I just got home after some hub trouble. After feeling the cranks skip, like when the a lock ring is loose, i took a look at my wheel. I have been riding it hard for about for months since installing a new cog. I figured that whatever happened, I could just flip the wheel around and use my other cog. I rode slowly home, because I didn't want to flip the wheel while it was covered in grime, it is really slushy here. For a little while I felt a slight vibration in the wheel. When I got home, the slush on the NONdrive side of the hub was completely orange. I'll take it apart after it melts away, but I dont know what happened. These are sealed hubs.