CHAIN ADJUSTMENTS.
Some form of adjuster will always be necessary to adjust the chain on a chain driven bicycle. On the early models of the safety type of bicycles made in this country the adjustment was produced by a swinging crank bracket. The crank bracket was not an integral part of the frame, but was bolted to it and was held in position by a set screw and lock-nut. Somewhat later an improved form, which by the usual form of reversion has now come into use again, consisted in making the crank bracket an integral part of the frame and fitting an eccentric adjustment inside of it. The Remington Company varied this somewhat by making the rear forks a detachable part of the frame and having them bolted through and locked by a threaded lock-nut and bolt at the crank hanger, and they thus produced their adjustment by shifting the rear forks out backward or drawing them forward. Since that time the makers of the Remington have always used the rear fork-end adjustment, but this season they have a new feature. The crank-hanger ball pocket is eccentric and turns in the bracket either forward or backward when the set bolts are loosened. The whole arrangement is a very simple one and prevents the liability of the rear wheel getting out of alignment.
The makers of the Iroquois also use a 3-inch eccentric hanger. The rear wheel is always centred by this method, and is provided with two sprockets, so as readily to allow a change of gear.
On the Defender is shown an eccentric crank-hanger, on which neither the wheel, nuts or bearings are disturbed to make the adjustment.
The Shirk bicycles have a new rear fork and chain adjustment, the advantage of which is that the rear wheel can be removed without disconnecting the chain. The sides of the rear fork ends are machined with teeth, which fit into the teeth of the washer, and by simply unscrewing nut and withdrawing the axle bolt the wheel drops out of frame. Absolute equality of adjustment on both sides is obtained, as the wrench is only used to loosen the axle nut, and as the outward opening the rear fork ends is done away with, strength and rigidity is thus added to this end of the frame.
The makers of the Northampton made a new chain adjuster consisting of a small round steel plate on the outside of the rear forks, with scroll cut on the inside which follows steel lug on the forks, making it easy to adjust chain to any tension and set the wheel true in the frame rapidly.
The chain adjuster used on the Globe is of very neat and simple construction. A threaded adjuster, having an open hook end is pivoted to the upper part of the rear fork end, and is operated as follows: Loosen the axle nuts and turn the thumb screw either way, as the case may be, until the chain has the right tension and then tighten the axle nuts again. To take the rear wheel out, loosen the axle nuts and swing the hooks off the axle. To replace the wheel slip the hooks back over the axle, tighten the nuts and the whole adjustment is complete.
On the Relay is shown a patent chain-adjusting device which enables the rider by simply loosening the nuts on either side of the rear wheel to remove the rear wheel without taking the chain apart. The fork ends are of cold rolled steel, corrugated, with the washer corrugated to correspond, allowing accurate adjustment of the chain.
VICTOR SPROCKET.
On the model 4 [Humber] is shown a rear fork chain adjuster, which is similar in construction to the chain adjusters in use on the Humbers made in England. The rear fork ends instead of being carried horizontal as before now slant upward at an oblique angle, and the backstays instead of being brazed to the rear forks as heretofore are separate and are carried backward or forward, as the case may be, with the rear axle to tighten or loosen the chain, the object of this change in construction being to cause the backstays to help carry with the rear forks the weight of the rider on the axle.
The [Wolff-American] patent eccentric chain adjuster is almost too well known to need describing. Still it is such a radical departure, and withal such a good one, that it will bear describing here again. A square groove or spline is cut on the sides of the rear axle, running about an inch from the end. A pair of eccentric disks, having a tongue or key to fit this groove, are slipped on the axle, thus becoming, as it were, a part of the rear axle. They are then placed and held in the frame by semi-circular braces, which are a part of the frame. The chain is adjusted from one side, the eccentrics acting together. By loosening one nut on each side the eccentrics are free to move either way. This completes the operation, and, it is needless to say, one need not worry about getting the rear wheel out of line or readjusting the bearings, because with this eccentric adjuster neither is disturbed. They use the same method of adjustment on the rear wheel of their tandems, but the front chain on the tandems is adjusted with an eccentric at the front crank-hanger, same as most of the other makers use in tandem construction. Nearly all the makers who make tandems adjust their rear wheel, however, with their regular form of chain adjuster as used on their singles, a variation of this, however, being to adjust both chains at the crank-hanger brackets with an eccentric adjustment.
Another variation in chain adjustments on tandems consists of bolting the crank bracket to the frame so that by moving the crank bracket forward or backward the chain can be adjusted to the proper tension. The makers of the juvenile “Elfin” not only use this form of construction on their juvenile tandems, but also on their single models, and have in addition to that a method of reversing the bracket, so that it can be either bolted on top or underneath the rear forks which permits an adjustability of two inches between the seat posts and pedals, by which an Elfin may be made to last a growing child for several seasons.
HUMBER CHAIN ADJUSTER.
CHAPTER VII.
HUBS, SPOKES AND RIMS.
The wheels of the 1898 bicycle do not present any very remarkable or striking novelties in construction. The old style of slender cylinder hub with broad flanges has, however, disappeared, and the tubular or barrel hub, with or without flanges, is the only one in use. But before surveying the state of the art for this season let us take a look backward and see what led up to the present types. At the Crystal Palace, London, England, was exhibited in 1889 a bicycle that was built by Gavin Dalzell, a Scotchman, some time previous to 1846. This was described as “being wonderfully strong, especially in the wheels,” these seeming to have stood the ravages of time and rough usage much better than the framework. The rear wheel, or driver, was of wood shod with iron, about 40 inches in diameter, and had twelve spokes, each about one inch in diameter. The front wheel was of similar construction, but only about 30 inches in diameter. The wooden velocipede of 1866 usually had wooden spokes and flat iron tires, and about that time a very crude high wheel was built in England by S. Madison, and this in 1868 was improved upon by Edward Cooper. In 1869 the bicycle called the “Phantom” was put upon the market. It had wooden rims with rubber tires nailed on. On the inside of the rim were staples, through which the wires were passed and screwed at the centre of the wheel. It was really the first practical suspension wheel ever built, its one fault being its liability to get out of order and the inability of the mechanics of that time to true it up again. James Starley brought out a bicycle a little later called the “Ariel,” which had “lever tension” wheels and was popular. It had double wire spokes and steel rims, and at the axle of each wheel was placed a lever bar.
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.