RUDIMENTS, pt. 1,264
(these tires tire me out)
I know this is probably hard
to believe, or to understand,
but I've spent an inordinate
amount of time over the years
thinking about tires. Yep. On
vehicles; automobiles. It's
never been a mainstay of my
thinking, but many times my
mind has gone to the subject.
I'll try and explain, and maybe
in my usual, discursive, manner
too. It's not much, but see if
you can stay with me.
-
I guess it all started long ago,
for me - my father used to
haunt the Avenel junkyards,
often buying used tires for
his vehicles. I had to think,
seeing how often he bought
used tires, at what price I
cannot recall, but let's say
(40 years ago) 15-20 bucks
each. He'd replace tires by
need, maybe 2 at a time. I
had to figure, within the
rotational and replacement
sequence that he'd get out of
the used and short-term tires,
that maybe he'd be better off
just getting new tires at a 4-tire
grouping a and not have to buy
replacements as unevenly and
as often as he'd end up doing.
-
But I think for him the thrill
came in the small and momentary
savings he'd 'think' he'd made.
Often he'd come back as if he'd
gotten one over on the tire guy
by again getting two for the
30 or 40 bucks. Hard to figure,
but the ruling pleasure principal
of everyday living often has a
form of this for everyone - for
some it's a Mulligan on the golf
course, for others it's cheating
or shoplifting. I had two friends,
Joe and Jack, who got their rocks
off buying a tire and then, in the
yard, with no power tire-equipment,
spending three or four hours with
a crowbar and tire iron, taking off
the old car tire and re-mounting
the new tire on the wheel, properly
setting it and beading it, all again
without any 'power' tool; it's OK
as a kid, doing that in a bicycle
tire, which is a cinch with a tube,
etc., but it becomes a different
story with a full-size car rim;
wheel and tire both take struggle.
-
My approach to the actual 'physical
aspect of tires and the work needed,
is not what I'm talking of (or, writing,
of). It was always more about the
physics, or the dynamics of what
made tires wear. I figured all the
tire and rubber companies had
roomfuls of scientific types doing
the same thinking as me. What
exactly made a tire wear down?
What dynamics were at play. As I
studied the subject, I realized that
there are numerous variations of
compounds, treads, sidewalls and
loads. That was obvious. Any of 30
different compounds of the rubber
in use could lead (steer) to any of
an assortment of adhesion and wear
factors, dependent on price, quality,
freshness, dry rot,(age) and eventual
breakdown and splitting of the bands
belts and sidewalls of the tire. Heat
and compression took their own tolls.
What mostly interested me was the
dynamics of the tire, on the road. I'd
sit and muse about how and what
contact a 'rolling' tire, in continuous
motion, (forward and at speed) had.
I'd figure it was not much, or for a
faint instant. The roll of the tire,
forward, made for a limited and
essentially frictionless contact patch?
Did it not. What effect than had the
other factors - heat, the stress of
turning, and speed have? How was
any of that taken into consideration
and factored in? If a contact patch,
even slight, it repeated in the constant
roll of the tire upon the road, to what
steady amount does that accumulate.
A rainy day then allows for no 'friction'
or much less? The factor of the weight
of the vehicle, steaming along on a
dry roadway, with the stress of steer
and turn, aligned with heat, makes
the difference? Does a 'new' tire, with
its rubber, wear less quickly, or more,
than older tires. Alignment, wobble,
braking, and basic steering, what do
they add to nay of these factors? At
some point is an equilibrium reached?
-
Yes, yes, I'm boring you, and it all
could go on, but I wanted to show the
process involved. I had a friend, for a
long time, who was an 'accident-scene
investigation' policeman; always at the
ready with tape measure and micrometer
and all those items need to measure skid,
impact, and resultant crash momentum.
Tire tread, in thirty-seconds of an inch.
Sideways momentum; speed, erratic
driving. Tires. Tires. Always tires.
-
One time, in Princeton, a long time back,
the place where now are stores and an
Italian deli called D'Angelo's was once
an old parking lot. It had a barbarous
reverse-tire spike strip to prevent people
from backing through, or exiting out
of the entrance. It was relentless in its
automatic zeal to take out two tires at
a time. Suffer those who got caught by
it. Instant flats. Now the cops can stop
pursuit by halting the fleeing auto with
the same spike-strip idea, simply placed
along the roadway where the perp is
expected next. Too bad on that count;
tires again. Security and police, etc.,
I have seen, with puncture-less tires,
unable to be compromised by bullet,
shot, or cannon. It's all tires, even if
the car is electric.
-
I decided, somewhere along the way,
that - much like life - tire wear is the
result of a cumulative scraping. It builds
upon itself, and it's not as if a person is
scraping a piece of rubber along the
ground, (though it is), but more that
the accumulation of all those rolling
and momentary contacts, even with
the rolling of the tire making the
moment of contact trivial, the wear
accumulates, the treads wear down,
and the tire, soon enough, is scraped
away to nothing. Now there's a cheery
thought for sure.
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