“Radial” describes a pneumatic-tyre structure in which the ply cords extend to the beads and are laid substantially at 900 to the centreline of the tread, the carcass being stabilized by an essentially inextensible circumferential belt.

“Bias belted” describes a pneumatic-tyre structure of diagonal (bias-ply) type in which the carcass is stabilized by a belt, comprising two or more layers of substantially inextensible cord material laid at alternate angles close to those of the carcass.