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Bicycle

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BICYCLE, a light vehicle formed of two wheels mounted in single line in a simple frame of steel tubes, which is equipped with handles, pedals attached to cranks and a saddle. The rider sits on the saddle, grasps the handlebars, and turns the cranks with his feet by means of the pedals, thus imparting motion to the rear wheel through a chain driven over toothed rings or sprockets.

After several decades of intensive research, development and improvment, bicycles have become the most numerous class of vehicle on the roads of England, France, Germany, Holland, Italy, Belgium and Denmark, while they are very widely used in North America and elsewhere. The bicycle is easily mastered, and can be ridden with very little effort at ten to twelve miles per hour by any normal person. Being easy to house and carry, inexpensive to purchase and maintain, and simple in construc tion, it is a valuable instrument of self-transport, and it provides pleasant recreation and exercise even while being used for purposes of utility. Cycle-touring is most widely practised in England, but has a large and increasing number of followers in Germany, France and other European countries. Bicycles are also widely used for racing in France, Germany, Belgium, and to a lesser extent in England and the United States (see CYCLING) .

The oldest existing trace of the cult of self-propulsion occurs in a stained-glass picture in a church window at Stoke Poges, Buckinghamshire, England. This depicts a figure seated upon a wheeled instrument and apparently using the feet against the ground to propel itself. That, at any rate, is the interpretation placed upon the picture by all authorities. The next development was a ponderous four-wheeled carriage propelled by a footman, whose unenviable task it was to depress two heavy timber levers alternately, thus turning the rear wheels by a crude rack-and pinion device. This is referred to in contemporary English liter ature from 1769 onwards, and an improved form was exhibited in Paris and actually paraded before the court of Louis XVI.

and Marie Antoinette at Ver sailles in The Hobby-horse, 1816.

Nothing was gained by such con trivances, for the best speed, even with two drivers, was barely equal to walking pace, and there is no further trace of a veloci pede in history until 1816, when an important development occurred in Paris. This was the intro duction of the hobby-horse, a simple device consisting of two wheels and a cross-bar, upon which the rider sat while he pro pelled himself with his feet against the ground. Invented by M. Niepice, a pioneer of photography, the celeripede, as it was called, quickly gained favour. In 1818 it was further improved by Baron de Saverbrun, who is said to have performed some re markable feats of speed upon it; and in the same year it came to London, where many models were made by Dennis Johnson of Long Acre, The price was high and the machine was not within the reach of ordinary folk; thus it became known as the dandy-horse, and was used by the prince regent, among The craze—for such it undoubtedly was—spread to America and lasted for a year or two in the Old and the New World, until the natural crudities of the device killed it, and nothing more is recorded until 1840, when the first real bicycle was made in Scot land by Kirkpatrick MacMillan, of Dumfries. This pioneer took a dandy-horse, added cranks, pedals and driving rods to it, built a comfortable seat, elaborate armrests, handlebars, etc., and rode the machine for many years, once being prosecuted and fined for "furious driving" on the roads. In 1846 Gavin Dalzell improved MacMillan's machine, and the Dalzell became widely known, many specimens being made.

These two men are the real pioneers of the bicycle.

After them no important event in bicycle history took place for nearly 20 years. It was during this period that isolated ex amples of velocipedes were built in remote parts of England and other countries, and most of the apparently baseless claims to have "built the first bicycle" relate to this era.

But hitherto there had been no bicycle with rotary cranks.

That came in 1865, and was the invention of Pierre Lallement, a workman employed by M. Michaux, of 29, Avenue Mon taigne, Paris, an address which is given here in full because it was the first shop at which bicycles were made and sold in an ordinary commercial way. Lallement sold the patent to Michaux and then emigrated to the U.S.A., where he propagated the same idea. Meanwhile Michaux did good business with the velocipede at zoo francs each. At about the same time an extraor dinary wave of interest in velocipedes swept over England, and inventions and freak constructions were numerous. The indus try in England was begun on regular lines by the Coventry Sewing Machine Company, who, in order to fulfil an order placed by their Paris agent for 50o machines of the Michaux type, re constructed their business in 1868 under the name of the Cov entry Machinists' Co. Ltd. Afterwards it became the Swift Cycle Co. Ltd. However, when only a few of the bicycles had been despatched to Paris, the Franco-Prussian war broke out, and this mischance actually established the trade in England, for it com pelled the Coventry Machinists' Co. to find a home market for the remainder of the 500 machines ordered for Paris.

