Copyright Goodheart-Willcox Co., Inc. 337 Chapter 16 ∣ Wheels and Tires Tires Competent service methods and the correct choice of tire type and size are essential to the safety of a powersports vehicle. This portion of the chapter explains tire designs, sizes, and markings, as well as repair and replacement procedures. This will prepare technicians to use manufac- turer recommendations when selecting and servicing tires. Tire Design Recent years have seen many advances in tire design. Because some motorcycles are extremely powerful and heavy, better tires are needed to provide proper wear and handling characteristics. There are two types of tires: tube and tubeless, Figure 16-27. The principal difference between the two is how the air is held in the tire. Tube Tires Tube tires use an air-filled tube within the tire’s casing. This means that air in the tire leaks out instantly when a nail or other sharp object penetrates the tire and tube. Tubeless Tires Tubeless tires have a rubber layer (inner liner) glued to the inside of the tire’s casing, which prevents air from filtering through. This acts in place of an inner tube. A tubeless tire also has a special bead area that, together with the special rim, makes a tube unnecessary. The inner liner is sufficient in thickness and does not stretch like a tube. The lack of an inner tube means the tire runs cooler because of the elimi- nation of the friction between the tire and tube. Tubeless tires may indicate that they are tubeless on their sidewalls. See Figure 16-28. Most ATV and UTV tires are tubeless. Wheels for tubeless tires have a snap-in valve stem. The rim mating area in wheels for tubeless tires is different from the rim area in wheels for tube tires. For this reason, it is best to never mix the two types. Types of Tires When selecting a replacement tire in the past, you needed to keep in mind these five considerations: tire construction, size, load and speed ratings, vehicle use, and tread pattern. Today, tires are constructed and sized to fit specific motor- cycles, ATVs, UTVs, and scooters. You will need to check the service manual for the manufacturer’s recommendations. There are three types of motorcycle tires: bias-ply, bias-belted, and radial. See Figure 16-29. Most machines today have a limited number of replacement tire options because of the specific sizes, speed rat- ings, and tire types required by the machines. Tread Tread Tube tire Tubeless tire Sidewall Sidewall Bead Rim line Tube Bead Rim line Inner liner Tube valve Rim valve Honda Motor Co., Ltd. Figure 16-27. The principal differences between tube and tubeless tires. Goodheart-Willcox Publisher Figure 16-28. Sidewall indicates this is a tubeless tire.