Harper's Round Table, March 24, 1896

by Various

SECTION OF BALL-BEARING.

Perhaps the most important thing to be considered is the care of the bearings. In the advanced stage which bicycle construction has reached to-day there are a large number of ball-bearings in a machine—in fact, there are balls wherever there is friction, however light. These bearings should have careful adjustment. Perhaps a glance at the sketch of a wheel bearing will make the construction clearer. Of course the bearings of different makes of wheels vary, but the principle is the same in all. The little steel balls are the only medium by which the weight on the bearing is transmitted between the rim and the cone (hub and axle). To have the bearing work properly and with least possible friction, the cone must not be screwed in so tightly as to jam the balls in the rim, or the wheel will run hard; at the same time it must not be unscrewed so as to allow too much play of the balls, or the wheel will "wobble." Most bearings have a flattening on the projection of the cone, between the hub of the wheel and the fork, that can be caught by a wrench, enabling the cones to be tightened or loosened by screwing this one only. Some have a thumb-screw in place of the device mentioned, and other makes adjust the cones by screwing the axle.

In the adjustment of a wheel's bearings, whether front or rear, a good test to use against too tight a cone is to raise the wheel clear of the ground, and, turning it so that the valve of the tire is on top or nearly so, see if the weight of the valve will cause the wheel to rotate so that the valve will describe an arc, like a pendulum, each swing gradually diminishing in length. If the cone is properly adjusted, the valve should swing back and forth for some time. Of course the rear wheel will not swing as long as the front, the valve having to impart motion to the sprocket and pedals. If the cones are too loose, by gripping the wheel by the rim you will be able to slide it back and forth on the axle. The most important bearings in the whole wheel are those of the crank-axle. Here the whole strain of the propelling power comes. The adjustment of these cones is on the same principle as those of the wheels; the same test may be used as for the rear wheel. The two bearings in the steering-head may be adjusted by screwing the cone of the top one, and, of course, the wheel may be made hard steering or easy, to suit the taste of the rider. This is not a matter of material importance. The adjustment of the pedal bearings is not of so great importance, but it should be seen that they run evenly and quietly, as it is at this point that the propelling force is applied. This is usually accomplished by tightening or loosening the outside cone, which may be gotten at by removing the dust-cap.

Perhaps it would be as well to speak here about the quite frequent mishaps of a broken ball in the bearings. As soon as one is found broken, waste no time in removing it; a ball less will do no harm; but if the wheel is ridden with a broken one, it will soon cut the cone and rim all to pieces.

A word about oiling. Do not go to the excess of either too little or too much oil. In the first case the cones and rim will wear more quickly and the bearings run hard; and in the latter, the oil will gum, causing hard running, or, if it does not do this, it will ooze out of the joint, and, collecting the dust, will become gritty and mar it. The amount and frequency of the oiling, of course, depend on the use of the bicycle. For a wheel moderately used, a fair oiling once a week I should deem amply sufficient. Most of the bearings have openings in which to apply the oil, and the oil should not be applied at any other place than this. In the case of the head-bearings, unscrewing the cone of the upper one will expose it, and will permit the head to be raised so as to expose the one on the crown for oiling. The pedals may be lubricated by removing the dust-cap and applying the oil on the outside bearing, tilting the machine so as it will run down to the inside one.

PARTS OF THE WHEEL.
A. Crank-axle. B. Front Sprocket. C. Crank. D. Barrel. E. Pedal. F. Head. G. Upper Cone. H. Lower Cone. I. Handle-bars. J. Grips or Handles. K. Front Hub and Axle. L. Handle-bar Clamp. M. Saddle. N. Saddle-post. O. Saddle-post Clamp. P. Rear Sprocket. Q. Rear Hub and Axle. R. Chain. S. Rear Fork. T. Tire. U. Rim. V. Valve. W. Front Forks. X. Crown.

To have the bearings in "tip-top" condition, they should be cleaned every month or six weeks. In cleaning them the cone should be taken out, carefully wiped, the balls put in kerosene oil to remove all possible grit, and the rim wiped clean of all remains of previous oilings. The easiest ones to get at are those of the front wheel and pedals. In the former case, all that is necessary is to undo the nuts and spring the wheel out of the fork, unscrewing the movable cone, and taking out the axle. In the pedals, remove the dust-caps and the outside cone, and slip the pedal off. The rear wheel is a little more troublesome, the chain having to be removed from the rear sprocket before the wheel can be taken out. To remove the chain, unscrew the small screw-bolt that holds two of the links together. The bearings in the head will also be a little troublesome, having to remove the handle-bars and top cone, and take out the front fork. The only remaining bearings to be spoken of—those of the crank-axle—are in some respects the most important to have clean, and at the same time the most difficult to get at, as it is necessary to take off the cranks before the axle can be removed or the bearings exposed. After the cranks are removed, the rest is usually an easy matter.