Step 3: Front Derailleur Limit Screw Settings
If the screws are not marked, you will have to test them to figure out which is which. Shift to the inner front chainring. Select one of the screws and turn it clockwise then counter-clockwise. If the derailleur moves then this is the “L” screw. If it does not; test the other screw. The screw that does not move the derailleur is the “H” screw. Make note of which is which.