Tires are installed on the vehicle together with disc wheels. Vehicles ride on pneumatic tires filled with pressurized air. Tires are the only vehicle components that come into direct contact with the road surface. If the tire air pressure is improper, this can cause abnormal wear and lower the driving performance. Tires perform the following functions:
The tires support the overall weight of the vehicle.
The tires directly contact the road surface and therefore transmit the vehicle’s driving and braking forces to the road, thus controlling starting, acceleration, deceleration, stopping, and turning.
The tires attenuate (reduce) shock caused by irregularities in the road surface.
(1) Tires The types of tires are tubed tires and tubeless tires. Also, there are radial tires and bias tires, both of which comprise the following parts.
<2>Belt (rigid breaker)/Breaker
<3>Carcass (cross plies)
<5>Bead wire There are also other types, such as compact spare tires (temporary tire types) used for punctures and other emergencies, and run-flat tires on which you can drive a certain distance even with a puncture.
(2)Tire size The size, performance, and the construction of the tire are indicated on the sidewall of a tire. The diagram on the left shows the names of the sizes of the various areas of a tire.
1. Types of tread patterns
A wide variety of patterns are molded into the tread both to help drain away water, and to cope with various factors dictated by the conditions of the road surface and the type of the vehicle being used.
The rib pattern consists of several parallel zigzag grooves that run along the circumference of the tire. This pattern is best suited for traveling on paved surfaces at high speeds and is used for a wide variety of automobiles, from passenger cars to buses and trucks.
The rib pattern minimizes the resistance of the tire to rolling.
Greater resistance to side-slipping provides good vehicle controllability.
Tire noise is reduced.
Traction is somewhat inferior to that of tires with the lug pattern.
(2) Lug pattern
The grooves in the lug pattern run at roughly right angles to the tire circumference. Frequently used on construction machinery and truck tires, this tread pattern is suited for driving on unpaved roads.
The lug pattern provides good traction.
Tire rolling resistance is somewhat high.
Resistance to side-slipping is smaller.
Tread in the lug area is susceptible to uneven wearing.