## Measuring Pulley Diameters

Measuring the pulley diameter of belt-driven accessories can be difficult. Measure the diameter where the belt rides on the pulley, NOT the pulley's outside diameter. Try to be as accurate as possible.

Before you enter the pulley diameter in the diameter box, you must first convert the fraction to a decimal. If the pulley diameter of the crankshaft pulley was 7 7/8”, you should find 7/8 in the chart below to get 0.8750” as a decimal equivalent, then enter 7.875 in the diameter box. The conversion chart below shows the most common fractions and their decimal equivalents. Metric measurements are supported can be entered directly.

 Fraction Decimal Equivalent 1/16 0.0625 1/8 0.1250 3/16 0.1875 1/4 0.2500 5/16 0.3125 3/8 0.3750 7/16 0.4375 1/2 0.5000 9/16 0.5625 5/8 0.6250 11/16 0.6875 3/4 0.7500 13/16 0.8125 7/8 0.8750 15/16 0.9375

After measuring the pulley diameters and converting them to a decimal, select the pulley button at the top of the screen. This will open the Belt-Driven Accessories Pulley Diameters box. Click the button with the pulley name on it to enter the diameter.