The record-union. [volume] (Sacramento, Calif.) 1891-1903, 1899-02-20
OF INTEREST TO CYCLISTS.
CLAIMS OF CHAINLESs GEARS
ONE SIDE GIVEN.
Which Is the Speediest Tire?-Get-
ting Over Obstacles-Accident
Statistics-Nippert's Appeal.

So profound and general is the inter-
est Of the debate between promoters
of chainless and defenders of chain
wheels that we step out of the usual
line to present Professor r. c. Carpen-
ters (of Cornell University idea con-
corning the spin-roller gear, which, by
the way, is an extension of the Sagef
gear idea. The Sager has one gear
wheel fitted with rollers turning on
pivots and meshing into dove-tall
cog; the spin-roller has both gear
wheels fitted with rollers on pivots and
meshing into each other. The Columbia
and similar gear, as is well known, is
q bevel cog meshing device. Professor
Carpenter is quoted as saying that tests
have shown that the spin-roller gear
has an efficiency of 9715 per cent. under
heavy load. 1t is well known that the
spring of. the crank hanger tends to
throw bevel and other like gears which
have line contact out of line, thus CIV
ing rise to an irregular ratio of velocity
and consequently pulsating sensations
in the feet The spin-roller is so con-
structed that when one roller rolls
against another the working surfaces
are in point contact, and for this rea-
son will stand any required degree of
DETECTION. OF course when power is
applied to chain sprocket there is
great cross strain, and in the usual
bevel gear wheels corresponding
spreading. With the spin-roller gear
these faults are avoided. With this
simple mechanism the line of pressure
is always vertical, upward at one end
of the shaft and downward at the
other. The spin-roller gear machine
starts off with wonderful life the mo-
ment pressure of the foot is applied to
the pedal. Back-lash is extremely
small and the increase is SO slight that
no adjustment is ever needed" Now,
since it is desirable that all sides be
heard, we shall take pains to ascer
tain the claims of the bevel and Sager
gears as against this opinion concern
the spin-roller.
Cycling West: Theoretically consid-
ered the best tire from a mechanical
standpoint is the smallest and hardest
one possible, when it comes to easy
running qualities, and yet we gather
from an eminent exchange that Pro-
fessor Carpenter, in charge of Cornells
mechanical experiment station, has
shown "conclusively'' that, other things
being equal, the larger the tire the
easier runs the wheel. This is particu-
larly so in case the rider is of more
than average weight. 1t is not mat
ter of friction by contact with the
ground, for, that being of the rolling
type, amounts to practically nothing
but it depends on the loss of power in
COMPRISING the tire. On a two-inch
tire the rider of average weight causes
very little compression of the tire
tread The tire has great bearing
surface. Take half an inch from the
diameter of the tube, however, and as
it rolls along a constant indentation
and release result. Here the power is
lost, and hence the conclusion Pro-
fessor Carpenter says that a poor two
inch tire will run easier than the best
one and-a-half- Inch tire that was ever
made. A difference of over Is per cent
in the running qualities of a wheel is
attributed to the kind Of tire used. A
single tube always proves faster than
the double tube, but this may be due
partly to the better material employed
in making the former. Funny what
conclusions scientific men will arrive at
occasionally
"A skillful rider will be able to take
light wheel over almost any obstacle"
says a veteran rider, whereas under
the same circumstances a clumsy rider
would smash a heavy machine 1t is
done by slightly raising the front wheel
as the obstruction is reached, and then
pressing heavily on the pedals and
throwing the weight forward just as