Calibration is the most important part of installation. Vololights needs to learn its position with respective to ground. You will need a friend to help you with this.
1. Make sure the bike is upright in riding position
2. Make sure the the bike is on a flat surface
3. After the start up sequence is completed, introduce the magnet. Remove the magnet as soon as both the top and bottom LEDs flash once- keep the bike still in the riding position until the bottom flashes with three quick flash followed by three slower flash
See video for example