The Modern Bicycle and Its Accessories

by Alex Schwalbach; Julius Wilcox

He next designed one called the “Spider” and for a long while all bicycle wheels were therefore called spider wheels. In 1876 Singer’s “Challenge” appeared in London, which had lock-nut spokes, with a nipple attached. Nipple and lock-nutted spokes long outlasted the construction of that day, and they were certainly very far better than the butt-ended direct spokes used later on.

The first tangent spokes were those made by the Coventry Tangent Company, in England, and placed upon their bicycles and tricycles. A singular fact is that for some years after that, however, tangent spokes almost wholly disappeared, not only in this country, but in England, and, while we were importing English safety bicycles, all of them had direct spokes; but the first American safety bicycle built, the Victor, had tangent spokes, and so had the high wheels previously made by the Victor Company. In England, until two years ago, direct spokes were very largely used.

THE “SUSPENSION” WHEEL.

Here American makers used direct spokes at first, but at present all the American makers without exception use a tangent spoke, and there are indeed very good reasons for the use of the tangent spoke in a suspension wheel, which is a structure radically unlike the ordinary wagon wheel. Any vehicle wheel receives the load of the weight carried directly at its hub, through the axle, and this weight, of course, tends to bear the hub down to the ground. The wagon wheel has stout spokes, as they are planned to sustain the crushing downward strain; this strain is wholly borne by the few spokes at any particular instant below the hub, the rest of them at that instant having no work to do. In order to avoid the weight and clumsiness inevitable if the bicycle wheel were made to carry the load in this way, the load is “suspended,” in effect, instead of being above and upon the spokes. That is, the load applied at the hub is hung from the few spokes which at the instant are directly over the hub; the pull down on these spokes tends to depress the upper part of the rim and thus to flatten down the wheel from a circular to an elliptical shape; but this flattening is resisted by the spokes which are then horizontal, or nearly so, and thus the wheel retains shape. The thin wire spokes, which would instantly double up under a “crushing” strain, resist tremendously the tensile pull. Imagine a thick-spoked wheel with all spokes gone except those in say an eighth of its circle directly underneath the hub and you have the ordinary wheel; then imagine a bicycle wheel with all spokes gone except a few directly above the hub and the few horizontal ones on each side of the hub, and you have the “suspension” wheel illustrating its own principle, it being supposed that the wheel in each case is not moving but simply holding up its load.

CRESCENT HUB.

The wagon wheel is “dished,” that is, the spoke ends at the hub are not quite in the same plane with the rim; the spokes are also often “staggered,” that is, one-half are in one plane at the hub and the rest in another, the object being that the wood may have room to expand and contract somewhat, under changes in moisture, without putting the wheel out of shape. The suspension wheel is also dished, but the dish is a double one, the wheel in section being like two capital V’s, end to end, being somewhat wide at the hub, the spokes being carried from the rim alternately to one side of the hub and the other. The object is to strengthen the wheel laterally, for if it were made all in one plane from top to bottom it might sustain a heavy load in a vertical direction, but would twist into pieces under the first side strain. This explanation may not only give the uninitiated a better idea of bicycle construction but may illustrate the fact that new problems have had to be met and new devices thought out and worked out at every stage of that construction.

CONSTRUCTION AND STRAINS OF HUB AND SPOKES.

The pressure applied on the pedals of the bicycle causes a transverse strain on direct spokes which sometimes causes them to snap at the rim or hub; but spokes which are set at a tangent to the hub receives this strain directly, and in the tangent-spoke wheel, where the spoke is bent or hooked in order to pass through the side of the hub, it is necessary that the very best material and workmanship be used to prevent it from breaking at this point. The tangent-spoked wheel being almost absolutely rigid, is the best hill-climber, for there is no waste of power as in the direct-spoke wheel, the transverse strain on the spokes of which causes a certain amount of “give.” On the first safety bicycles built in this country 30 and 32 inch wheels were used. Afterward we settled down to the use of 28-inch wheels as a standard. There is now, however, a slight tendency to reversion toward using 30-inch wheels. The makers of the [Cleveland wheel] have announced that they will market a bicycle having 30-inch wheels. Probably the only reason for this step lies in the dropped crank-hanger fad; so that, by using larger wheels, they can still maintain the upper tube horizontal, and get the required drop of from three to four inches. Viewed in another aspect, however, it will be found a source of annoyance and expense to the makers and riders as necessitating an extra stock of spokes, rims and tires to fit the same, and where they are not to be had promptly delays will be sure to occur in repairing. The ruling size of wheel is not arbitrary, but has been arrived at as the best net adjustment of all the conditions, and any change to what has been thoroughly tested and abandoned is to be strongly disapproved, unless (which is not the case in this) substantial reasons can be shown.