|Aspect Ratio||Section height/section width x 100 - ratio between tire height and width|
opposite sides of a tire's tread pattern are not identical.
distance from the mounting surface of the wheel, which contacts the hub,
to the back rim flange. It is sometimes referred to as the backspacing
or backside measurement.
even distribution of weight on a mounted wheel and tire.
passenger type tire which has two rubberized plies of cords which are
crossed over one another at an angle (on a bias) plus two reinforced
belts which encircle the tires under the tread.
|Block Tread Design||A tire tread pattern made of raised rubber compound segments.|
|Bolt Circle||Sometimes referred to as bolt pattern: The number of lug holes on the diameter of the imaginary circle that each lug hole is centered on.|
|Carcass||The portion of a tire that is the foundation for the tread, belts, bead and sidewall.|
structure of tire cords locked around wire beads.
general term referring to the chemical formula for the tread material.
|Criss-Cross Torquing||The recommended sequential tightening of the lug nuts in a pattern across from one another to help ensure even tightening.|
|Grooves||Circumferential channels between and the tread ribs of a tire.|
situation where the center bore of the wheel is made to match up with
the diameter of the automobile hubs; the wheel is then balanced by the
center hold rather that the lug holes.
|Hydroplaning||Loss of traction at high speeds caused by a wedge of water that lifts a tire off the road surface.|
maximum weight that the tire is designed to carry; dictated by the
tire's construction. Metric passenger type tires are offered with a
Standard Load Rating (up to 35 psi), or Extra Load Rating (up to 41 psi).
LT Metric (truck type) tires are offered with ply ratings of C (8 ply),
D (8 ply), and (10 ply) and at various inflation pressures up to 80 psi.
|Low Profile||A term describing a tire with a low relative aspect ratio or series classification (short sidewall, wide tread).|
condition where the wheel's mounting surface is closer to the inside of
the wheel; when the mounting surface is inboard the wheel's centerline.
|Nominal Rim Diameter||Diameter of rim seat supporting the tire bead. Examples: 13', 15" and 16.5".|
positive or negative distance from the wheel's centerline to the
mounting surface of the wheel.
diameter of the inflated tire without any load.
width in cross-section of the unloaded tire including protruding sides
ribs and decorations.
|Ply||A layer of rubber-coated fabric or wire making up the tire casing.|
condition where the wheel's mounting surface is closer to the street
side of the wheel; when the mounting surface is outboard the wheel's
|Radial Ply Tire||A
type of tire that has one or more rubberized plies of cords running from
bead to bead (at right angles to the tread and parallel to each other),
plus two or more plies of reinforced belts which encircle the tire under
of a tire tread pattern created by grooves that run circumferentially
around the tire.
distance between bead seat to bead seat at beat seat radius.
edge of the wheel's rim that the clip-on weights attach to.
distance between the inside surfaces of the rim flanges.
|Section Height||The distance from rim seat to outer tread surface of an unloaded tire.|
linear distance between the outside sidewalls of an inflated tire
without any load (exclusive of protruding side ribs and decorations).
|Series||A numerical representation of a tire's aspect ratio; for example, 50 series.|
rubber compound segments on the part of the tire tread nearest the
in the tire tread. Small cuts in the surface of the tread to improve
belt material used in radial tires. Its high stiffness provides good
handling and low treadwear.
term representing the portion of a tire measured as its aspect ratio or
|Tread Blocks||Raised rubber compound segments on the outside visible part of a tire.|
|Tread Width||The portion of the tread design that comes in contact with the road.|
total weight of the automobile's components not supported by the
suspension system; wheels and tires are prime examples.
Tire Quality Grade - A government-mandated tire rating system based on a
tire's performance in treadwear durability, traction, and temperature
resistance. UTQG ratings are branded on the tire's sidewall.
of angles and sizes of a tire's tread elements that reduce ride noise
condition where the wheel's mounting surface coincides with the
centerline of the wheel.