Wheel Tech

Offset & Backspace

The rim backspace is the distance from the back edge of the rim to the hub mounting surface. To determine the rim backspace:

  • Position the rim face down.
  • Lay a straight-edge across the back of the rim. Measure the distance from the straight-edge to the rim's hub mounting surface.

The rim offset is the distance from its hub mounting surface to the centerline of the wheel. To determine rim offset:

  • Position the rim on a flat surface and measure its overall width.
  • Divide the overall width by two, then subtract this result from the backspace value.

Offset = Backspace - (Rim Width / 2)

The offset of a rim can be one of three settings:

Zero offset
The hub mounting surface is even with the centerline of the rim.
Positive offset
The hub mounting surface is toward the front or wheel side of the wheel. Positive offset wheels are generally found on front-wheel drive cars.
Negative offset
The hub mounting surface is toward the back or brake side of the wheel's centerline. "Deep dish" wheels are typically negative offset.