GMC Truck Forum banner

Backspacing - A new twist to an old question

694 1
Does anybody know if some companies measure backspacing differently like a size 11 shoe fits differently in a Nike vs a Reebok?

I have a problem with my tires rubbing my controller arm on the left side while on the right side the clearance is extremely tight. The shop that installed the lift, wheels and tires says my Centerlines should work with 4.5" of backspacing. RCD says for some reason the Centerlines and Eagles with 4.5" of BS don't work with their lifts.

I then came across an old street rod article on measuring backspacing that stated Weld measures backspacing from the outer edge to the mounting surface while other companies measure from the inside flange edge to the mounting surface.

If this is true, two wheels with reported 4.5" backspacing could actually be up to a .5" difference in clearance. Has anybody heard of this before? Or better yet, is anybody with a Weld wheel and a Centerline wheel willing to measure actual backspacing (measured as outermost edge of wheel to mounting surface) to compare the two?
1 - 2 of 2 Posts

· Registered
70 Posts
Discussion Starter · #2 ·
I'm still trying to resolve this issue. If anyone with an RCD 6" lift has some spare time could you give me the clearance you have between your tire and upper control arm? Also can you give the specs on your tire wheel combo?

I'm trying to collect some data and decide where to pursue a solution to my problem.

1 - 2 of 2 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.