Dateline 3500 B.C.--Today
man invented the greatest invention ever seen, THE WHEEL!
Thousands of years
later, the wheel has come a long way. For one thing it is no longer made
of wood and it is guaranteed that the ride is much smoother. What hasn't
changed is the fact it is still one of man's greatest inventions. Could
you even imagine where we would be today without it?
The
early wheel was very simple...a solid curved piece of wood, then leather
was eventually added to soften the ride, as time progressed it became
solid rubber which led to today's tire--the pneumatic, or air inflated,
radial tire.
The first wheels made
of metal or wood were very durable but did not provide a very comfortable
ride. The nearest thing to the first tire was a metal hoop. There were
many individuals that made contributions in creating the tire as we think
of it today.
Vulcanization and
Charles Goodyear
Rubber was not always
as useful as it is today. Early rubber did not hold shape; it would be
sticky in hot weather and become inflexible in the cold.
In 1839 Charles Goodyear
was credited with the discovery of the vulcanization process. Vulcanization
is the process of heating rubber with sulfur. This transforms sticky raw
rubber to firm pliable material which makes rubber a perfect material
for tires.
The story of Charles
Goodyear is a sad one, although he dedicated his entire life to making
rubber a better form he would never profit from all his work. Charles
Goodyear died bankrupt.
Forty years later
a rubber company would honor his hard work by using his name for their
new tire company.
Solid Rubber Tires
Soon, after the discovery
of vulcanization tires were made out of solid rubber. These tires were
strong, absorbed shocks and resisted cuts and abrasions. Although they
were a vast improvement, these tires were very heavy and did not provide
a smooth ride.
Today there are still
types of tires made of solid rubber
Pneumatic Tires
The pneumatic rubber
tire uses rubber and enclosed air to reduce vibration and improve traction.
Robert W. Thomson, a Scottish engineer, first patented the air filled
tire. Unfortunately the idea was too early for its time and was not a
commercial success.
In 1888 John Boyd
Dunlop of Belfast, Ireland became the second inventor of the pneumatic
tire. Dunlop claimed to have no knowledge of Thomsons earlier invention.
The second time around
the pneumatic tire caught the publics attention. The timing was perfect
because bicycles were becoming extremely popular and the lighter tire
provided a much better ride.
Bias Ply Tires
For the next fifty
years vehicle tires were made up of an inner tube that contained compressed
air and an outer casing. This casing protected the inner tube and provided
the tire with traction.
Layers called plys
reinforced the casing. The plys were made of rubberized fabric cords that
were embedded in the rubber. These tires were known as bias-ply tires.
They were named bias ply because the cords in a single ply run diagonally
from the beads on one inner rim to the beads on the other. However, the
orientation of the cords is reversed from ply to ply so that the cords
crisscross each other.
Today you can still
find bias-ply tires as authentic equipment for antique and collector cars,
as well as for certain type of off-the-road tractor tires.
Radial Tires
Michelin invented radial tires in 1948 and they were first introduced in Europe that year. Radial tires are
so named because the ply cords radiate at a 90 degree angle from the wheel
rim, and the casing is strengthened by a belt of steel fabric that runs
around the circumference of the tire.
Radial tire ply cords
are made of nylon, rayon, or polyester. The advantages of radial tires
include longer tread life, better steering and less rolling resistance,
which increases gas mileage. On the other hand, radials have a harder
riding quality, and are about twice as expensive to make.
Copyright 2007 Wilson Tire & Auto Service. All Rights Reserved.