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.
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.
[Illustration: 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.
[Illustration: COLUMBIA HUB.]
Few people realize the torsional strain exerted on the rear hub when
full power is applied to the pedals in climbing a steep hill where the
momentum is not sufficient to carry the rider far and where the pull
is more or less continuous on successive groups of spokes as the wheel
revolves. In addition to this pull on the spokes is to be considered
the weight of the rider, the greater proportion of which is sustained
by the upper half of the rim and the corresponding spokes and not by
the portion of the wheel nearest the ground as just explained. It will
be understood that each group will be subjected for an infinitesimal
space of time to a maximum pull as the chain passes over the sprockets,
the strain being accentuated at each downward stroke of the pedals, so
that a single spoke when at a very high tension as compared with its
neighbor frequently snaps when directly in line with the chain at the
proper instant of time. Originally all hubs were made of what is known
as gun metal, the flanges of the hubs were very thick and tapered
toward the centre of the hub. They were made in this manner to provide
sufficient room for tapping and threading the hub flanges so that the
direct spokes which were in use at that time could be directly threaded
into the hub.
[Illustration: KEATING HUB.]
The 1898 tubular and barrel hubs are, of course, the result of many
processes. Some of them are turned whole from bar steel; others are
stamped out of sheet metal; some of them are formed out of tubing,
and a few of the cheaper makers use malleable iron or cast steel for
this purpose. All of the spokes used are made of either a special
drawn steel wire or a piano wire. They all possess great torsional or
twisting strength, and the tensile strength or stretch is from 500 to
800 pounds. They average in gauge of thickness from 13 gauge, which is
expressed by the figures .095, to 15 gauge, which is expressed by the
figures .072. Front wheels have from twenty-four to thirty-six spokes
and rear wheels from 28 to 40 spokes, and while it is true that all the
makers now use a tangent spoke there are a great many variations in its
use. The majority of them tie their spokes to each other where they
cross. There are a great many of the makers who do not tie them at all,
there being some difference of opinion as to the benefit to be derived
from this treatment.
Those in favor of tying spokes say that tying two or more spokes
together at the crossing some distance above the hub shortens the
leverage from the rim and practically gives the wheel an additional
hub; that they are also stiffer against side or lateral strain, and
that the only good tangent spoke is one that is tied at the crossing
with its mates. Those who are opposed to tying spokes say that tying
them together makes them too rigid and inflexible, and that the
process of wiring them and soldering them together has a tendency to
crystallize the spokes at this point owing to the heat required to
solder them. This part of the argument, however, has been met by not
wiring and soldering the spokes at the crossing, but by pinching on
them at this point a metal clamp such as is used on the Humber wheel.
The opponents of tying the spokes assert that the very stiffness and
rigidness which the wheel possesses when the spokes are tied has a
tendency to also crystallize them at the hub flanges as well as cause
them to break. It may, however, be here stated that the pneumatic tire
acts as a buffer, and that the use of heavier rims and more spokes,
which are prominent characteristic features of 1898 wheel construction,
insures the whole wheel a greater factor of safety than heretofore
known in construction, and therefore less liability to get out of true.
[Illustration: STERLING HUB.]
The Raleigh cycle, an English production, and which came into
prominence in this country because it was Arthur Zimmerman’s great
mount, had wheels in which two-thirds of the spokes were direct from
hub to rim, and the remaining third were crossed at a tangent. It was,
however, a sort of a compromise between the direct and tangent spokes,
and ultimately led the makers to use tangent spokes only.
THE WOOD WHEEL.
A number of attempts were made a few years ago to introduce hickory
wheels in place of the wire suspension wheels, among the most notable
being a bicycle built by Sterling Elliott, and called the “Hickory.”
