Your bike is shipped with the standard wheel circumference already loaded. If you would like to use a specific circumference for your setup ( like if you got a different set of tires ), just follow this procedure:
- Fill the tires to your preferred pressure (while staying at least 15% below the maximum pressure).
- Place a mark on your tire using a marker or chalk, and line this mark with another mark on the floor.
- Mount your bike so that your weight compresses the tire as it would during riding.
- Slowly move in a straight line until you see that the mark on your tire has completed a full rotation.
- Stop and mark the floor according to the mark on your tire.
- Measure the distance on the floor from the first mark to the second mark. This distance can be compared to the distance in your LCD settings.
And if you want to go back to the original measurement just confirm it here