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STERLING CHAINLESS

CRANK BRACKET.

In keeping apace with the times, the Sterling Cycle Works of Chicago has produced a novel chainless bicycle of the bevel gear type. In its construction are incorporated ideas which are departures from the chainless models that have already appeared. In the Sterling model the main driving-gear wheel is located at the centre of the crank axle. The small pinion on the forward end of the driving shaft meshes on the right side of the driving wheel. That necessitates the near pinion to engage the teeth on rear hub, back of the axle instead of in front of it, as in some other forms of chainless wheels. This permits the use of the entire lower right rear tube as a container for the connecting shaft, instead of building a frame work for the support of the gears.

The rear wheel may be taken out by removing the step nut and unscrewing the rear axle. The two rear gears are made interchangeable, giving the rider the advantage of seventy-two or seventy-eight geared wheel, as may be desired, with one set of gears. This will be the standard equipment, but another option will be offered by which the rider can have a combination of sixty-four and eighty-eight, if he prefers.

STERLING CHAINLESS

CONNECTING SHAFT.

These special features of the Sterling chainless construction are shown in the accompanying illustrations. The rear fork on the gear side has a boss in which the axle is screwed. The opposite fork end has a circular opening larger than the cross section of the axle and a short slot for inserting the axle. A threaded sleeve fills the circular opening, which is also threaded, abutting against the outside face of the fork end with a shoulder. A lock-nut fits upon the inner projecting portion of the sleeve. In assembling, the wheel is first mounted on the axle; the latter is then screwed into the fork end on the gear side by applying a wrench on the hexagonal portion of the axle projecting beyond the hub on the opposite side. When the gears mesh properly and the lock-nut has been placed on the left side end of the axle, the threaded sleeve is placed in position and the lock-nut is tightened.

The lines of mesh along the teeth of bevel-gears or radial gears, as they are more properly called, always point to a common centre when the gears are in proper engagement. The common centre in the front row gears of a chainless bicycle is at a point in the axis of the crank shaft; but if the two front pinions were interchanged they would cease to have a common apex, and could not be made to co-operate. With the driving shaft at right angles with the crank shaft and the rear axle, the pinions in front as well as in the rear could be made interchangeable only at a pitch of forty-five degrees, which would make the interchangeability of no value. With the driving shaft at another angle with the rear axle, as in all chainless bicycles, it is possible to so proportion the two rear pinions that the mesh lines point to the same centre whether the smaller pinion is on the hub or on the driving shaft. The possibility is limited to two sets of interchangeable gears for any given angle of the driving shaft, which has been taken advantage of by the Sterling Company.

The Sterling Chainless will be made in two models; one for men and a drop frame design for women. Each lists at $125.