Copyright Goodheart-Willcox Co., Inc. Motorcycles: Fundamentals, Service, Repair 340 on- and off-road use. Figure 16-34 shows examples of each of these treads. Because there are so many different designs and tread patterns available, it is advisable to fol- low the manufacturer’s suggestions regarding tire size and design, Figure 16-35. Tire Inspection For safety, tire condition should be checked periodically. Visually inspect the tread and sidewall for cuts, cracks, and wear. Uneven tread wear can be caused by incorrect infla- tion pressure or an unbalanced tire. If a road hazard, such as a pothole, is struck, it is important to check the tire, rim, and spokes for possible damage. One of the most important inspections is tire pressure. All tires lose air over time. Check the air pressure in the tires. If the tire pressure is too low t o support the load, it can cause heat due to sidewall bending. Underinflation also causes the cord layers to separate and wear the sides of the tread. Overinflation results in inferior riding comfort. High pressure also causes the tire to skid and the tread to wear at its center. See Figure 16-36. Tire Service Tire service includes inspecting the tire for damage and defects, as well as changing a tire, repairing a flat tire, and balancing a tire and wheel assembly. B C A B C D A aon168/Shutterstock.com Figure 16-34. Motorcycle tires vary in rubber compounds, profile, and tread pattern. A—High-performance road tire suitable for sport riding. B—Universal designs are intended for use on road or in dirt. C—Trial universal designs are also dual purpose, but not as suitable for road use. D—Knobby design is strictly for off-road, dirt riding. Goodheart-Willcox Publisher Figure 16-35. Selection of ATV tires. Proper inflation Underinflation Overinflation Tread contact with road Tread contact with road Tread contact with road Yamaha Motor Corporation U.S.A. Figure 16-36. Effects of tire air pressure on tires.