Bridgestone Medium and Light Truck Tire Data Book - Sullivan Tire ...

Effective January 2010
B. Radial and Bias Tire Construction
General Technical Information
Radial
Radial tire body ply cords are placed straight across
the tire from bead to bead. In addition, radial tires
have belt plies, which run circumferentially around
the tires, under the tread. They constrict the radial ply
cords and stabilize the tread area.
Bias/Diagonal tires have multiple layers of plies
with the cords in adjacent plies running in alternate
diagonal directions from bead to bead. The tires
may also have narrow plies under the tread, called
breakers, with cords that lie in approximately the
same direction as the body ply cords.
Bias/Diagonal
The type of construction can be determined by
looking at the size designation molded on the tire’s
sidewall. Radial truck tire sizes have an “R” in the
size designation while bias/diagonal truck tire sizes
have a hyphen in the size description. For example
a 10.00R20 tire is a radial, while a 10.00-20 tire is
a non-radial.
In addition, ALL radial tires have the word “RADIAL”
molded onto the sidewall. All radial truck tires also
use an “R” in the size designation, e.g., 285/75R24.5.
Medium Truck Light Truck General Technical Load/Inflation Technical Bulletins
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