Tires are one of the most complex and important components on a vehicle. Not only do they support the weight of the vehicle they are mounted on, they also provide traction, handling, and ride comfort. Tires must meet the needs of the individual purchasing them, and must also conform to strict governmental guidelines and vehicle performance requirements. The technology that goes into tire construction incorporates chemistry, physics, and engineering to provide a product that is safe, reliable, efficient, long-lasting and comfortable. Significant testing and research goes into the manufacturing of tires to ensure they are safe.
Most modern-day passenger and light truck tires are constructed with radial ply technology. Radial tires have belt plies with steel and/or a mix of other cord material laid out diagonally beneath the tread of the tire to reinforce and stabilize the tread as it contacts the road. The sidewall has body cords that run across the tire nearly perpendicular to the beads, providing sidewall flexibility.
Tire construction is a mix of layers consisting of differing complex materials. Many raw materials are combined to produce rubber compounds to meet specific characteristics. Depending on where in the tire and what function the rubber will be required to perform determines the rubber compound that will be used. Rubber is the main material used to make tires, but there are several other materials used as well. These materials are combined with the other rubber compounds to form the different components that create a functioning tire.
Body plies serve as the structural foundation of the tire, providing the strength to contain the tire air pressure and carry the load. These are typically made of polyester, rayon, or nylon cords within a layer of rubber. Most tires have one or two body plies.
The tire bead bundles, most commonly strands of wire, secure the tire to the wheel.
The bead filler is composed of rubber compound placed over the bead bundle that can be used between the body plies that wrap around the bead. Bead filler can be used to tune ride and handling characteristics.
Belts made of steel provide stability to the tread of the tire, which affects wear, handling, and traction.
The innerliner is part of the tire that retains the air pressure.
The sidewall is composed of rubber compounds that cover the body plies on the side of the tire and provides abrasion, scuff, and weathering resistance.
The tread is the portion of the tire that provides the grip and abrasion resistance contributing to traction and tread wear. The tread pattern is formed onto the tread. The tread is constructed from different rubber compounds.