These Michaux-pattern bicycles belong to the class which came to be known as "boneshakers." They had two wheels of nearly equal size (the front being larger), and the driving-cranks and pedals were fitted to the axle of the front wheel. With heavy wooden wheels, thick iron tyres and a massive iron backbone, these machines were extremely heavy, and they vibrated in a terrifying manner over the rough roads. This vibration and weight caused intense fatigue to the rider, but despite this the new vehicle gained in popularity, for it opened up new possibilities.

The Tall "Ordinary..

Then some important improvements came, as more firms began to manufacture boneshakers, and new ideas were brought into the industry. The heavy wooden wheels gave place to lighter ones of metal, with thin wire spokes set at a tangent to the centre. Solid rubber tyres were cemented to the rims, and the increased speed potentialities were utilized by en larging the front or driven wheel, so that a higher ratio of gearing was employed or, in other words, a greater distance was travelled with each revolution of the cranks. This tendency continued, and the front wheels grew from 3oin. to 40, 48, 52, 6o and even 64in. in diameter, while the rear wheel shrank to 12in. or less. This was the type known as the "ordinary," and it remained in vogue for 20 years, during which time bicycling became a firmly established pastime in England, America, France and other coun tries. Ball-bearings were introduced in 1877.

The "ordinary" bicycle naturally gave a great advantage to tall men, who could sit a higher wheel, and thus command a larger gear and travel at a faster speed for the same pedalling rate. If lacking in inches, however, the shorter men were not without brains, and several schemes were devised to place them on an equality with their taller brethren. One of these was the "geared ordinary," in which the cranks and pedals were mounted considerably below the front axle, to which power was transmitted by a chain running over sprock ets. Short riders began to turn in increasing numbers, however, to the tricycle, or three-wheeled cycle, which, while the "ordinary" bicycle remained current, gained a popularity out of all proportion to its vogue in more modern times.

The "Safety."-The

"safety," or low bicycle familiar to mod erns, was made possible by geared-up transmission ; that is, the pedals and cranks drove a large sprocket, from which mo tion was imparted by a chain to a smaller sprocket on the hub of the rear or driven wheel. Thus, although the rear wheel was much smaller than the driven wheel of an "ordinary," the drive could be geared up so that the bicycle's speed in relation to the pedalling strokes was as fast or faster than that of an "ordinary." Curiously enough, the custom has survived of describing a bicycle's "gear" by comparing it with an "ordinary" ; for example, a bicycle geared to 65 travels as far, with one revolution of the cranks, as would an "ordinary" bicycle with a 65-in. front wheel.

First invented by H. J. Lawson in. 1876, the "safety" rear driven bicycle was first marketed in a practicable form by Messrs. Starley and Sutton, of the Rover Company, in i885, and from that time the "ordinary" was doomed, although it lingered until the early 'nineties, and was brought to a really excellent state of precision and lightness (the best racing "ordinaries" weighing only I 9 lb.) . The following figures tell their own story, however. They represent the percentage of the different types at the two great cycle exhibitions in England during the critical years : 1889. 1891. 1893.

Ordinary . . . . . . 11.5

• • Rear-driven safety S3.6 86.7 84.6 Single tricycle 22.1 The greatest revolution in bicycle history was the introduction of the pneumatic rubber tyre in 1889 by John Boyd Dunlop, of Belfast. Although received with scepticism at first, it was quickly appreciated at its true worth, riders finding that it gave an ' enormous increase of comfort and speed. In an attempt to stem its advance, makers introduced a cushion-tyre which enjoyed a brief vogue, but soon the air-tyre carried all before it. The fol lowing percentages at the English exhibitions are significant : 1891 189o. 1891. (later) . 1892. 1893. 1894.

