Tire Constructions
They destinguish two main tire constructions: radial construction and bias or crossply construction. Radial tires are believed to be more safe and have a far greater rigidity for deformation. They got widely spread in usage throughout the last 20 years or so.
Tire Components And Their Difference in Bias and Radial Tires
Thread. Consists of specially compounded/vulcanised rubber with unique characteristics ranging from wear resistance, cut resistance, heat resistance, low rolling resistance, or any combination of all. The thread is purposed to transmitting the forces between the rest of the tire and the road.
Same for bias and radial constructions.
Sidewall. Protective rubber coating on the outer sides of the tire. It is made for resisting cutting, scuffing, weather checking, and cracking.
Same for bias and radial constructions.
Chafer. In bias tires protects the bead and body from chafing (wear from rubbing) where the tyre is in contact with the rim. In radial tires acts as a reinforcement. Designed to increase the overall stiffness of the bead area, which in turn restricts deflection and deformation and guarantees the durability of the bead area. It also assists the bead in transforming the torque forces from the rim to the radial ply.
Liner. Integral part of all tubeless pneumatic tires. It covers the inside of the tyre from bead to bead and prevents the air from escaping through the tire.
Same for bias and radial constructions.
Bead. In crossply tires consists of bundles of bronze coated high tensile strength steel wire strands which are insulated with rubber. A crossply tire designed for offroad usage has two or three bundles.
A radial onroad tire usually has only one. The bead is considered the foundation of the tire. It anchors the bead on the rim.
Body.
Tire carcass in crossply tires. It consists of layers of nylon plies. The cord body confines the pressure, which supports the tire load and absorbs shocks encountered during driving. Each cord in each ply is completely surrounded by resilient rubber. These cords run diagonally to the direction of motion and transmit the forces from the tread down to the bead.
Body plies in radial tires are made up of a single layer of steel cord wire. The wire runs from bead to bead laterally to the motion direction (hence the notion “radial plies”). The body ply is a primary component restricting the pressure which ultimately carries the load. The body ply also transmits the forces (torque, torsion) from the belts to the bead and eventually to the rim.
Breakers.
In bias/crossply constructions guarantee protection for the cord body from cutting and increase tread stability. Made of nylon, aralon, or steel wire.
Belts.
In radial constructions belts represent layers of steel cord wires located between the tread and the body ply. Offroad tires can have up to five belts. Road tires have one or two. The steel wire of the belts run diagonally to the direction of motion. Belts increase the rigidity of the tread which increases the cut resistance of the tire. They also transmit the torque forces to the radial ply and restrict tyre growth which prevents cutting, cut growth and cracking.
Comparison of Tire Constructions
| Bias/Crossply | Radial | |
|---|---|---|
| Vehicle Steadiness | Yes | No |
| Cut Resistance: Tread | No | Yes |
| Cut Resistance: Sidewall | Yes | No |
| Repairability | Yes | No |
| Self-Cleaning | Yes | No |
| Traction | No | Yes |
| Heat Resistance | No | Yes |
| Wear Resistance | No | Yes |
| Floatation | No | Yes |
| Fuel Economy | No | Yes |
