The perfect set of wheels is an essential element of any classic car build, but choosing wheels isn't always as easy as it might seem. There are many technical variables that must be considered, including bolt pattern, diameter, width, backspacing, and offset. Once you've established the wheel specs you need, you'll have to shop for an appropriate set of wheels with an appealing design and finish. In this article, we'll provide some info and diagrams to help you answer the question "what are wheel backspacing and offset?"