Re: Hoosier bias ply tire sidewall flex

["Smith, Kirby A" <kirby.a.smith@lmco.com>]

In the mid '60s, race tires were all bias ply, low profile, and reverse
molded (and x-rayed).  They had much less sidewall flexure than radial
tires of the day, and were at least comparable in that regard with
today's radial performance tires of the same profile.  

I used to use Firestone rain race tires on my Corvair for street use.
(Their tread pattern was similar to many performance street tires of
today.)  Although they had only 5/32 inch tread to start, and a
significantly softer compound, they lasted as long (to the 2/32 inch
point) as the contemporary much squirmier Firestone Wide Ovals that
started with 11/32s.  (About 15 kmiles each.)  And they cost the same!
And they were vastly better in the rain.

The bias ply Goodyear racing slicks I used for the track were similar in
stiffness (trolling for comments from Akron).  I think one would be hard
pressed to find a car more sensitive to undesirable sidewall flex on the
rear tires than a Corvair.

         ....  Kirby  (kirby.a.smith@lmco.com)
                   New Hampshire, USA
                      2 X 1988 90q
                 (& 1 partly assembled 1966 Corsa)