I read the manual that came with my bike, Trek 4500 if it even matters.
It advises to apply some grease to the seatpost yearly I believe. Well, I have only had this bike for about 2 weeks I think, but I adjusted it to the exact right place I wanted it, and about 5 miles into every ride, I notice it has lowered about an inch, and pedaling gets very inefficient. The frame is the correct size for me, and the seatpost isn't extremely far out of the frame, there is probably about 6-7" rough estimate showing when it is in the right place. I noticed there seems to be a lot of grease on the seatpost. Would it be ok to wipe some of it off, to maybe avoid this problem? Is there such a thing as too much grease on the seatpost? I already made sure the quick release on the seatpost is closing securely, it seems to be about as tight as it can be without being too tight, and stripping it out or something.