Los Angeles herald., 1909-01-24
WEIGHT ON TIRES
IS BIG PROBLEM
DISTRIBUTION MUST BE MAT
TER OF COMPROMISE
WEIGHT ON ANY ONE OF FOUR
WHEELS is DIFFERENT
Designers Are Making Exhaustive
Study of Maintenance Expense,
with Future Benefit
to Owners
OF THE many problems met in
automobile design that Of weight

OF THE many problems met in
automobile design that Of weight
distribution is not the least i'm
portant, nor is it one that has received
the attention of the designer in the
measure it deserves, says j. D. Max
we'll in the Co-operator.
Like all the tasks imposed by mod
ern automobile construction weight
distribution must be largely a matter
of compromise. In this respect the
problem resembles much that involved
in spring design in which becomes evil
dent the difficulty of providing a spring
that will give equal resiliency in an
empty car as well as in one that car
ries its full quota of passengers. Sim
ilarly, weight distribution becomes a
somewhat complex proposition when it
is considered that it is impossible to
distribute the dead weight of an auto
mobile in such manner that the me-
chanical equilibrium will not be inter
fered with when the car is run with
load or without it.
These questions, however, while in
teresting to the engineer are Of less
Importance to the average automobile
user except in the relation they bear
on his tire consumption. Here, too, it
is impossible to strike a fair mean.
L
question to secure for one tire as little
wear as is encountered in the other,
even though all four tires be of uni
form quality and structure. Even in a
car carrying the greater part Of its
weight in front the greater wear is in
Volved in this connection that the pro-
pulsion of a motor vehicle differs from
that of a horse-drawn vehicle in that
the latter is pulled over the road sur
face, while the former is pushed by the
tractive effort transmitted to the rear
or driving wheels. In consequence of
the driving stress, the rolling friction
with the road and the slippage that is
absolutely unavoidable the tires of the
rear wheels encounter most of the wear
to which the automobile tire is subject.
AS far as the weight of the car itself
is concerned, regardless of its distri-
button, it is common experience that
the light car produces the smallest tire
bills. For it has been proved by most
competent authority that the life Of a
tire is inversely proportional to the
cube of the load which it supports, so,
that if the load be doubled the average
wear and tear of the tire will be multi
piled by eight.
But there are points that are worthy
of attention, some of them having to
do with the general design of the car
and with the manner in which the
power plant and transmission is sup
ported. 1 know, for instance, and so
do many others, that in the case of
cars in which power plant and trans
mission form a unit supported at three
points road shocks are more readily
absorbed by the frame work and sus-
pension means-which accommodate
themselves to the distortions to which
the INEQUALITIES of the ROAD SI1rfa %
give rise. In a more rigid suspension
system the entire road shock is first
received by the tire with consequent
disastrous results to its life.
That in a car in which there is more
weight on the left side than there is on