Solid .

. . . 98.6 29.1 16.6 4'0 3.1 0.4 Cushion . . . •o6 54•2 Pneumatic . . 1.2 65'5 The combination of "safety" bicycle and pneumatic tyre placed the bicycle on an unassailable foundation, and since that date its use has rapidly spread. The "safety" bicycle of 1 893 was the modern bicycle in general outline, although there have been many important alterations in detail, as will be shown. Free wheels, which enabled the bicycle to coast or overrun the driving mechan ism, were introduced in 1894, and variable gears in 1899.

The bicycle-making industry in the United States was started in 1877 when Col. Albert A. Pope of Boston, Mass., organized the Pope Mfg. Company. The new industry went through about the same changes in models and types, as in England-the Ordi nary, the Geared Ordinary, a lever propelled machine called the "Star" with a large driving wheel at the rear and a small steer ing wheel in front, solid and cushion tyre safety, and in 1890 finally the pneumatic tyre safety. The industry had a period of great prosperity in 1892-94, when it established a sound ,export business. This was assisted by the fact that when, just after wards, a similar boom began in England, the demand exceeded the supply, and American machines were eagerly snapped up. The English boom was a very important epoch in cycle history. Bicycling became fashionable among the wealthy classes, prices soared and many companies were floated and refloated. Later came the inevitable slump, after which the English factories were reorganized and learnt to produce a reliable bicycle at a very mod erate price.

The Modern Bicycle.-In

its modern form the bicycle is a remarkable piece of engineering, for it carries a load up to ten times its own weight, and is pro pelled over all kinds of surfaces with very few mishaps. The two wheels run in perfect alignment, as also do the two transmission sprockets, while all bearings are truly parallel to each other and to the direction of travel. Bicy cles weigh from 15 to 35 lb., the lightest being suitable only for racing on specially-prepared tracks. The constructional details are as follows : Frame.-This gains its great strength from its triangulated design, by which there is no unsupported beam except the front forks. If the latter were braced or supported, they would impart all road shocks direct to the rider, unless a satisfactory spring ing arrangement was evolved-a difficult problem. As it is, the forks are curved so that they spring slightly, while the section of weldless steel tubing used is round, oval or D-shaped (with the flat side facing inwards) . It is usual to draw the tubing in a thickness which tapers from 21 gauge at the hub end to 18 gauge at the top. This prevents the concentration of strain at the top end. The fork crown (at the top of the forks) is fixed to the steering column, which turns freely in two ball bearings in the head tube, and in which is set the handlebar. The slope or steer ing angle is the cause of a bicycle running naturally in a straight line, because any movement of the wheel out of the straight tends to raise the bicycle slightly; therefore the weight of bicycle and rider discourages any such deflection of the front wheel except when directed by the rider, and a truly-made bicycle will run in a straight line so long as it is upright, except when the front wheel is forced aside by stones, etc. From this point of view even more steering angle, or "rake," would be permissible, but the de sirability of curving the front forks, and also the need for avoid ing breakage, keeps the angle within moderate limits.

The steering column is a very important part, and ought to be of 13-gauge thickness at the bottom end, and it is usual to make the to taper to 16 at the top end, where threads are cut to accommodate the head ball bearing cup, the locking-rings, etc. Breakages usually result from the negligence of makers who, finding the column too long for the particular bicycle they • are making, shorten it by cutting away the valuable thickened part at the bottom, to avoid the trouble of making new threads which would be necessitated were they to shorten the column at the top. For steering columns and forks a steel with a minimum carbon content of .32% is recommended.

