This online calculator will help you determine the mechanical values and measurements for your frame tubes. All entries should be in millimeters. Don't forget to add a value to the simple & torsional deflection boxes!

16mm	5/8"
19mm	3/4"
25.4mm	1"
28.6mm	1 - 1/8"
31.8mm	1 - 1/4"
35mm	1 3/8"
38mm	1 - 1/2"
42mm	1 - 5/8"
44mm	1 - 3/4"
50.8mm	2"