This thick layer of rubber provides the interface between the tire and the road.
Wear-resistant rubber is used to protect the carcass and belt against fractures
and impacts and to deliver a long driving life.
Located between the tread and sidewall, the shoulder rubber is the thickest so that
the design must allow for the easy diffusion of heat generated within the tire while
driving.
The part between the shoulder and bead, the flexible sidewall protects the carcass
and enhances the ride. A tire’s type, size, structure, pattern, manufacturing company,
product name and various characters are indicated here.
The bead attaches the tire to the rim and wraps the end of the cord fabric. Comprised
of the bead wire, core, flipper and other parts, the bead is generally designed
to be slightly tight around the rim so that in the case of a sudden drop in inflation
pressure, the tire will not fall off the rim.
As the most important framework of a tire, the entire inner layer of cord fabric
is called the carcass. The carcass acts to support air pressure, vertical load and
absorb shocks.
The breaker is a cord layer placed between the carcass and the tread in order to
protect the carcass of a bias tire. The breaker reduces shocks, prevents rips or
injury of the tread from reaching the carcass directly while also stopping the separation
between the rubber layer and the carcass.
The belt is a strong reinforcement found between the tread and the carcass in a
radial or belted bias tire. It functions much like the breaker but also increases
tread rigidity by tightly winding about the carcass.
The inner liner is made of a layer of rubber that resists air diffusion and replaces
the inner tube within a tire.
Generally made of a synthetic rubber called butyl, or a rubber of the polyisoprene
variety, the inner liner maintains the air inside the tire.