Measurement Guide
Measure twice before spokes ship once.
Wheel Builder helps calculate spoke length, but the quality of the result still depends on the hub, rim, and lacing numbers you enter.
Before ordering spokes: confirm ERD, flange diameter, center-to-flange distance, spoke count, rim offset, spoke hole diameter, and lacing pattern against manufacturer specifications or your own measurements.
Core measurements
| ERD | Effective Rim Diameter. Use the rim maker's ERD or measure with nipples seated the way the wheel will be built. |
|---|---|
| Flange diameter | Measure across opposite spoke holes, center to center. Enter left and right sides separately when they differ. |
| Center to flange | Measure from the hub centerline to each flange. Rear and disc hubs are often asymmetric. |
| Spoke count | Use the total spoke count for the wheel. The app checks whether lacing choices fit the count. |
| Cross pattern | Set left and right cross values independently for mixed lacing patterns. |
Advanced values
- Use rim offset when the spoke bed is offset from the rim centerline.
- Use spoke hole diameter when you want the spoke hole correction included.
- Use rounding modes to decide whether order length should round nearest, down, or to 2 mm increments.
Build Check states
- Ready means the app has enough believable values to calculate.
- Review means one or more values look unusual and deserve a second look.
- Needs fix means the configuration is missing data or mathematically invalid.