Main Frame Tubes.-In

the better quality bicycles these are butted or thickened at each end, where the gauge is usually 19, as against 22 in the centre. Mild steel, i.e., steel with a carbon content of .35%, is generally used, and it has been found that the double-butted tubing is much stronger than a plain tubing of 20 gauge. This is because "fatigue" is better distributed in a tapering gauge tube, and also because the ends of the tubes have to be filled in order to "clean-up" after brazing, so that the extra thickness of the butted tubes is an insurance against undue weak ening by over-filing. The frame tubes are joined by "lugs" or sockets, which are made in various angles as necessary. Lugs were originally made of malleable iron castings, but light steel pressings have been found to save weight and to serve the same purpose. In brazing, the parts are heated to a dull red, and this work must be done very carefully to ensure, first, that sufficient brass is run into the joints, and secondly, that the tubes are not burned and weakened through over-heating.

Instead of brazing, acetylene welding can be employed, and lugs dispensed with. Welding leaves a smooth surface and is stronger, but in the event of breakage the whole frame must be renewed, whereas any single tube may be replaced in a brazed frame. Welding is rare in England, but commonly employed in France and Belgium.

Many improvements have been made in the method of housing the rear wheel in the frame, and on all racing bicycles, and many non-racing (called "roadster") bicycles, it is possible to remove or replace the rear wheel in a few seconds.

Wheels.

These consist of rims, spokes and hub. Rims may be of steel, aluminium alloy, wood or wood steel armoured. The first named is the most commonly used in England; whereas, in France and Germany wood and steel are both in wide use, while America, Belgium and Holland favour wood or wood steel armoured more than steel.

In the United States the wood steel armoured rim is used in a large majority of the bicycles manufactured. This rim has all the resiliency of a wood rim and having a thin covering or armour of sheet steel, is thereby protected against the action of the weather, splitting or warping.

Steel rims are made in 18 or 2o gauge and are rolled over at the edges to provide shoulders for the stiff wired edges of the tyres. Wood rims have similar shoulders where they are intended for this class of tyre, but in England these rims are more com monly used for the tubular racing tyre. Sizes of rims, throughout most bicycle-using countries, are expressed by the overall size of the tyre which fits the rim in question; thus, a rim described in England as 26 by I-lin. is actually only about 23in. in diame ter, because the size of 26in. refers to the diameter of the tyre when it is properly in position upon that rim. Aluminium alloy rims are non-rusting, and lighter than steel, but bulk must be added to provide the necessary strength.

Spokes are of steel wire, threaded and adjustable at the point where they pass through holes in the rims, while at the other end they are bent at right angles to be hooked into holed flanges in the hubs. In England it is customary to fit 32 spokes to front wheels and 4o to rear wheels, but elsewhere the usual arrangement is 36 spokes in all wheels. Spokes may be plain (usually about 15 gauge) or double butted, i.e., 15 or 16 gauge at each end and 17 or 18 gauge for the remainder. For tandem bicycles, carriers, etc., spokes of 14 gauge are used.

In hubs there is one row of ball bearings on each side, these bearings being adjustable by screwing either the outside ball race (called the cup) in the hub-shell, or the inside ball-race (called the cone) on the spindle. The driving sprockets are screwed upon the shell, many modern European bicycles, particu larly of the racing class, possessing a sprocket at each side of the hub. These sprockets are of different sizes, so that upon reversing the wheel in the frame, a different gear is obtained, or, in other words, the amount of travel obtained in one revolution of the crank is raised. Another common arrangement is a fixed sprocket on one side, and a free-wheel or floating sprocket on the other, which is very helpful to tourists. In the free-wheel the sprocket runs upon separate ball-bearings and has a ratcheted edge inside, so that the outer sprocket can drive the hub, but cannot itself be driven.

Another form of hub, called the coaster, is widely used in America, less popular in England and oh the continent of Europe, This is a back-pedalling or coaster brake. When pedalling action is reversed, a member is moved sideways on a quick thread in the hub, and is made to expand a phosphor-bronze ring and bring it into contact with the inner surface of the hub-shell.

Variable Gears.

