Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1899-06-21
FIGURING THE GEAR.
4 WheeIman Explains That Generally Mis-.
understood Term. Gear"

understood" said local wheelman.
yesterday. 'To old riders 1t seems
hardly possible that many should he
ignorant In this respect, but the testi
| mony Of dealers shows that not only
the new riders, but also those of two
or three years experience, fail to
grasp the term as 1t is used An illus
tration of this failure to apprehend
the how and why Of gear is afforded
by the following question sent to the
New York Sun: "A 2s-inch whee,
geared to 81 and 30-inch when geared
to 81; will one cover more ground with
one revolution Of the pedal than the
other?
The answer is that neither travels
further than the other The gear OF a
bicycle, strictly. is its driving mechan-
ism, the chain and the sprockets. or
the bevelled cog wheels. It's common
use in relation to bicycles, however. Is
different and is anomalous. 1t Is en-
ployed to represent speed attainment
through the multiplying character of
the gear, and even this is not repre-
scented directly. The figures as used
are a heritage from the high-wheel
days when strong riders rode as large
a front wheel as they could. because
the larger the wheel the further If
Wi
pedals. SO man who rode wheel 50
inches in diameter was riding a SITTER
gear than the one using a 5O-incb
wheel. The diameters then expressed
the gear idea. With the advent OF the
safety the plan was retained, and when
wheel 80 inches in diameter had its
gear 50 arranged that it revolved twice |
with every turn of the pedals, it was
said to be a bicycle Of so gear. because |
the two revolutions made il equivalent |
to wheel so inches in diameter. thus
the multiplying power has continued
to be figured and represented by |
figures indicating always the eouiya
lent diameter of the rear wheel The |
teeth on the front and rear sprockets
are cut uniformly one inch apart. and |
therefore the count of them has been a
convenient way Of determining the |
relative sizes of the sprockets. which |
is the fact upon which the gear de-
Ponds. A front sprocket having two
ana half times as many teeth as the |
rear one, will be two and a half times |
as big. and the rear axle with the
wheel will revolve two and a half times |
while the front sprocket, crank axle. |
cranks and pedals are revolving once. |
The rear wheel of IS inches in diameter
then travels as far with every turn of
the pedals as one of a diameter two
and a half times as big as 2s inches. |
which IS 10 inches. and that is said to
diameter and one of 20 gear, making
any wheel equivalent to that diameter.
would travel about 300 inches, or Is
feet inches 1t would not make any
difference whether it was a two-inch
wheel or 53-inch wheel, so long as it
was geared so as to be equivalent to
one of 20 inches the result would be the
same. This method Of referring to
gears has been much criticised. and
there is no justification of it except
custom. 1t would be much simpler and
more accurate to speak of the gear by
the multiple Of motion it represents.
Then a gear of the size used in the
illustration would be called 2h gear in
stead of 20 gear. An 81 gear would
be called a 3. and others would be rep
resented by integral numbers and frac-
| tions. such as g $40. for what is now
called a % 2-5 gear. This would enable
riders to find the equivalent diameter
of their wheel simply by multiplying
its actual diameter by the figures
given. The equivalent diameter cor
| responds with the relative superiority
| of the front sprocket over the rear one
as shown, and for this reason the
| process of ascertaining gear is to
| divide the size of the front sprocket
| dts number of teeth by that of the
small one and multiply the rear wheel
diameter by the quotient. 1t is ex
pressed by the rule of three thusly.
| AS the number of teeth on the small
| sprocket is to the number of teeth on
| the large sprocket, SO is the actual
diameter Of the wheel to its equivalent
| diameter which is to say, the gear.
| To avoid troublesome fractions it will
be found easier usually to first multi
ply the large sprocket figures by the
| actual figures of the actual diameter
and then divide by the rear sprocket
figures"
| 1t may not be an uncommon thing.
these days. but after climbing the hill
on hot day and coming into the re-
| freshing shade of the broad veranda
| 20 - ir