Correct way to measure backspacing
The shallower the backspace, the deeper the outside shell.
Think of it this way, the ONLY time you are moving your center section of the wheel in/out is when your are changing the axle length. If your trying to keep the wheel in the same spot, you're moving your center section in as much as you shortened the axles. End result is a deeper dish wheel.
If you are not be changing axle length, think of it as you are moving your wheel shell in/out. The further you move the shell out from the fender well, the less the backspace BUT the more it may stick out from your fenders.


