Multiply the result by 2 and subtract that number from the outside rim measurement. This is the diameter of the actual spoke holes in the hub flange. The default value of 2.5 mm works fine for most hubs. Hub spoke hole diameters range from 2.0 mm to 3.0 mm. This is the number of times a spoke crosses another spoke during its travel from the hub to the rim.
More crosses create a longer spoke, more tangent spoke, and more torsionally efficient wheel.
Less crosses require a shorter spoke, but is less torsionally efficient. For this reason, most torsional wheels, like rear wheels and disk brake wheels, use 3 and 4 cross. Traditional spokes are measured from the inside edge of the elbow to the end of the threads. Inc. Duplication of anything on these pages is prohibited other than by special permission from United Bicycle Institute or its representatives. Photography by Dave Hawkins, web page design by Dana Bandy.