The main function of the tread rubber isto maintain contact between the tyre and the road surface. The various patterns of tread used make this the mostdistinguishable, but by no means the most important, part ofthe tyre.
Tyre materials may be classi?ed as rubber compounds, cordmaterials and bead wire, and it is worth re?ecting thatalthough their various properties differ considerably theymust work in harmonious physical contact throughout thelife of the tyre.
There are different types of tyre patters.
- Rib Pattern
- Rib Lug Pattern
- Lug Pattern
- Road / Highway Rib Pattern
- Mining Lug Pattern
Tyre Characteristics:
When a vehicle is being driven along the road, the tyres areacted upon by complex and variable system of forces thatarise in the vertical, longitudinal and lateral directions. Themanner in which the tyres react to these forces de?nes theirmain characteristics
- Cushioning
- Rolling Resistance
- Direction ability
- Self-Aligning
Tyre Types:
Cross-ply tyre:
The angle at which the cords of each ply intersect the circumferential centre line of the tyre is usually about 40°. It is chosen to provide the best compromise in the cushioning and directional properties of the tyre.
Radial Ply Tyre:
The radial-ply tyre is therefore relatively free from internal friction because of the non-crisscross pattern.To achieve good cushioning properties, the walls of thistype of tyre are made as ?exible as possible by arranging thecarcass ply cords at right angles. The plycords follow the contour of the tyre from bead to bead.
Run Flat Tyre:
The run-?at tyre is concerned with both safety and mobility. It serves the twofold purpose of maintaining vehiclestability in the event of a sudden de?ation and permittinglimited vehicle operation after the de?ation.