Ducati MONSTER 620 Manuel D'utilisation Et Entretien page 105

Warning
The shock absorber is filled with gas under pressure
and may cause severe damage if taken apart by unskilled
persons.
When carrying a passenger and luggage, set the rear
shock absorber spring to proper preload to improve
motorcycle handling and keep safe clearance from the
ground. You may find that rebound damping needs
adjusting as well. E
31