduced the radial tyre

1947 BFGoodrich introduced the tubeless tyre

See also: Independent Suspension, Rolling Resistance, Tyre Bead, Tyre Tread Pattern, Wheel.