The frame was built of tubing as was usual, but the wheels—hubs,
spokes and rims—were made of hickory, the spokes being known as radial
spokes. In order to maintain its rigidness and to carry the pneumatic
tire the rim was surrounded by a metallic band in which the tire was
placed. The public did not take to this style of bicycle wheel, and
their manufacture was discontinued, not however before Mr. Elliott
placed a pair of these ball bearing hickory wheels with pneumatic
tires on a high wheel sulky, which had been converted to carry these
wheels. The result was astonishing, and today no other wheels are used
on sulkies but 28 and 30-inch bicycle wheels with ball bearings and
pneumatic tires, and the result of their use had been that the times of
the trotting horses have been reduced six to ten seconds per mile. Of
course the present type of sulky is built specially with arched axles
and frames to carry these wheels, and the old high wooden wheel is as
rarely seen on the trotting track as the good old “ordinary” is seen on
the bicycle track.
[Illustration: WOLFF-AMERICAN HUB.]
Hubs using a spoke having a hooked end with a rivet head on the end
thereof, which are drawn through the holes in the flanges of the hubs
are not as popular as formerly, a great many of the makers having
departed from this method, now using a spoke which is straight from
the hub to the nipple. They claim for this method that the absence of
the bend in the spoke minimizes the liability of crystallization which
is so apt to exist in spokes of the bent variety. This style of direct
tangent spoke was first shown in this country in 1892 by the makers of
the Liberty, and among the most prominent users of this style of hub
are the makers of the Spalding, Victor, Crawford and the Iroquois, and
which are almost duplicates of the Liberty hub. The Keating differs
somewhat from these, inasmuch as the projections from the sides of
the flanges are not opposite each other, but are placed alternatively
to receive a single spoke. The Liberty hub may be best described as
follows: It is a one-piece hub, with lateral projections from the
sides, or flanges, and these projections are drilled to carry the heads
of two straight spokes, each spoke running in a straight line to the
opposite side of the rim. The usual style of hub has a plain circular
flange with holes drilled in it to receive the spokes; this makes it
necessary to bend the spokes at a right angle at the end, where they
are inserted over the face of the hub. This sometimes rendered them
liable to break, and, therefore, what is known as the direct tangent
spoke was invented.
[Illustration: CLEVELAND HUB.]
[Illustration: LIBERTY HUB.]
[Illustration: PLYMOUTH RIM JOINT.]
In this method of construction the hub end of the spoke is not bent,
but has a head made upon it like that of a rivet; the strain comes
in a direct line from end to end of the spoke, and the entire spoke
is in tension. The early makers of direct tangent spokes found it
necessary to make these of a somewhat heavier and softer wire than the
tangent spokes which were bent at right angles to form a hook. The use
of this soft thick wire proved rather objectionable, as it was with
difficulty that the wheels could be kept true, and the spokes were
apt in compression to slide through the end of the flanges on the hub
and make a noise. However, all makers who use direct tangent spokes
are making them very much thinner than heretofore, and of a harder
quality of wire. In fact, the makers of the Crescent (also having these
direct spokes) use probably as light and as thin a wire as any of
the makers who use a spoke with a bend at the end. The makers of the
Wolff-American (who are also renowned as great makers of wire) claim
that there is no necessity for the use of a direct tangent spoke if
the proper quality of wire is used for making the spoke which has its
end bent at right angle, and that while it is undoubtedly true that
the spoke bent at right angles at the end does stretch its fibres on
one side of the bend and compress them on the other, still, if the
spoke flanges and spoke holes and the nipple holes at the rim were only
drilled at a proper angle to each other, there would be no danger of
a broken spoke. All 1898 spokes are swaged and butt-ended. Formerly
spokes were known as upset and butt-ended. Upsetting a spoke consists
in heating the ends and driving it backwards, thus making it thicker
than the rest of the spoke. The objection to this practice consisted
in its tendency to crystallization where the “upset” ended. Swaging
a spoke consists in leaving the butt ends of the spoke the original
thickness of the wire, and reducing the diameter between the ends by
a hammering process in a machine built for the purpose, to a gauge or
two smaller than the original thickness. This method of making spokes
reduces the weight, leaves the heavy portion where it is most needed,
and adds great tensile strength to the spoke. In making a spoke by this
method the wires are at first made somewhat shorter than the length
required, as the swaging has a tendency to draw them out in length, and
in the best of modern practice of spoke making the threads are rolled
on by machinery instead of having them cut on by a die, as formerly.
The rolling process has this advantage, that it does not reduce
the diameter of the spoke and cut away so much material as the die
threading process.
