measurement from the back of the bolt pad to the back edge
of the rim; used to calculate offset and determine where the
back of the bolt pad is located in relation to the rim
width, sometimes referred to as rear spacing.
uniform mass distribution of a tire and wheel assembly about
its axis of rotation.
form in which solid rubber is shipped to tire manufacturers.
ball-and-socket connection that lets a steering knuckle move
in several directions at the same time.
area of the mounted tire which seats against the wheel.
rubber extrusion in the bead area of a tire; used to permit
a smooth contour of casing plies around the bead and to the
lower sidewall. Also used in enlarged form to stiffen the
lower sidewall of a tire.
position where the tire rests and seals on the inside of the
assembly of fabrics and/or wire used to reinforce a tire's
tread area. In radial tires, it also constrains the outside
diameter against inflation pressure and centrifugal force.
Wedge or Insert
extrusion of rubber placed under the edges of a belt; used
in radial tires to improve durability.
bias tire with additional reinforcing belt's between the
casing plies and the tread.
tire built with two or more casing plies which cross each
other in the crown at an angle of 30 or 45 degrees to the
rubber bag used inside a tire during the molding and curing
process; contains hot water steam which presses the inside
of the tire into the mold.
tire with a cosmetic or minor uniformity imperfection but
whose safety and performance are unaffected.
of a tire tread pattern created by lateral (side-to-side)
structure except for tread and sidewall rubber.
referred to as the bolt pattern; the diameter of an
imaginary circle drawn through the center of each lug hole.
Torque applied by a brake to a tire/wheel assembly which
slows or stops the vehicle.
point at which tire cornering traction is lost.
steering effect resulting from toe or camber changes as the
suspension moves up and down.