Rich I am not going to agree or disagree with the points you make - but I would correct one point.
You state that tires are hand made. This was largely true in the
earlier times, but most current tires made in mass production
quantities are made with computer controlled or robotic equipment
to much tighter tolerances than those of your and my times.
While hand made tires made in small batches can be made to tight
tolerances (I recall favorably the Goodyear Race tires we had in
the late 1970's and early 1980's), the tendency of most hand built
tires is to exhibit more variability. This is also true of tires
made in small batches (maybe 50 tires or less) due to low demand
such as our odd sizes.
You may blame this on operator variability /inconsistencies, or learning curve because the last time a particular tire size was made was a year or more back, or raw materials issues (each tire size will have a unique set of raw material configuration / widths, etc), or simply the hand build process.
This is particularly significant on belted tires - either radial
or the old style bias belted tires. In the 1970's when bias belted
tires came out there wee a number of recalls due to belting not
being straight. The effect of belt inconsistency was doubly bad -
it caused the tire to tend to wander more - and because the belts
(particularly steel) added more weight at the maximum diameter of
the tire, any imbalance due to the belt had much more effect. I
experienced this first hand on my 1968 Plymouth Sport Satellite.
This was the beginning of the urgent need for more attention to
improve product consistency and tighter tolerances.
High volume mass produced tires these days are almost always
built with computer controlled equipment and / or robotic devices
which produce a much more consistent product - both from tire to
tire and within an individual tire (minimal weights to balance,
Specialty tires such as our reproduction tires and odd sizes made in small batches are probably still mostly hand built - so your point about hand built tires is in my opinion valid, but comparing those to your Michelins or Hankooks made on more precision computer controlled equipment is not realistic.
One additional point I will make is that the Coker Classic I have
(2002 vintage NoS) was made in the old style clamshell mold. The
Michelin NoS H78R14 I have were made in newer style segmented
molds. The difference is the segmented molds are much more
friendly to the manufacture of steel belted radials since they
require less distortion of the tire and its belts in the uncured
state going into or coming out of a fixed circumference mold.
Most, but not all of the mass produced tires use the segmented molds - I believe my most recent Cooper Trendsetter in 235/75R15 still used the clamshell mold.
On 5/10/2018 2:10 AM, 'Rich Barber' c300@xxxxxxx [Chrysler300] wrote:
Posted by: EMATC <millserat@xxxxxxxxxxxxx>
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