Tread, shoulder, sidewall, bead, carcass, belt, inner liner, and other components are structurally connected to complete the scientific structure of a tire.
The inner liner substitutes for the tube in the tire’s interior and consists of rubber layer with low air permeability. The rubber layer generally consists of butyl, synthetic rubber, or polyisoprene type. The main function of the inner liner is to hold high-pressure air inside.
The breaker is a cord layer placed in between the tread and carcass in a bias tire to protect the carcass. It absorbs external shock and prevents splintering or injury to the tread from coming into direct contact with the carcass. At the same time, the breaker prevents the separation of the rubber layer and carcass. The belt is a strong reinforcement layer located in the circumference in between the tread and carcass in radial tires. The belt’s functions are similar to those of the breaker but it also reinforces the strength of the tread by firmly tightening the carcass.
The tread consists of a thick layer of rubber which comes into direct contact with the road surface. It is highly resistant to fracture and shock in order to protect the carcass and belt located in the tire’s interior. Also, rubber with strong anti-inner abrasion features is used to increase the tire’s driving lifespan.
Located between the tread and sidewall, the shoulder is the thickest part in a tire. Because of this, the shoulder is designed to quickly and easily dissipate heat that accumulates inside the tire while driving.
Located between the tire’s shoulder and bead, the sidewall protects the carcass on the inside 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.
The carcass is the framework of the tire, the most important part. The carcass refers to all layers made up of tire cord. It absorbs the tire’s internal air pressure, weight and shock.
The bead wraps around the end of the cord and fixes the tire to the rim. It is made up of various parts including the bead wire, core, rubber and flipper. In general, the rim is slightly tightened so in the case of sudden reduction of air pressure while driving, the tire will not become unfastened from the rim.