<VV> Big Rims

[Sethracer at aol.com]

In a message dated 10/3/2006 11:58:49 AM Pacific Daylight Time, _Padgett_ 
(mailto:Padgett at shaw.ca)  writes:

Hokey  folks, I know of at least three different backspacing families used 
in GM  5x4 3/4 (aka 5x120.7).
1) The early drum brake cars (maximum  backspacing)
2) Mid-70's disk brake cars (mid)
3) Late models  (least)





That is only partially correct. The latest GM cars with the 5 on 4.75  
(93-2002 Camarobirds and C4/C5/C6 Vettes) have a huge backspace - used  to clear 
huge brakes and calipers. Some wheels as much as seven inches from  the mounting 
surface to the inner wheel lip. The common Camaro rims of the 70's  had about 
6-8mm offset. The 14 x 7 works out to around 4" backspace. The early  wheels, 
the 14's and 15's of the 1950s were pretty narrow wheels to begin with -  a 14 
x 6 was wide! I imagine their backspacing was less than the Camaro wheels.  
But my 1955 Chevy experience was way back.  
 
 
Oh yeah - GM used two different FWD 5-bolt patterns - 5 on 100mm X-body and  
many derivatives, and 5 on 115mm used on mid-size and larger for 1985-on. Some 
 models, the Chevy Celebrity comes to mind, used both patterns at the same 
time.  Usually only one pattern per car, though! - Seth