How is Backspacing of a Trailer Wheel Determined

Question:

how do we measure the backspacing

asked by: Roy

Expert Reply:

Backspacing is the distance from the mounting surface to the outer edge of the wheel. You can use a straight edge and a ruler to determine this or if you know the listed width of the wheel and the offset you can determine it from that.

Assuming it's a trailer wheel with a zero offset (they nearly all are) you'd take the overall width of the wheel, add 1 inch for flange lip, and then divide by two to get the backspacing.

expert reply by: Jameson C