VARIOUS STYLES OF HUB AND SELF-OILING DEVICES.
The makers of the Sterling, who have always used a direct tangent spoke
in connection with a hub having a corrugated flange, show a new hub
this season. It is machined from a piece of bar steel. The flanges or
teeth are somewhat like a small rear sprocket. They are, however, of
the double hollow construction, and on the rear hub on the sprocket
side part of the flange is cut away on the outside, leaving a large
opening in the tooth, which sits between the teeth of the sprocket
wheel, so that a spoke can be readily inserted without removing the
sprocket wheel, and through the first-mentioned hole the spoke is
pushed forward and upward through a buttonhole, and is then slid in a
T-slot either right or left to its seat, each tooth in the flange thus
carrying two spokes, one to each side of the rim. On the left hand side
of the rear hub the construction is reversed, the flanges not being cut
away as on the right hand side, and the spokes are inserted through a
similar opening as before described on the inside portion of the hub
and flange. On both sides of the front hub a similar construction is
employed as that in use on the left side of the rear hub.
[Illustration: STEARNS SELF-OILING CRANK-HANGER MECHANISM.]
The Windsor hub is of the corrugated pattern, having a double flange
in which the spoke holes are drilled, and with a buttonhole device for
inserting the same.
The Crescent hub is built with a straight flange over the body of
the hub, and this hub flange is turned over, forming a wide bearing
surface, which is drilled for the spoke holes, and underneath this
outer edge a buttonhole device is placed in the body of the flange by
which the spokes can be easily removed and replaced, and without the
removal of the rear sprocket.
The Columbia hub has a series of studs inserted in the body of the
hub and through these studs holes are drilled, and the direct tangent
spokes are inserted therein.
The Eclipse hub is turned from the solid bar of steel and has two
flanges at each end; these flanges have alternate slots and holes. A
T-head spoke is inserted by passing the head down the slot and pushing
it sideways down the opposite hole in the adjoining flange.
The Wolff-American hub, which was one of the first large tubular
hubs shown in this country, is made of steel tubing without either
projection or flanges, but has a buttonhole device which greatly
simplifies the replacing of spokes. Inside the hub and underneath the
spoke holes is placed a dust-proof ring which prevents the intrusion of
dust into the bearings. They use a hollow axle containing an absorbent
wick saturated with oil. In the axle over the wick is a minute hole on
each side, through which the oil is drawn by centrifugal force by the
revolving of the balls, and thus is supplied to the bearings in the
crank-hanger in the same way and automatically the supply is regulated
by the demand.
The makers of the Cleveland also have an automatic oiling device on
their hubs. The wheel and crank axles are tubular and hollow. This
space forms an oil receiver. In order to prevent the oil from escaping
from the hollow axles the end is plugged with a screw; under the head
of the screw is a piece of packing, making the joint perfectly tight.
The flow of oil is regulated by wicking drawn through small holes
drilled in the axles close to the bearings. These holes are plugged so
tightly that the oil will not escape when the bicycle is not in use.
The moment the wheel begins to revolve capillary attraction produces a
drop of oil at the end of the wicking.
There is this to be said in favor of both the Wolff-American and
Cleveland devices that there is no danger of losing any oil cups, and
that after a long, dusty ride oil has not surrounded the hubs and crank
hanger bracket to which the dust can be attracted, and the bicycle is
therefore very much easier to keep clean. The makers of these styles
of automatic oiling devices claim that they will carry a season’s
supply of oil, but even if this should not prove to be true, it is only
necessary to lay the bicycle on its side, remove the plugs in the ends
of the axles and pour oil into the reservoir.
WOOD RIMS.
