Ducati Monster 1200 Owner's Manual page 259

MINIMUM TREAD DEPTH
Measure tread depth (S) at the point where tread is
most worn down: It should not be less than 2 mm,
and in any case not less than the legal limit.
Important
Visually inspect the tires at regular intervals for
cracks and cuts, especially on sidewalls, bulges or
large spots which are indicative of internal damage.
Replace them if badly damaged. Remove any stones
or other foreign bodies caught in the tread.
S
Fig 186
257