Figure 42-3 shows a cutaway view of a typical tubeless
tire. The basic parts are shown. The cord body or
casing consists of layers of rubber-impregnated cords,
called plies, that are bonded into a solid unit. Typically
tires are made of 2,4, or 8 plies; thus, the reference to 2-,
4-, and 8-ply tires.