Thanks to Derek for this

Sonic Belt Tension - Ducati update
The following service bulletin has been issued by Ducati North America. Note that the specs are now the same for all models 2V and 4V. There are a few omissions from the list - 748 and ST4s, but I would think that's just an oversight.

All previous and new model Ducati’s requiring belt tensioning now will be standardized to the below specifications.

IMPORTANT: When checking and adjusting timing belt tension at the recommended scheduled maintenance intervals, if tension reading is less than 70 Hz (minimum allowed value on all Ducati motorcycles), reset belt tension as follows:

Refer to the appropriate shop manuals for cam timing procedure and belt tension setup, then reset to the below tensions for service.

Model
Belt tension spec for new belts upon replacement
Belt tension adjustment settings for used belts when inspected value is determined to be 70 Hz or less

All models:
Streetfighter, 1198, 1098, 1098R 999, 998, 996, 916, 848, 749, M1100, MS4, MS4R, MS4RS, ST4, SC, ST3, ST2, SS1000 HYM 1100, MTS 1100,MTS 1000, MS2R 1000, M696, MS2R 800, M620, M400, M695, SS800, MTS 620

New Belts:
110 Hz +/- 5, Horizontal and Vertical *

Used Belts:
90-100 Hz +/- 5, Horizontal and Vertical *

* Please note, these values may be inaccurate on previous Ducati Technical Data posters and service manuals. Data listed above should be considered the new standard and supersedes all previous bulletins and documentation. Please print and post this bulletin to be displayed with the most current Ducati service poster.

Sincerely,

Ducati North America
Service Department