Tyre Anatomy And Construction Get an inside look at each of the elements that make up a typical tyre. 1. Airtight synthetic rubber liner Most modern tubeless tires are constructed with a virtually impermeable butyl rubber liner. This liner replaces the old inner tubes. Check your tyres' air pressure monthly, as some air loss occurs over time. 2. Carcass ply The carcass ply is comprised of thin textile fiber cables that are bonded into the rubber. These fiber cables are largely responsible for determining the strength of the tyre. 3. Beads The beads are responsible for clamping the tyre firmly against the rim of the wheel. 4. Sidewall In addition to giving the tyre its height, the sidewall protects the tyre against impacts with curbs and other objects. The sidewall also contains all the markings which tell you the important information about the tyre, such as speed rating, load rating, and tyre dimensions. 5. Crown Plies Crown plies provide the rigid base for the tread which allows for good gas mileage. The plies also provide centrifugal and lateral rigidity to the tyre, while also allowing the tyre to flex sufficiently for a comfortable ride. 6. Tread The tread is designed to provide traction in a variety of conditions. Good tread design also resists wear, abrasion, and heat. On the sidewall, you can find branding that identifies the materials and number of layers of each of the different types of materials used to construct the tire. For example, a typical tyre might have the following basic construction material listed