Car-tyre construction explained Car tyres are a complex assembly of materials with very different properties.
The following are some of the key elements:
1. Tread The tread rubber compound determines how well the tyre grips on dry roads. In the wet, the best car tyres disperse water using the grooves of the tread, maintaining contact with the road and preventing aquaplaning - where the tyre rides on top of the water, rather than passing through it - which increases the likelihood of a loss of control.
2. Steel belt Rubber-wrapped bundles of steel wire give structural rigidity to the tyre and hold the tread flat to maintain good contact with the road.
3. Sidewalls These combine with the air in the tyre to carry the car’s load. Lower, stiffer sidewalls (as found on low-profile tyres) help the tyre retain its shape better when cornering. This improves handling, but can also make the car's ride less comfortable. The outside of the sidewall is where you will find the tyre size and specification markings, as explained below.
4. Bead wires These are ultra-strong steel wires with extreme resistance to stretching. They hold the tyre onto the rim, even at very high speeds and when cornering.