Known-weight oar calibration
Use a known weight to measure shaft stiffness. The app combines that result with the oar dimensions to calculate Moment/Bend Factor.
Prepare the setup
In Oar Settings, select the intended oar, open Calibrate Oar stiffness, then Perform Calibration(s). The screen identifies the target. A calibration for an independent managed copy is saved to that copy.
- Connect both sensors and complete or verify sensor alignment.
- Confirm sensor positions, inboard, outboard, overall length, load/support positions and the shaft profile.
- Enter the known weight in the units shown by the app.
- Place the oar on stable supports and use Tare with no calibration load.
- Apply the weight at the recorded load point and allow readings to settle.
- Review the measured bend and calculated stiffness, then save the result with the correct oar.
Keep the supports, sensor mounts and weight in place during the measurement. Follow the setup diagram and app prompts for the selected oar type.
Use consistent reference points
The seven reference points are Blade Tip, L1 load point, S1 sensor, Button reference face, S2 sensor, L2 support point and Handle End.
Measure longitudinal positions from the blade tip toward the handle. For the illustrated fixture, the required order is Load L1 < Outboard < Support L2. The weight and supports must match the positions entered in the app.
Check the saved result is active
The test measures Cperm. Current dimensions and sensor positions adapt it into Moment/Bend Factor (N·m/°). Check the source shown in the oar’s details after saving.
Saving a new measured calibration selects that Cperm and clears both the manual Cperm and manual Moment/Bend Factor overrides. The older measurements remain available in the calibration history. If you later enable a manual value, check which source is active before recording.
For the same shaft, a measured Cperm is reusable with unchanged sensor positions and modest dimension changes. Update dimensions and positions when they change by more than 0.5 cm. Taper measurements are needed for larger changes or sensor moves greater than 2 cm; otherwise perform a new calibration for that setup. Dimensions alone cannot provide an unknown stiffness constant.