Wire wheels, having been used exclusively on bicycles, naturally were adopted as standard by the builders of the early types of automobile. But as the automobile soon increased greatly in weight and as its builders believed that the best results could be attained by wheels of large diameter, wire wheels were found to be lacking in strength and were discarded in favor of wood wheels of the artillery type, which at that time were being imported from France. When a few years later, wire wheels again appeared on some of the English models, the prejudice against them still remained and it was not until about 1914 that they began to find favor in the industry. Drivers of racing cars, however, continued to use wire wheels because they obviated the flywheel effect and lent themselves to quicker braking and accelerating.
Attention first was given to increasing the strength of the spokes, then to their shape, so that, whereas the spokes used in the first tests could withstand only about 6000 shocks, those now in use can resist upward of 1,500,000 shocks before breaking. These results have been obtained from the 25-deg. taper, bung-head type, made of 0.205-in. wire, swaged by gradually reducing the center of the spoke to 0.148 in. in diameter and then increasing it to its original size at the threaded end. The tests that the spokes must undergo are intended to duplicate the various lateral stresses and impacts received in service.
The sudden demand of 5 or 6 years ago caused the double or two-spoke lacing and other discarded and inferior makes to be marketed, and trouble again appeared, but the difficulty has been obviated by the triple-spoke wheels now in use. In addition to greater strength and ability to resist impacts, the advantages of wire wheels are said to include quick changeability and greater tire mileage, due to the resilience of the wheels, which assists in absorbing road shocks, and to the radiating by the spokes of the heat generated by the friction of the tires on the road. The method of driving also has been improved by the use of a corrugated taper drive that is described.
