To build a wheel you must measure your hub and rim to determine spoke length. The better your measurements, the more accurate the spoke length prediction. Here’s a tool to make that easier.

Thanks to Adrian Emilsen I was reminded how helpful a height gauge is. I’ve got one you should consider—iGaging’s precision digital tool. Here’s one in use in Adrian’s workshop in Western Australia.

The IP54 tool is a great choice. Features:

• Travel range: 0-6” (150mm)
• Resolution: 0.0005″ (0.01mm)
• Accuracy +/-0.001″ (+/-0.03mm)
• Repeatability: 0.0005″ (0.01mm)
• Large LCD Display
• Solid aluminum base with strong magnets embedded
• Stainless steel beam
• Powered by a single battery which lasts about 1 year with normal use (a second spare battery is included)
• Controls: Zero reset, On/Off, inch/mm/fraction conversion, Hold, Absolute.
• WATER / OIL RESISTANT – Protection Classification IP54 (light splashes)

We ship it with instructions and a hub stand—a one pound slug of polished steel, 76mm diameter x 13mm depth, with a 12mm center hole. Any QR or thru axle hub will sit still so you can adjust the measuring beam.

Here on an American Classic disk rear hub.

For hub width determination, refer to the image below. First set the sliding beam on the base and press zero. Raise it to the center of the next flange (A) and note the number. Then raise to the second flange (B) and again note the number. Finally raise it to the axle end (C). Note the number.

Right hub width (center-to-flange) = C/2 – A

Left hub width (center-to-flange) = C/2 – (C-B)

Easier than fumbling with a vernier.

A height gauge also assists rim measurement. Establish width, bead seat location, and hole offset.

Rim hole position.

Add a height gauge to your workshop!