Is there any way to measure the offset of a wheel?

HwyStar · 07-31-2002, 02:14 PM

I'm looking to buy some wheels and need to find out the offset for these wheels. How do we measure the offset?

The Dude · 07-31-2002, 02:26 PM

Backspacing is the distance from the mounting pad to the inside edge of the rim.

Offset is the distance from the mounting pad to the center line of the wheel.

Zero offset means the mounting pad is right on the center line.
Positive offset means the mounting pad is closer to the outside edge of the wheel.
Negative offset means the mounting pad is colser to the inside edge of the rim.

I think it would be tricky for a DIY-er to measure offset because the center line of the wheel is sometimes a point floating in space.

SWCDuke · 07-31-2002, 09:14 PM

It's easy. Lay the wheel, with or without a tire mounted outside face down on a flat surface and lay a straight edge across the "top". Measure the overall width between the straight edge and surface and call this dimension "A".

Now measure from the straight edge to the wheel mounting plane and call this "B".

Offset = B - A/2, and this will yield the correct algebaic sign.

Duke