The thickness, or widths of the tires also minimizes the impact and distribute the jars while running, so that with these advantages a small wheel has been found to be more practical than a large one.
Resiliency.—Most wheels are now made with wooden spokes, secured by means of a pair of metal-flanged hub plates, bolted together so as to clamp the radiating spokes, but wire wheels are now coming more into favor, whereas cast or pressed solid steel wheels are used on some heavy trucks.
CHAPTER III
TIRES, TUBES, AND RIMS
Tires.—Three kinds of tires are now used, namely: Solid, cushion, and pneumatic. These forms all use rubber, or some compound with the qualities and characteristics of rubber, so as to afford a good tractive surface, as well as resiliency.
Fig. 11. Solid Tire.
The solid tires are used on heavy trucks, where weight and not speed must be provided for.
Cushion tires are sometimes employed on cars and trucks of medium weight.
Pneumatic tires, in which air is used, are universally used in automobiles for all other purposes.
