-Wheels are made of either stamped or pressed steel
discs riveted or welded into a circular shape or are
die-cast or forged aluminum or magnesium rims.
-The primary purpose of tires is to provide traction.
They are also designed to carry the weight of the vehicle,
to withstand side thrust over varying speeds
and conditions, to transfer braking and driving
torque to the road, and to absorb much of the rock
shock from surface irregularities.
-Pneumatic tires are of two types: those that use inner
tubes and those that do not. The latter are called
tubeless tires and are about the only type used on
passenger cars today.
-There are three types of tire construction in use today:
bias ply, belted bias ply, and radial ply.
-Tires are rated by their profile, ratio, size, and load
range.
-Tire construction affects both dimensions and ride
characteristics, creating differences that can seriously
affect vehicle handling.
- An ideal tire is one that wears little, holds the road
well to provide sure handling and braking, and provides
a cushion from road shock. should also
provide maximum on dry roads, wet roads, and
snow and ice, and operate quietly at any speed.
-There are basically three categories of tread pattems:
directional, nondirectional, and symmetric and asymmetric.
A directional tire is mounted so that it revolves
in a particular direction and will perform
well only when it is rotating in that direction. A
nondirectional tire has the same handling qualities in
either direction of rotation. A symmetric tire has the
same tread pattern on both sides of the tire. An asymmetrical
tire has a tread design that is different from
one side to the other.