My rear SC2 is peeling on the leading edge of the tread, so I reckon the preload is too soft.
It's got DDC, but I don't know what settings/dials I have on the rear shock. Ideas anyone?
Tyre pressures both checked as okay? Road or Track riding?
You should only change the preload to set the suspension 'sag' for your weight, have you already set the sag for your weight?
If yes, then use the DDC settings on the dashboard to change the compression and rebound for the rear - check the owners manual to understand how to access access the DDC menu. If you don't have an owners manual, you can download one for free on the Motorrad website for your bike.
If you've never set the sag for your weight, get a friend to help you measure the settings, adjust the preload until you are within the sag limits and then use the DDC menu to stiffen the rear with compression and rebound. Read this thread and make sure that the bike ignition is ON whilst you perform the changes to the preload.