Definition of Radial Tyre

In modern engineering, the radial – or belted – tyre has completely replaced the cross-ply tyre. The cords in a radial tyre casing run in the same direction as the car is travelling. Viewed from the side, the cords run radially – giving the tyre its name.

The weakness of this arrangement is that is that the cords cannot sufficiently absorb lateral forces when cornering or circumferential forces when accelerating. To compensate for this, the cords must be supported or complemented by other structural elements such as steel belts etc.

Diagram above shows a typical radial carcass construction. You can see that the cords of the carcass run at 90 degrees to the perpendicular.