| Word | Description |
|---|
| Air pressure |
Force exerted by air within tyre, expressed in bar. Note that pressure is not equivalent to force change |
|---|
| Alignment |
The wheel and suspension setting of the factory specification for any given vehicle |
|---|
| All season tyres |
Tyres designed to be used all year round as opposed to dedicated summer or winter tyres |
|---|
| Apex |
A reinforcing rubber component that provides stiffness in the bead area |
|---|
| Aquaplaning |
The process of water building up in front of a moving tyre until it lifts the tyre away from the road causing loss of control |
|---|
| Aspect ratio |
The ratio of the height of the sidewall to the width of the tyre tread expressed as a percentage. For example in 205/55R16, '55' is the aspect ratio. The height of the sidewall is 55% of 205 mm |
|---|
| Assymetrical |
Tyre tread patterns which vary from one side of the tread to another, i.e they are not symmetrical. They must be fitted with the outside sidewall on the outer face of the weel.This is typically indicated on the sidewall. |
|---|
