I have a new bike that has a carbon seat post. After adjusting the seat once, I noticed that the seat post was greased by the shop that put my bike together. I realize after some reading that a carbon seat post should not be greased. My question now is how do I clean it and how can I adjust the seat post to make sure that it stops slipping? It is SO annoying to go on a ride and have the seat gradually sink throughout the ride!