Calibration

What is calibration? It is a process which accurately defines the location and orientation of the fit bike relative to the camera, so that measurements taken during the fit are as accurate as possible.

The 5 points that are captured allow us to correct for pitch, yaw and roll so it doesn’t matter whether the bike or camera is level or perfectly aligned.

To begin calibration click the button at the bottom of the liveview:

Calibrate button

The calibration popup window will appear. You will use the wand to acquire specific points on the bike (or fit bike). The in-system help will guide you through the required locations.

The current point will be highlighted in Orange text, once the system has acquired that point the text becomes green and moves to the next location. The system will not collect another point within 50mm of the last one so there is no risk in holding the wand in one location for too long.

This (slightly sped-up) video illustrates the process:

And the calibration process on a wind trainer:

Here are some more hints & tips for each point:

1. Stem bolt

Stem bolt calibration point
Stem bolt calibration point

Place the tip of the wand at the centre of the headset compression cap bolt. If you are working with bars that obscure the headset cover you will need to mark the centreline of the stem (with tape) to acquire this point. If you are using a fit bike this point just needs to be in the same plane as the next two measurements.

2. Centre of saddle

Centre of saddle calibration point
Centre of saddle calibration point

Place the tip of the wand at any point along the centreline of the saddle, (use your supplied green saddle jig). If using a fit bike this can be a point on the bike that is in plane with point 1 and 3.

3. Low midline point

Low midline calibration point
Low midline calibration point

Place the wand at a point that is on the centreline of the bike, low down on the frame (bottle bosses are a good choice). The Kinect only needs to have line of sight to the pink locator triangles, it doesnt matter if the actual tip of the wand is obscured by a bottle cage or cable. If you are using a fit bike this point needs to be in plane with points 1 and 2.

4. Front pitch point

Front pitchpoint calibration point
Front pitchpoint calibration point

The pitch points are two locations of equal height (when the bike is on level ground). The wheel axles are a good choice if both can accessed - in which case you would choose the front wheel skewer for this point.

5. Rear pitch point

Rear pitchpoint calibration point
Rear pitchpoint calibration point

The system waits until the wand has been steady for 30 samples before acquiring a point. This usually only takes 1 second so it is advisable to cover the locator triangles until the wand is in position.

If you are finding that the system is not picking up a point you may need to alter the angle of the wand until the Kinect can recognise it properly.

Note that calibration is optional - you can use the system without calibrating. You may want to skip the calibration if you are coming back for a quick check of a position and you know the camera and wind trainer have not moved. Please note, that some metrics that rely on calibration and bike measurement will not be available if you don’t calibrate, and joint motion values will potentially be less accurate.

Once the process is complete click the “Finish” button.