Clutch sheave - connecting the dots

[WinterMountaineer]

2022 Backcountry 850, secondary clutch sheave. Belt and primary looks good.

Thoughts on what may be causing this?

 

[likkerpig]

The belt sitting in the sheaves, dots are the ribs at the bottom of the belt. Not sure if it's moisture, road salt, belt dust or whatever caught between the belt/sheave but I've never worried about it

 

[LoneViper]

Clean it up with a scotch bright pad and a little brake cleaner on a rag. Might be time for a little clutch maintaince.

 

[Dynamo^Joe]

Etched surface from salt