As has been already noted in the article on tendencies, the wood rim
has undisputed possession of the field, not a single American maker
cataloguing a steel or other metal rim. Even the makers of the Eagle,
who formerly used an aluminum rim, now offer it as an option only,
and show all their samples with wood rims, and this may again be
regarded as a reversion, the original type of the old “Dandy Horse”
velocipede having been built with wood rims and shod with iron, the
only difference now being that we use wood rims shod with air, and when
the “good old ordinary” came in vogue steel rims were introduced. On
the ordinary, however, which had only small solid tires, the rim was
a narrow grooved one, and possessing, as it did, very little lateral
strength, it had a great tendency to buckle under the force of a blow
or a collision, and when the safety came in vogue this same idea of rim
construction was carried into it. An improvement was made, however, in
their construction in making them of a double hollow construction which
increased its lateral resistance, but in case of accident made them
extremely difficult to repair. A little later, when the cushion tire
arrived, the single rim and the double-hollow rim were used, making
them, of course, of a larger cross-section to fit the tires used,
and when the pneumatic tire was invented the steel rims first used
very much resembled a band of hoop iron used on an ordinary washtub.
Afterward double-hollow rims were used on bicycles with pneumatic
tires, and single rims which were fluted or corrugated in order to give
them additional stiffness were also used. In 1891 McKee & Harrington
of New York City, the makers of the Lyndhurst, introduced a bicycle
having wood rims. These rims were made of second-growth white ash and
were of the single-piece variety, joined together with a long, tapering
“skive,” and the entire rim and joint were covered with natural color
Pongee silk, which was glued on, producing a watertight rim. This rim
was the production of Mr. Charles Harrington of this firm, who for
many years before entering the bicycle business had been known as a
practical wood worker. Makers and riders were very skeptical of the
value of the wood rim, but after a few well-known racing men had won
a few track and road events on them and the wood rim had shown its
utility and value by its increased resiliency and speed, and that it
was stronger across its lateral plane than a steel rim of any type
could ever hope to be, and with its non-liability, therefore, to buckle
in a collision, it became a popular thing, and in less than two years,
as has been seen, it has completely routed the steel rim out of the
American market. In England, however, owing to the large use of the
detachable tire and the moist climate, its advance has not been so
rapid, but it is coming along even there, and it bids fair to supplant
the steel rim there in another season or two. One-piece rims are not so
largely used as heretofore. The laminated rim as now made, which was
originated in 1893, seems to be the most popular one on a majority of
the high cost bicycles on the market. It is to be noted, however, that
the rims of this season, almost without exception, are broader across
their face and thicker through in section, which is an especially good
feature, inasmuch as it gives the tire a larger and firmer bed to rest
upon, so that it is not so liable to be cut by the edges of the rim.
Of course, making the rim broader and thicker and heavier takes away
some of the points which were formerly used in its favor, notably those
of light weight and resiliency. The up-to-date wood rim more closely
approaches in weight the lightest possible form of steel rim, and it is
a notable fact that the wood rim is the only prominent contribution in
bicycle construction that America has presented to the world, and there
is good reason for this, however, because our Yankee and our Western
wood workers have long been famous for their progress in the art of
wood working and wood bending. One of the most famous wood benders is
Mr. H. H. Shepard of New Haven, Conn. In 1889 he had the temerity to
send to the Paris Exposition, in the care of a French exhibitor, not
wishing to go to the expense of a personal representation, some samples
of his wood bending. These samples came in direct competition with the
great Vienna, German and French wood benders, and although Mr. Shepard,
as before stated, was not personally represented, to his great surprise
the Commissioners unanimously awarded him the only solid silver medal
for superior excellence in that department.
[Illustration: PLYMOUTH RIM.]
[Illustration: KUNDTZ RIM.]
This same Mr. H. H. Shepard (who, by the way, is a six-footer
and bearded like a patriarch), in a lecture in New York City on
wood-bending before the master mechanics of the Carriage Makers’
Association, placed his audience in good humor with him when he
declared that his earliest recollections of bending were when, while
a boy, his mother bent him over her knee to keep him straight. The
Shepard is a one-piece wood rim of second growth white ash. The ends
are butted together and an ovoid piece of hardwood is inserted over
the butt ends on the inside of the joint. This insert extends about
three inches each side of the butt-ended joint and is flush with the
remainder of the rim. These rims are bent by compressing the inner
surface in a hydraulic press without stretching the outer periphery
of the rim. This method shortens the inner surface about six inches,
thereby greatly toughening the inner surface of the wood. The average
weight of the steel rim formerly used was about 24 ounces. The average
weight of the wood rim used for a cemented-on tire as first made was
about 14 ounces. The average weight of the wood rim in use today is
probably about 18 ounces.