One of the most ingenious inventions in connection with bicycles is the device of varying the gear. It was first installed in the bottom bracket of the frame, forming part of the chain wheel. Soon afterwards a hub gear giving two different ratios—only one of them on a free-wheel—was invented, then a number of others, of which only the three-speed gear has survived in hub form. It is widely used in the British Isles and in parts of the British empire, and weighs about 2 lb. 2 oz. The drive runs solidly on the middle gear, but is taken through a train of small toothed wheels for the high gear (33-1% increase) or the low gear (25% reduction). A small lever on the handlebar or the top frame tube effects the change through a stranded wire cable.

All gear-changing mechanism in bicycles is on the epicyclic principle, by which the toothed wheels or pinions are always in mesh. The principle need not be described in detail here, but the following simple example will explain it : If a toothed wheel A is revolved round, and in engagement with a toothed wheel B, both being allowed to spin freely on their axis, they will spin at the same speeds. If, however, B is then held and prevented from spinning, A will spin much more slowly. Conversely, if A is held in the same way, B will spin more quickly. The drawback of epicyclic gearing in a bicycle is the difficulty of obtaining closer ratios than those mentioned.

Three-speed hubs are also made in England which incorporate a coaster or back-pedalling brake.

Many variable-gearing devices of particular value are used in the Alps and Pyrenees, where the gradients are so long that the cyclist who could not gear sufficiently low to surmount them on his bicycle would be compelled to spend many hours walking. The principle of most of these devices is a loose driving-chain which can be transferred from one sprocket to another mounted by its side. In some cases there are no fewer than three sprockets on the bracket axle, and three others on the hub. A wide range of gears is thus obtainable. This form of gearing is not favoured in England.

Bicycle Tyres.—These are nearly all of the pneumatic india rubber type. There are two parts, the inner tube and the outer cover—terms which explain themselves. The inner tube contains a larger percentage of pure rubber. It is drawn from a tubing machine under high pressure, and emerges in circular form. Some cheaper tubes, however, are still manufactured from flat sheet rubber. Outer covers are built up on a cotton or flax fabric, the process being more or less elaborate according to the quality. The tread, or rubber surface that touches the road, is vulcanized on by a moulding press. Although this process destroys a small per centage of the resilience of the rubber, it also compresses it, with the result that if a piece of flint or glass cuts the tread afterwards, the cut tends to close itself, instead of opening wider. With hand made tyres there is no vulcanization, the parts being joined by a solution of rubber in naphtha. As bicycles fitted with these tyres are considered easier to they are sought for racing pur poses, where the slightly greater vulnerability and cost are of less importance to the rider than speed.

Stiff wires are sewn into each edge of the outer cover, so that when the tyre is in place on the wheel-rim, the pressure from the air tube within forces the wires against the raised edges of the rim, which hold them securely. As the wires are of exactly the right circumference, it is easy to see that if they are forced, at one place, down into the bed or centre of the rim, the wire on the opposite side of the wheel-circle will project sufficiently to enable it to be lifted over the edge of the rim.

Tubular tyres, used almost solely for racing purposes, are light and flexible. The outer cover completely encloses the inner tube, and it must be unstitched or unstuck when there is a punc ture to be repaired. In the Constrictor tyre there are layers of loose threads at the base of the cover, which can be parted to enable a section of the inner tube to be extracted for repair. Tubular tyres are cemented to the rim.

Bicycle Brakes.

The rider brings his bicycle to a standstill by moving levers on the handlebar, which, through thin rods or stranded wire cables, cause small pads of leather, rubber or fibre to press against the wheel rims. These may act on the flat part of the rim, or, with what are known as calliper brakes, on the edges. The advantage of the latter type is that the wheel may be removed or replaced without disturbing the brake, whereas in the other type, the brake rods, with the shoes which hold them and the stirrup-shaped piece which carries the shoes, must be moved out of the way, to make room for the wheels to pass through. Rim brakes are used on front or rear wheels, or both. In America the coaster brake in the rear wheel hub takes the place of the European rim-type brake.

Bracket.

