[VAC] Re: what brand of tire is good?

["Dr. Gerald N. Johnson, electrical engineer" <geraldj@xxxxxxxx>]

Radial sidewalls are made to flex, bias ply sidewalls made to not flex.
If either are loaded so the sidewalls flex a lot, the sidewall life is
compromised, more rapidly in bias ply tires. For the sidewalls of bias
ply tires to flex, diagonal layers of fabric have to slide against each
other (even when glued together) and that makes heat. Radial tires have
the grain of the fabric all in one direction so they don't rub, they
just bend the fibers that are running from the bead at one side straight
out (radially) to the tread, across, and back to the other bead at the
same location. The first set of radial tires I owned changed temperature
on the highway only from the sun, not from hundreds of miles of driving.
That was never true with bias ply tires.

The maximum sway from the flexible sidewalls of radial trailer tires
shouldn't be more than an inch or two. Big tractor tires will allow at
least a couple inches side sway and when the cultivator shovels are only
6" apart that couple inches is enough to mean the difference between
dead weeds and dead crop when added to an inch or two lateral
imprecision in driving.

Gerald J.