VARIOUS MAKES OF WOOD RIMS.
Another popular rim is called the Winona. The process of making the
Winona rim is as follows: There is about six inches difference in the
circumference between the inside and outside of the rough rim. The bars
being straight before they are bent, it is obvious the inside must
stretch or the outside upset. The process used prevents stretching of
the outside fibre of the rim, and actually upsets the outside as well
as the inside, thereby interlocking the entire fibre and doubling its
original strength. They use a plain beveled dovetail joint. They also
make a laminated rim, and what they call a screwed rim. This rim has
screws at stated intervals running crosswise of the rim, coming just
under the seat of the groove, as the greatest strain on the rims is
caused by the spokes, which sometimes result in splitting the rim. They
have undertaken to overcome this, or, rather, to strengthen the rim by
putting in these screws. The illustration shows a sectional end view
of the rim and the manner of inserting the screw from side to side.
The Winona rims are made of butt cuts, and they use what is known as
a second cut rock elm only for their rims. Rock elm has dark streaks
running through and is dark in color, differing, therefore, from second
growth white ash, which is very light in color.
A well known wood rim is that known as the Plymouth, which consists
of a single piece of rock elm bent, jointed and turned on a lathe.
The joint in the Plymouth rim is so constructed that the ends come
together square across. It consists of a series of tongues and grooves
interlocking, the tension of the spokes making them tighter instead
of straining them apart. One of the special features of the Plymouth
rim is the fact that the spoke holes are eyeletted and are thus made
waterproof. The illustration shows their reinforced joint.
The Kundtz is known as a double reinforced rim. It requires two rims
to make one, and the manner of cementing one rim into the other, with
a section of thin wood between them, which has its grain running
crosswise to the two main sections, as shown in the illustration,
produces one of the strongest wood rims made. Another improvement in
this make is the fact that its glued joints are not exposed to the
weather, which has been considered a detriment in building up rims of
the old style.
One of the most popular rims is that which is known as the
Fairbanks-Boston. A laminated wood rim is one, as is now quite
generally known, formed of curvilinear maple segments, indissolubly
cemented into perfect unity under enormous hydraulic pressure,
which, because of this principle of jointure, remains perfectly true
both laterally and in periphery, while the transverse grains of the
adjoining segments or laminæ absolutely prevent splitting along the
line of spokes in the impact of collision or shock. The fact that
no single joint extends through the rim effectually overcomes any
tendency to break off in any direction or manner. The makers use three
curvilinear segments of Pennsylvania rock maple. Each segment is planed
on both sides to a thickness of mathematical exactness throughout the
entire length, thus insuring absolute unbroken contact when cementing
to the adjoining segments.
The overlapping ends of each segment are by special machinery then
“scarfed” to feather edges, obtaining laps equal in length tapering
on an angle which experience has proven correct. By this process of
bending the rims do not require steaming, which disintegrates the fibre
of the wood, and in cementing the joints the three laps are placed at
points of the circumference of equal distance apart, rendering the
tensile strength absolutely uniform in all parts. In compressing the
segments of the rim together hydraulic pressure is applied to the
periphery of the rim after the application of the cement. An enormous
pressure is applied equally at all circumferential points, and it
is maintained until the cement has completely solidified the three
independent segments into the form of a permanent circle. They also
make what is known as a covered laminated rim, the enveloping fabric,
which is a special quality of pure Irish linen, fitted exactly on the
rim and secured permanently with liquid cement, and it is estimated
that enclosing the rim in this manner imparts at least 30 per cent. to
its strength, with a corresponding increase in is resiliency, and these
rims are therefore recommended in damp climates, and for use on tandems
and other multicycles. All the makers furnish their rims in a natural
varnish, and also stained in imitation of rosewood and other woods, and
many of the makers in addition to this furnish the rims painted and
striped in different colors, in many instances matching the colors of
the enamels used on the frames.
At the ’96 Cycle Show papier-maché rims were shown, for which great
claims were made and a great deal expected, but none of the well-known
manufacturers adopted them, and the company that brought them out has
since gone out of existence. Trials within the knowledge of the writers
proved that these rims as made then were not practical.