offset
 

can someone please explain to me what wheel offset is? most things i can figure out on my own, but this one has me stumped. is offset the placement of the center of the wheel were you bolt it to the hub, relevant to the outer edge of teh wheel? and how do you figure out what will fit where and what wont?

offset explanation
 

check this web site here.Guys are very clear.I had hard time to understand some things,till i read this article....

http://www.usacomp.com/Offset.htm

I only gave the link a glance...but just to make things clear about wheel width most steel wheels are ~1" wider overall than the measurement between the beads, while most alloys are only ~5/8" wider.

undecided,
the offset of the wheel is the distance from the ACTUAL mounting face of the wheel (where is touches the brake) to the IMAGINARY centreline of the wheel.

Backspacing is a different matter and pertains to the distance from the mounting face of the wheel to the backmost edge of the rim.

Aside from what Kaferchris said above, when you're trying to measure offset, whether you divide the ACTUAL width of the rim (measured by yourself) or the NOMINAL (5.5J, 6J, 7J etc) width by 2, the imaginary centreline is still in the same place. The ACTUAL width is only useful when calculating backspace.

ahhhh. ok. ithis all makes so much sense now. thanks guys!