TIRE TERMINOLOGY

1. Cold Inflation Pressure the measure of air pressure of a tire that is not warm from driving (less than 1 mile or standing for at least 3 hours)

2. Alignment refers to the correct angle settings of suspension components - the 3 alignment settings are caster, camber and toe.

2.1 - Camber the angle of the centerline of a tire and wheel relative to completely vertical.

2.2 Caster the angle between the vehicle's steering pivot axis and completely vertical.

2.3 Toe the difference between the distance between the front left & right tire and the distance between the

rear left & right tire. Toe-In means that the front of the tires are closer together than the rear. Toe-Out

means that the rear of the tires are closer together than the front.

3. Balance equal distribution of the weight of a tire and wheel. If a tire & wheel is not balanced it can lead to

vibrations or uneven wear. For balancing, weights are attached to the wheel to compensate for uneven

weight distribution.

3.1Wheel Weights weights attached to a wheel to balance a tire & wheel. The weights can be on the inside or outside of the wheel and can be clipped, taped or self-adhered to the wheel.

TIRE NOMENCLATURE

Section Width the distance between the sidewalls at their widest point of an inflated tire not under load.

Aspect Ratio the relationship between a tire's section height and its section width. It is calculated by dividing the

section height by the section width. When the section height is half of the section width, the aspect

ration is 50. In a tire size description, it would be the 50 in P195/50R15. It is also called the tire's profile

or the series.

Load Index a number used to represent the maximum weight a tire can support. The index number corresponds to the actual load carrying capacity. Truck tires use a different system incorporating letter codes to

establish a Ply Rating.

Speed Rating a letter that identifies a tire's high speed durability. A tire's capabilities are tested at preset speeds and the results of these tests determine the tire's speed rating. Speed Ratings include: Q, S, T, U, H, V, Z,W, Y

TIRE SPECIFICATIONS

Tread Blocks individual sections of the tread separated by lateral grooves

Tread Depth the distance from the top of the tread to the grooves in a tire. This measurement is taken at the

centerline of a tire and is measured in thiry-secondths of an inch.

Tread Pattern the arrangment of grooves, blocks, sipes and channels on the tread.

Tread Shaving shaving some of the tread from a tire for optimal performance and durability in racing applications.

Tread Wear also called the tread life, it is the measure of how long a tire lasts. It is measured in miles or kilometers.

Tread Wear Indicators narrow rubber bars built into the tread grooves that define the tire's legal wear out point. Also called

the wear bars, they are even with the tread when 2/32" of tread is left and then the tires are ready to

be replaced. >More Info

Treadwidth the width of a tire tread, normally measured in millimeters. In 195/50R15 the treadwidth is 195mm.

Ribs rubber sections of the tread that run around the circumference of the tire

Grooves the space between two tread ribs of a tire

Sipes small slits in a tire's tread that help push water away from the crown of the tire for improved wet

traction. They also provide biting edges for ice and snow traction.

Shoulder the outer edge of the tire tread where it meets the sidewall

Bead the part of the tire in contact with the wheel flange. It is made of high tensile steel wires shaped to fit

the rim and hold the tire on the wheel. The steel wires are wrapped in woven fabric and held in place

by the plies.

Bead Seat the edge of the rim that creates a seal between the tire bead and the wheel

Belted Bias Tires tires constructed similar to bias tires, but with reinforcing belts between the casing plies and the tread.

Belts rubber coated cords located between the plies and the tread. They help reinforce the tread, as well as

help the tire keep its shape against such forces as: tire inflation pressure, centrifugal force, cornering

and braking. These cords are made from such materials as steel, fiberglass, radon, nylon, polyester or

other material.

Ply layers of cord fabric that give a tire its strength. They are situated between the tire tread and the

innerliner, and they run from bead to bead. These cords are rubber coated.

Cord strands of nylon, rayon, polyester, steel or fiberglass that make up the plies & belts of the tire. The

strength of a tire & its load carrying capacity is determined by the strength of the cords.

Crown the center section of the tire's tread

Curb Guard extra rubber running around the sidewall of a tire. It is there to protect the side of the tire and the wheel face from any damage that may come as a result of hitting a curb.

Sidewall the side portion of a tire between the tread and the bead.

Chafer abrasion resistant rubber coated material to help prevent the tire's beads from rim damage and

chafing.