This is the junction of the bottom, seat and chain stay tubes, and carries the toothed wheel driving the chain, and the cranks and pedals by which the rider turns the toothed wheel (known as the chain-wheel). The bracket consists of a cylindrical shell, in which a steel axle is mounted on ball bearings. A tough ened steel crank is secured to each end of the axle, the length of this crank varying from 64 to 7 inches. At the other end of each crank is the pedal, consisting of a framework mounted by ball bearings on a spindle, which screws into the crank. No locking device is necessary, as the right-hand pedal has a right-hand thread, and the left-hand pedal a left-hand thread, so that the pedalling action tends to tighten up each pedal more securely in the crank. The right-hand crank carries the chain wheel, being fastened by bolts and nuts, or welded to it, or forced into it by means of a male or female taper with a serrated surface. This cannot be taken apart after fixing.

In the United States the "one-piece" type of crank is in almost universal use—that is, both cranks and axles are made from a one-piece forging, heat-treated to give spring temper, and the ball cups, cones, etc., so designed as to be easily assembled in the bracket.

The driving sprocket is attached to the crank by being pressed on a shoulder of special design or the sprocket is driven through a lug on the crank, and is easily detachable.

The chain is very light, and accurately made, consisting of mild steel links, fastened by hand steel rivets. Each rivet is covered by a sleeve called the bush, and on most chains, but not all, this bush is covered by a roller which turns freely when the tooth of the chain-wheel or the hub-sprocket bears against it. Chains of half-inch links are almost universal, but one inch is frequently used for racing purposes. The width of the driving surface of a bush or roller is almost invariably one-eighth of an inch.

Bicycle seats are of leather or of a rubber and fibre composi tion, mounted upon springs. Many shapes, sizes and degrees of springiness are available, including special shapes for persons suffering from perineal maladies.

Handlebars are bent of mild steel, usually one inch in diameter, and carry the brake-levers, in addition to the warning bell. Handle bars are frequently covered with some material giving a com fortable hold to the rider, such as celluloid, rubber-sponge, etc. They are used in a great variety of shapes. Generally they bend upwards on "roadster" bicycles and downwards on racing bicycles or when faster speed or more power is desired. Flat handlebars are a useful compromise.

The tandem is designed to carry two persons, both of whom pedal in unison. The pedalling gear, saddle, handlebar, etc., are therefore duplicated. The frame tubes, wheel spokes, rims, tyres, etc., on a tandem are heavier and stronger than on single bicycles.

Statistics.

It is estimated that over 3o million bicycles are in use throughout the world, but there are no means of obtaining exact figures. In a few countries a system of registration is in force, and, accepting this as a basis, the following figures are approximately correct for 1926:— Country. Bicycles in use.

Austria 800,000 Czechoslovakia 600,000 Denmark i,000,0oo France 7,102,000 Holland 2,400,000 Italy 2,000,000 Japan 441,000 South Africa 4i,000 Though the estimates vary widely, it may be accepted that there are, at the fewest, as many bicycles in use in Great Britain as in France—probably more in summer.

The following may be accepted as approximately the annual production of bicycles in the countries named : Country. Bicycles.

Germany 450,0oo Great Britain 680,000 Italy 8o,000 Netherlands 135,800 Sweden 126,092 . . . . . . . . . . . 32 5,000 As the largest producer of bicycles, Great Britain naturally has the greatest export trade. The following are the export figures for 1926: Average value.

Country.

Bicycles. f. s.

Great Britain 280,051 4 6 U.S.A. . . . . . . 5 16 Belgium 8,026 3 7 Germany 5 I Holland 22,57o 3 0 Sweden 4,13o 6 2 Italy 13,067 4 18 The imports of bicycles into Great Britain are very small com pared with the exports; in 1926 only 1,251 were imported, valued at 15,921. A brisker import trade exists in cycle parts, of which £386,034 worth were imported into Great Britain in 1926. It should be noted, however, that during the same year f 1,804,006 worth of parts were exported from Great Britain.

Experiments in adding engines to bicycles to render them inde pendent of human propulsion began in 1885 (see MOTOR CYCLES).

(B. W.

BE.)

bicycles, wheel, steel, england and wheels