oped especially with the requirements of the heavier forms of selfpropelled vehicles in mind and is stronger than the form having a lesser number of spokes.

The spokes are similar in construction to those used in bicycle wheels but are much stronger and made of higher grade material

on account of the severe duties they perform. The spoke is provided at the lower end with a button head to keep it from pulling through the hole in the hub when it is tightened by the threaded nipple at the upper end passing through and having a head which bears against the rim. After the spokes of a wire wheel are in place all the nipples are screwed up so that the tension on practically all

the spokes is as nearly the same as it is possible to obtain and have the wheel run true. The method by which the upper end of the spoke is attached to the rim is clearly outlined at Fig. 213-B.

The construction depicted at Fig. 214 is the Rudge-Whitworth wire wheel fitted with the Houk quick detachable rim. The wheel is of English design and is widely used abroad. It is of the triple spoke pattern and is made so it can be removed easily from the inner hub casting in which the bearings are carried. The hub shell to which the spokes are fastened is held in place by means of a substantial locking nut F which keeps the serrations in the hub members firmly together to insure that the two parts B and E will turn as a

unit when the lock nut F is tight

ened. The wheels shown at Fig. Fig. 212.-Typical 215 are an American pattern

Wheel.

known as the McCue, that at A being a front wheel while the form outlined at B is used on a live axle and serves as a traction member.

It is claimed that with wire wheels considerably more elasticity is present than in wooden members and that this type of wheel is much easier on tires. Experiments conducted during the past two or three years have served to establish the belief in some quarters that wire wheels double the life of tires as compared to wooden wheels. The main reason advanced is that wire wheels are extremely light at their peripheries and the reduction of weight at this point overcomes the flywheel effect and heavier blows of the wooden wheel rim when it strikes an obstruction in the roadway. The difference between the effect of shock on the tires of a wooden wheel with a heavy demountable rim at its periphery and the wire wheel with its light

single rim is equal to the difference between a blow struck with a light hammer and one struck with a hammer weighing six or eight pounds. Obviously, as the wheel revolves the force of the tire striking the surface of the road is almost the same as though a blow were being struck against the tire

With the wire wheel the weight is suspended from seventy common points. It is never entirely supported on one spoke in compression as is the case with a wood wheel. When an obstruction is met it is like striking a punching bag between ropes as the shock

Triple and Double

Spoke Construction.

X

A

B

Fig. 213.-Outlining Structural Details of Wire Wheels. A-—Arrangement of Spokes. B-How Spokes are Secured to Rim.

is absorbed by the flexible steel members joining the wheel rim to the hub. With wooden spokes a portion of the shock is absorbed by the wood but a large part of it is transmitted directly to the wheel hub.

Another quality of equal importance is the ability of the wire wheel with the spokes laced tangent to absorb the shock of starting or sudden application of power in the plane in which the wheel rotates. This quality is absent in wood wheel construction.

It is a well known fact that the friction between tire and road generated in driving a car at even a reasonable speed results in quick

and excessive heating of the tire structure. In the wood wheel, which serves in a sense as insulation, there is a very slight ability to quickly dissipate heat. Wire wheels requiring only a thin metallic rim, the spokes serving in a sense as cooling flanges, will dissipate this heat almost as quickly as it is generated. This results in keeping the tire at almost normal temperature even in very warm weather.

The wire wheel properly constructed can be manufactured and kept so nearly true, both laterally and circumferentially,

that it practically eliminates all

A, detachable flange, Houk patent quick detachable rim. B, hub shell, detachable. C, inner hub fixed to bearings.

D. flange against which the shell fits.

E, Serrations-70 or more in number, to hold hub shell from turning on inner hub. Flock nut - holds demountable in place, is self-tightening and is removable with simple spanner wrench or ordinary tools.

wear other than that resulting Fig. 214.-Construction of Rudgefrom the friction of a perfectly

true revolving wheel.

Whitworth Detachable Wire
Wheel.

Q. What are detachable wheels and where are they used?

A. Detachable wheels may be either of the wire wheel pattern or of the artillery construction. In all forms of detachable wheels two hubs are necessary, an inner member which is in permanent assembly with the axle and a removable outer member to which the spokes and rims are attached. In the Rudge-Whitworth construction shown at Fig. 214 the steel shell to which the spokes are laced is readily removable from the inner member or hub casting proper. The object of this construction is to permit the motorist to carry a spare wheel with a fully inflated tire so that in event of puncture or blowout it is possible to remove the entire detachable wheel assembly affected and replace it with the spare member carrying the

fully inflated tire which has been provided for replacement purposes.. All detachable wheels are constructed so that they may be readily removed from the inner hub member and the entire wheel assembly may be replaced much easier and quicker than replacing the ordinary form of tire.

The wheel shown at Fig. 215 is a quick detachable form normally held in place on the tapering hub shell member by a threaded re

Fig. 215.-Typical American Wire Wheels of McCue Design.

tention nut and which is driven by means of a series of pointed driving pins riveted to a flange on the inner hub and passing through suitable openings in the outer hub shell. The construction of front and rear wheels is practically the same, except that the inner hub of the former is intended to revolve on the steering spindle while