How To Measure?

The widest point of your tire and wheel combination is usually the outside diameter of the tire sidewall. Using a ruler with the straight edge flush with the face of the tire, measure the gap between the outer face of the tire to the inside lip of the fender as shown in the diagram. This will determine the thickness of the spacer you will need.

5MM = 0.197 INCH / 8MM = 0.313 INCH
10MM = 0.393 INCH / 12MM = 0.473 INCH
15MM = 0.590 INCH / 20MM = 0.787 INCH
25MM = 0.983 INCH