Re: [T3] Wheel sizes

["Jim Adney" <jadney@vwtype3.org>]

On 29 Mar 00, at 18:02, Mark Healey (formerly AKA Edmond Dantes) wrote:

> A while ago I asked how one tells the proper wheel.  Someone replied that
> between two lug holes would be 15x41/2J.  The spare in the square I just bought
> has 4Jx15, the one that I took off a junked square has 41/2Jx15, the one I took
> of the T3 Ghia I junked has 51/2x15 . Aside from the scrambling of the order of
> the numbers how much difference does this make.

These could all be real VW wheels, except maybe the 5-1/2". I'm 
not sure if VW ever sold that size on one of their cars, so it may be 
aftermarket or from a late beetle. If these are all 4-bolt wheels then 
only the 4-1/2 could actually be a type 3 wheel. 

OE VW wheels have VW stamped into them also, along with the 
month and year, the Offset, dia, profile, and width.

If it is a type 3 wheel it will say 15 J 4-1/2 AND 42 somewhere. If it 
has an number other than 42 it is a beetle wheel.

For every tire size the tire manufacturer has a recommended range 
of rim widths that will work correctly with this tire. 4-1/2 is the right 
width for a 165 tire while 4 is correct for a 155 tire. A 5-1/2 rim 
would probably be good for a 185 or 195 tire, but way too wide for a 
165.

> What are these numbers measurements of anyway?

4-1/2 is the inside measurement (in inches between the rims) that 
tell how far apart the bead of the tire will be allowed to spread.

J is a designation of a certain kind of rim profile. J rims were 
introduced in about 66 to use with tubeless tires and have the 
"hump" just inboard of the bead seating area on each side. Non-J 
rims should always be used with tubes, otherwise there is danger 
of sudden loss of inflation on hard cornering.

15 is the diameter of the rim where the bead seats.

42 is the Offset (from the rim centerline to the mounting plane) in 
mm.

[It's possible that I'm not remembering the 42 correctly.... Could it 
be 46 or 47 for a type 3? I know it is forty-something. See the 
Bentley manual for the right #. Beetles were usually thirty 
something, and they varied a lot.] 

Hmmmm, starting to sound like some kind of soap opera. ;-)

-
Jim Adney
jadney@vwtype3.org
Madison, WI 53711-3054

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