Harrisburg telegraph. [volume] (Harrisburg, Pa.) 1879-1948, 1917-09-04
RIMS IMPORTANT
FACTOR OF TIRES
Firestone Tire Expert Tells of
Standardized Advantages
and Other Rim Helps

In the early manufacture of tires.
II was realized that the beads should
be constructed in shape and measure
: ments to standard. The importance
or secure fastening and correct seat
/ ing or tire on rim has been evidenced
oy the care and rigid specifications
whlch tire manufacturers have fol-
lowed in the construction of beads.
although not adhering to any par
ucular standard as to construction
OF side walls, tread portion of tire,
number of plies of fabric or thick
ness of materials.
AT present both American tires
and rims are made,to their respective
standards or approximately so, and
thereby safety and efficiency are in
sured to large degree: it is also
possible for customer to use tires
OF any American manufacture.
The guarantee of all standard COM
panles makes it very clear that the
warranty does not cover tires used
on rims which do not bear the Of
| hcial inspection stamp of the Society
OF Automotive Engineers.
On account of the danger of rims
applied to wire wheels being drawn
out OF round and especially the dam
ger of such rims becoming under
size in circumference, the official in
7
completed wire wheels. In the future,
wheels are not acceptable to any tire
comany and tires are not guaran-
teed thereon unless such wheels bear
the inspection stamp.
Even though rims bear an inspec-
ton stamp, it should not be taken
for granted that they are all right
sometimes they are damaged in ap-
| plication to wheels or in service
/ tharafora IL iS ad bIa 70
carefully.
Some straight-side rims on the
market were manufactured by SIM
ply bending down the clinches of the
regular stock used for cIincher
, rims. They are not a good fit for
straight-side tires and in many in
stances account for breaking above
cables, pinched tubes and other in
1uries. Some types of split rims, par
ticularly of the straight-side styIe
are difficult to tighten uniformly on
the wheel. Under such circumstances
the rims spring out of round, also
shift sideways at split. If the clamp
ing or fastening device is not correct
the rim will likely sag in places and
wherever it is low or much out of
round the tire will be high from the
rim seat; pinched tubes and blow
out are not an uncommon result.
~seNNhOA AAollA Ili1l cutting is not
TO be obtained by any particular type
of tire but depends rather upon the
design, quality and usage. No good
tire of any standard type will be cut
by any standard rim, if properly
used. On the other hand, any type of
tire will be injured if subjected to
abuse. Under imitation dented and
irregular rims, excessive loads, tire
filters and stiff reliners are the COM
fNF
above beads.
The fianges of a rim may be bat
tered down and become rough from
running a tire debated for a consid-
cradle distance; the next tire applied
is sure to be cut above the beads.
Tires carrying heavier loads than
those for which they are designed
may develop breaking at the beads
where engaged by clinches of rim.
II rims become rusted from water
working around beads when tires
are run soft or through neglected
cuts in the tires, or from neglect to
put proper fittings on the valve stem.
the rust should be removed with
emery paper and rims painted with
a coating of aluminium, graphite and
oil or other good preservative solu-
tion. When applying a tire, be care
full that the flap does not slip under
meath bead and crowd it in clinch of
rim.
Under the impression that they
are oversize, it is not uncommon for
tires TO be applied to rims of wrong
slze-for example, using 36x41k tire
on 36N4 rim. The diameter of this
rim is approximately 2S inches and
the diameter of the beads of the tire
approximately 81 inches, or approx
mately 26 inches, therefore it be-
comes necessary to stretch and strain
the beads considerably. Moreover,
the II Inch beads are not construct
ed TO mt 4-inch rim and will not
engage properly in the clinches. Good
results cannot be secured when the
beads are strained and crowded in
thlS manner. The correct oversize tire
for 36x4 rim is 37x41a.
When removing tires from rims,
do not overlook pushing valve stem
of tubes up far enough in tires so
so that 1t will not be necessary to
pound fastening device of rims in
order to release beads of cases. Rims
are sometimes dented from pounding
them in this way.
When chafing, cutting or breaking
extends all around beads on both
sides, repairs are expensive and not
to be recommended. II the injury
only extends for a short distance
over one or both beads, a skillful re-
pairman can make a good job at a
reasonable cost.
A successful tire must be properly
designed, q. e., the shape suitable
for the size of the section and a cor
rect balance is an essential thing;
the tire must be strong enough to
render good service but not too
thick, heavy or stiff to prevent dis
tribution of strains and stand the
fieXing action in side walls.
Extra thickness and weights add
ed to tires will cause additional heat
and interfere with the radiation.
Tread attachments or covers creep,
chafe, heat and stiffen the tread to
such an extent that fabric breaks are
caused by a localized hinging action
in side walls.
1t is not advisable to use reliners
in new tires because they tend to
flatten the tires similar to under-in-
fiation, and, in many ways, interfere
with the design and intended action.
II made of flexible material. and we'll
constructed, reliners are a good
thing in old tires, having separation
and breaks in the fabrics and which
would not, without reinforcement.
be Serviceable. Under such circum-
stances, reliners strengthen the tires.
protect inner tubes from being pinch
ed by the fabric and often make II
possible to secure a great deal of
extra mileage.
Editors Note-The sixth and last
article in this series will contain
some very practical advice on the
repair of tires, and the proper usage
of inner tubes. 1t will appear in next