Backspacing vs Offset question
Thread Starter
Intermediate
Joined: Aug 2012
Posts: 31
Likes: 0
Backspacing vs Offset question
I am looking at putting a set of 16x7 TT II's (VN405) on my 63 but am confused about the Offset. The wheels have a 3.75 Backspacing, but one company lists the Offset at -6mm and another has it at zero.
If both are 7 inch wheels and both have a 3.75 BS wouldn't they both have to have the same Offset? Or more practically....on a 16x7 wheel as long as the backspacing is 3.75 is there any need to be concerned about what the Offset is?
Thanks
If both are 7 inch wheels and both have a 3.75 BS wouldn't they both have to have the same Offset? Or more practically....on a 16x7 wheel as long as the backspacing is 3.75 is there any need to be concerned about what the Offset is?
Thanks
Burning Brakes
Joined: Oct 2004
Posts: 953
Likes: 27
IIRC
if the wheel is 7" wide and the backspace is 3.5", then the offset (from the center) would be 0.
if the backspace is 3.75", then the offset would be -.25" to the backside of the rim or approx -6 mm. from the center.
if the wheel is 7" wide and the backspace is 3.5", then the offset (from the center) would be 0.
if the backspace is 3.75", then the offset would be -.25" to the backside of the rim or approx -6 mm. from the center.
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,927
From: Washington Michigan
Photo below shows how wheels are measured. Offset is the dimension between the rim centerline and the wheel mounting surface, which is not affected by the size or width of the rim flange. Backspacing, on the other hand, IS affected by the width of the rim flange, so two different wheels could have the same rim width (which is measured inside-to-inside of the rim flanges) and offset dimension, but different backspacing (due to rim flange thickness).
