I serviced the jockey wheels on the rear derailleur for the first time and found something curious. The jockey wheel closest to the center, the bearing sleeve seems like it was made of ceramic. Is this standard?
I thought ceramic parts were exotic. I cleaned them out throughly and even with light machine oil, while better then before cleaning, did not spin all that freely. I dabbed on a bit of grease and now they are sluggish.
The outer jockey wheel in comparison, before servicing was free spinning. The sleeve was made out of metal, and used "dry" chain oil.