The head of the stud resembles a bolt head and is wider than the hole in the hub or flange. A knurled area on the rear section of the stud cuts into the hub or axle metal to keep the stud from loosening. Most wheel studs are threaded bolts or studs pressed into the hub or flange. On almost all cars and trucks, the hub or axle flange contains the wheel studs. Almost all radial tires have one or two belts, which reduce tread squirming,Īn important factor in wheel and tire design is the way the rim is mounted to the hub or axle flange. In a bias tire, the cords cross the centerline on a bias, or a slant. In a radial tire, the cords in the plies cross the centerline of the tire at a right angle to the tread. radial tyre constructionĪll modern tires are radial tires. The belts are installed directly under the tread and can be made of the same materials as the plies. Tire cords can be made of various fabric materials, including nylon, rayon, polyester, aramid, Kevlar, or fiberglass. The plies are layers of tire cord that form the general shape of the tire. The internal parts of the tires are composed of plies and belts. The tread and sidewalls are a blend of natural rubber and a synthetic rubber called neoprene. The sidewalls form the support for the treads. Tread designs vary depending on the tire’s application. The external parts of the tire are the tread and the sidewalls. As traction devices, they transmit engine power, as well as braking and turning efforts, to the road. In their role as cushioning devices, they can be considered part of the suspension system. Tires perform two jobs: they cushion shocks and provide traction.