Originally Posted by Otto Skorzeny
Bztguy,

Offset = distance from the mounting surface of the wheel to the centerline of the wheel. Farther outboard is (+) offset, inboard is (-) offset. Centerline directly over mounting surface is (0) offset.

Backspace = distance from inboard edge of the rim to the mounting surface of the wheel.

Otto: To clarify, Positive offset moves the mounting surface outboard relative to the centerline and will move the wheel centerline inboard and vise versa. See Les Schwab website for illustration.

1951 3800 1-ton
"Earning its keep from the get-go"
In the DITY Gallery
1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971.