Wheel Offset & Backspacing Diagram - Rim Width, Offset (C) & Back-Space (B)

This document is a labeled cross-section diagram explaining how to measure key wheel (rim) dimensions. The drawing shows a wheel in cross-section viewed from the back side, with red dimension arrows overlaid. The full 'Rim width' spans the top of the drawing and is divided into two equal halves, each labeled 'A' — the accompanying text states that Dimension A is half the rim-width. Dimension C, drawn from the wheel's centre line (marked CL) to the mounting/bolt face, is identified as the OFFSET of the wheel, defined as the difference between the centre line of the wheel and the bolt face. Dimension B, drawn from the bolt face to the back edge of the rim, is identified as the Back-Space. The diagram is credited 'Copyrite C D Clubbe 2003'. A reader can learn how offset, backspacing, and rim width relate to one another geometrically and where each measurement is taken on a wheel's cross-section, which is useful when selecting aftermarket wheels or comparing wheel fitment specifications. The diagram is generic and does not reference any specific vehicle make, model, or year.