View Single Post
Old 03-20-2024, 08:30 PM   #9
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,521
Re: -20mm offset rims on 8 lug

Quote:
Originally Posted by Dashman View Post
The back spacing and the offset don't correlate. If the wheel is 8" wide and the back spacing is 3.71", then there is 0.29" to the centerline. 0.29" is 7.36mm, or -7mm offset, not -20mm. The conversion is 1"/25.4mm or 25.4mm/1" depending on which units you want. Those are like factory wheels. It's the 12.5" section width that may cause some interference while turning depending on your lift. That tire will be out (12.5-8)/2 or 2.25" per side. You could actually measure out from Wheel Mounting Surface (8-3.71) +2.25 = 6.54" to get an approximate edge of tire section.
But an 8 inch wheel is measured from bead to bead. It’s actually 9 inches wide from lip to lip. Backspacing and offset are derived from the measure of wheel mounting surface to the lip.
His -20 mm is spot on.
geezer#99 is offline   Reply With Quote