spridgets
[Top] [All Lists]

Wheel Dimensions

To: Spridget List <spridgets@autox.team.net>
Subject: Wheel Dimensions
Date: Sun, 16 Jul 2000 22:54:39 -0400
Interested Listers:

I have been searching for a set of wheels for my ' 67 Midget vintage race 
car for a while now. I use 5.5" wide Western alloys with Hoosier A70s when 
I race with HSR. I have begun to race with VDCA, a new group that is 
much more concerned with period authenticity and to comply with their rules, I 
can only use street radials on a 5.0 " wide wheel. Most of my fellow 
vintage racers use the Panasport Minilite replicas but I want something 
different and cheaper. In my search, I've looked at wheels from all the
stock Spridgets, Chevy Vega, and BMW 2002 and thought some of you might be
interested in my findings.

Assuming we are only talking about 13", four stud, 4.0" bolt circle wheels, 
all the non Spridget wheels seem to have problems. Not insurmountable, but 
challenging, nonetheless. The two problems are center hole size and rear 
offset. The Spridget has a rather large "cone" on the front hub and rear axle 
"mushroom" on the flange that have to fit inside the center hole of the
wheel in order for the 
wheel to sit flush against the front hub flange and the rear drum. If the
center hole on the wheel is not large enough, the wheel is not brought up
tight to the mating surface by the wheel nuts, it wobbles and you have
serious problems. A 1/4" thick wheel spacer will solve this problem, but
the spacer 
may throw the wheel/tire too far out so that it 
interferes with the fender on a square wheel arch car. It may also cause 
the studs to be too short for sufficient thread engagement with the lug nut. 
This interference shouldn't be a problem on round wheel arch cars.

Another detail to consider is the configuration of the lug nuts and the
wheels. Spridget wheels and nuts have a different bevel than American
wheels. Some alloys use shoulder nuts and washers so there isn't a problem.
I installed  7/16 " studs from Pep Boys on the race car and had to use
American nuts to fit them. When I temporarily used Rostyle wheels, the
bevel of the American nut did not match the bevel on the British wheel. I
had to take 16 stock chrome lugnuts, drill the right size hole all the away
through, and tap them for the 7/16 x 20 studs. Also make sure the studs are
long enough to fully engage the nuts. With the spacers, I have to convert
again from the 1 1/2 " long studs to the 2 1/8" studs and use open nuts.  

The other problem in non-Spridget wheels is the rear offset. As you can 
tell by looking at the following dimensions for the non-Spridget wheels,
the offsets can be quite different than stock. If the offset varies from
stock too much, you 
once again have clearance problems with the sheet metal. The smaller the 
rear offset dimension, the further the wheel protrudes towards the outside
of the 
car and the inside of the fender. I have found that any wheel with a rear
offset between the stock 3.0" 
and about 4 3/8 " fits fine on a SWA car.

I have determined that Vega wheels won't work on my SWA car, so they are 
available if anybody wants them for a RWA car.The BMW 2002 steel wheels 
look like they will work fine. They are 100 mm bolt circle but otherwise
seem to 
fit. Of course, I will have them tested for cracks and trueness before I 
sandblast and paint them. I hope the information below helps and you don't 
have to accumulate all the wheels I have before you finally find something 
that fits.

STYLE   WIDTH   REAR OFFSET
                
BUGEYE  ?       ?
SPRIDGET, STEEL, SOLID  3 ½     3
SPRIDGET, WIRE  4       3
ROSTYLE, EARLY, 8 SLOTS         4 ½     3 3/8
ROSTYLE, LATE, 4 SPOKES         4 ½     3 3/8
VEGA, STEEL     5       2 5/8
VEGA,GT, STEEL  6       ?
BMW 2002, STEEL         5       3 11/16
WESTERN, ALLOY  5 ½     4 3/8


Regards,

Bob Spruck
Sharpsburg, GA
' 67 Midget Vintage Racer
' '72 Midget Weekend Car
4 parts cars in the woods

<Prev in Thread] Current Thread [Next in Thread>