Ducati ST3 Owner's Manual page 147

To set the rear brake pedal, loosen check nut (4).
6
Turn pedal travel adjusting screw (5) until pedal is in the
7
desired position.
Tighten check nut (4).
Work pedal by hand to make sure it has 1.5 - 2 mm free
play before brake begins to bite.
If not so, set the length of cylinder linkage as follows.
Loosen the check nut (6) on cylinder linkage.
Tighten linkage into fork (7) to increase play, or unscrew
E linkage to reduce it.
Tighten check nut (6) and check pedal free play again.
5
4
fig. 26
38