<VV> Re: Supply of 13" Tire Question

[NOSVAIR@aol.com]

In a message dated 5/26/2004 12:15:19 PM Eastern Daylight Time, 
virtualvairs-request@corvair.org writes:

> 
> >>Kelly Springfield still makes a 165/80R13 and it's a whitewall...
> >
> >This is an awfully small tire to put on a Corvair, let alone a
> >late-model.
> 
> Isn't it the modern equivalent of the standard size - or as close to it as
> you can get (only 20% lower profile than original)??
> 
> Or were they wider originally? Lots of British and European cars have these
> as standard.
> 
> Cheers
> 
> Alan
> 
> 

Alan,
  I took measurements from 2 tires (EM and LM) known as originals from the 
factory.  The first is a US Royal 650-13" Safety 8 (our Canadian cars received 
the equivalent from our US Rubber subsiduary Dominion Royal) with a diameter 
exactly as Bruce Shugg says.  24.58".  This was all new low profile bias ply 
tire technology when introduced on the Corvair since Ed Cole had long known that 
common taller profile tires didn't perform well with rear engine/rear drive 
engineering.  The confusion with matching radials to exact what came originally 
really lies in the amount of tread width.  The 650-13" original has only 4 
1/8" of tread width and here is where a modern 165-13" radial comes closest to 
matching original...tread width!  So in stating a 165-80-13" is the modern equ
ivalent is in a sense correct if it weren't for the substancially lower rolling 
diameter.   The problem is that that size of radial tire is better suited to a 
4 1/2" rim width.  The LM 700-13" Uniroyal Laredo that graced the last of the 
Corvairs had increased the tread width to 4 3/4".  The tread width here would 
be closest to a 175 80 series 13" radial but again a tad small for the 
Corvairs 5 1/2" rim width.  Most everything offered in tires by American car makers 
by the late '60's had a stepped down profile while tire widths got way crazy. 
Uniroyal Tire Paws come to mind. This was sort of a natural evolution just 
before the offering of radials as optional equipment on high end American made 
cars around 1972.  

Bruce Webster
'60 500 Sedan 
'61 700 Coupe 
'64 900 Coupe