The morning news. [volume] (Savannah, Ga.) 1887-1900, 1897-08-20
THE CHAINLESS BICYCLE.
A Cornell Professor Finds Serious
Objections to Its Use.


From the Detroit Free Press.
DR.. Rolla c. Carpenter, professor of ex-
perimental engineering at Cornell Univer-
sity, has been doing a great deal Of ex-
perimental work recently in an endeavor
to find the relative merits of the bicycle
driven by a chain and one of the chainless
variety His deductions are very interest
ing. In his statement ne says:
Our Investigations are not entirely COM
pleted at the present time, but it seems
safe to announce that all of the tests indi-
cate that no form of gearing can possibly
equal the best chain for efficiency and dur
ability. Some of the resultS0f the tests
may be interesting, and it may be briefly
stated that the friction with the best chain
varied from half to three-quarters of one
per cent, and this result was obtained
with a chain which had been in use on a
wheel that had been ridden for more than
1900 miles by a rider weighing nearly 200
pounds. This would serve to show that
high-grade chains can be and are made
which do not change their form by wear
an amount sufficient to affect the friction
Tests were made on a large number of
other chains, and the friction was found
to vary from 2 to 5 per cent depending
upon the condition of the chain, the
method of construction and details Of the
design. The highest friction we have
found, even in the case of an old chain
which did not fit the sprocket properly
did not exceed 10 per cent, although L am
willing TO coneede that a considerably
higher friction might in some instances
be found.
Regarding the use of gears, extensive
investigations have been made from time
to time which show the amount of power
lost in friction. The very best recorded re-
suits with spur gearing are very nearly
equal to those obtained with the ordinary
chain when the gearing is in the best con-
dition and working accurately i'm line and
position. The best kind of bevel or spiral
gears, a form which must be used in bicv-
Gle work show about three times the fric-
ton Of the spur gears, and since two pairs
must be used on each bicycle, about four
times as much friction as the ordinary
chain will be developed. and six to eight
times the friction of the very best chains
There is another serious objection to
the use of gears, arising from the fact
that the least change in position of the
point of contact of the gear from it's nor
NAL will cause great increase in friction
and In loss of power over that stated in the
preceding discussion. This indicates that
the gearing is essentially untitled for a
frame which must from the very nature
of its use possess great elasticity and flex-
ibility.
In our investigation the friction of sew
eral bicycles running under ordinary con-
ditions was measured This for the very
best wheels under heavy working condi-
ton was found to be from to per cent
Of the power supplied. while with some
of the poorer wheels the friction was %
to 10 per cent.
zone OF the noted manufacturers of high
grade wheels kindly permitted an oppor-
tunity OF comparing a chainless wheel
which was constructed In the most ap-
proved manner and with the friction re-
duced to the smallest possible amount
with the same kind OF wheel equipped with
the best chain. The results were uniform
~ from . to s per cent In favor Of the
wheel with the chain, or just above the
amount that could have been predicted
from previous tests of gearing.
THE chainless wheel also developed one
extremely bad feature, and as this Is in.
herent in all methods OF gearing. Il may
be perhaps worth mentioning. with an
the chain wheels the percentage Of fric-
ton or loss OF power remained essentially
constant az all speeds. but with a geared
or chainless wheel the percentage OF frlc-
tion increased as the speed diminished.
This would make the chainless wheel very
Objectionable for climbing hills. since at
that time the speed must be STOW. and all
the power OF the rider must be used to
propel the wheel forward