The tread is the part of the tire that comes in contact with the road surface, consisting of thick rubber or rubber/composite compound formulated to provide an appropriate level of traction and increase the tire’s driving lifespan

Belts and Casing

Belts are calendered sheets consisting of a layer of rubber, a layer of closely spaced steel cords, and a second layer of rubber. The steel cords are oriented radially in radial tire construction, and at opposing angles in bias tire construction. Belts give the tire strength and dent resistance while allowing it to remain flexible.

Belt Edge Cushion

Belt Edge Cushion is approximately 1-inch wide bands covering only the inner and outer edges of the steel belts and absorbs the stress of belt layer. Westlake tires feature a belt edge cushion to help prevent separation of the belt edges, and therefore the tread, caused by the scissoring effect of the belts. (Available for selected sizes and tread patterns only)

Inner Liner

The inner liner is an extruded halobutyl rubber sheet compounded with additives that result in low air permeability. The inner liner assures that the tire will hold high-pressure air inside, without the air gradually diffusing through the rubber structure. The rubber layer generally consists of butyl, synthetic rubber, or polyisoprene type.

Beads Filler (Beads)

Beads are bands of high tensile-strength steel wire encased in a rubber compound. It is made up of various parts including the bead wire, core, rubber and flipper and contacts the rim on the wheel. 

The bead seats tightly against the two rims on the wheel to ensure that a tubeless tire holds air without leakage.


Undertread is a rubber layer provided for use in retreading the tire, compounded for high heat resistance to increase high-speed durability and fuel economy and provides adhesion of tread to the tire carcass.


The sidewall is located between the tire’s shoulder and bead. It prevents air from escaping and keeps the body plies protected and provides a comfortable riding 

experience due to its flexibility during driving. Also, the type of tire, size, structure, tread pattern, manufacturer, brand name, and other detailed information are 

marked on the sidewall.

Rim Cushion

The rim cushion compound is highly resistant to the heat brought by the heavy load or transmitted by the rim so as to extend the tyre life.