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This is an rudimentary diagram of a radial belted tire to illustrate the tire's basic construction.The advantages of a radial tire are due, in part, to the way the tire is constructed. Coated steel cables run from bead to bead perpendicular to the circumferential center line of the tire. These are shown in the diagram as radial plies. Steel belts are then laid over the radial plies under the tread of the tire. This forms a two-part construction in which the sidewalls are a separate unit from the tread structure. - The strength of the multi-layers of steel belts make the tread resistant to punctures. The two-part construction of the tire structure allows the sidewalls to flex independently from the tread. This allows the tread to stay in contact with the road surface even while the sidewalls flex under a load or while cornering. This greatly reduces the chance of foreign objects puncturing the sidewalls since the sidewall doesn't "roll over" to present itself to the road surface.
- The same construction elements that make the radial tire puncture resistant also give it better traction than bias ply tires. The radial's tread stays in contact with the road surface even under a load. A bias ply tire will distort its tread under a load and so reduces the amount of tread area that is in contact with the road surface.
- The steel cables in radial tires act as a heat sink to dissipate heat. This keeps the tire running at a cooler temperature than an equivalent-sized bias tire. The plies of a bias tire hold heat and so are more prone to blowouts when the tire heats up during sustained highway driving.
- The radial tire--due to its two-part construction--offers a quieter, smoother ride than the bias tire. It is also more fuel efficient since it offers less resistance to the road surface. This is a term referred to as "rolling resistance." Overall, radial tires have longer life compared with bias tires under similar workloads and environments.
