1. OVERVIEW
A radial tire uses a cord angle of 90 degrees. That is, the cord material runs in a radial or direct line from
one bead to the other across the tread. In addition, a radial tire has a belt overwrap under the tread
surface to provide greater structural stability. The belt overwrap of a radial tire distortion while the radial
structure enables high speed driving.
Tire supports the weight of the vehicle, reduces the impact from the road and at the same time,
transmits the power to propel, brake and steer on the road. It also functions to maintain a
vessel of air.
There is wear limit mark on the tire, which protrudes as a strip shape located approximately 1.6 mm from
mark on the shoulder to let the driver find the wear mark easily. To measure the tire groove depth,
measure at any point other than the point which has a wear limit mark.
The tire is worn unevenly according to the driver's driving habit, improper servicing, low tire inflation
pressure, changed tire location, etc.
1) Structure of Tire
Tread
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.
Shoulder
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.
Sidewall
The part between the shoulder and bead, the
flexible sidewall protects the carcass and
structure, pattern, manufacturing company,
product name and various characters are
indicated here. Bead
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.
Carcass
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.
Valve
Belt
Bead core
