You grease the post to keep a barrier between the two aluminum surfaces. That way when you want to move or remove the post after a while you can without the aid of a machine shop.BlackCat said:
the salsa seat post clamp should be alright correct??Brown_Teeth said:
Ye, they are considered the benchmark..chirider990 said:
while that may be true for an aluminum frame it would be different for a steel frame, although that is another story. I rather use a little grease where 'not needed' and not have to remove my seat post with a hammer when if i need to adjust it. another benifit of grease is that you dont have to twist the post to move it and you wont scratch your post.BlackCat said:
You should always always always keep a film of grease in the seatpost/frame interface regardless of it being anodized treated like the Thomson or not. Even if the seatpost won't corrode a dry inner seat tube can form corrosion around the post and make it impossible to move without some major effort. Even on carbon its many times better to use grease. Dry insertion of a carbon post can scrape off the protective clear coating on it when its forced in. The direct contact of carbon and Al actually causes the Al to react rather violently and corrode causing the post to seize. Just last week I had to destroy an EC70 to pull it out after it seized in a frame.BlackCat said:
I know this sounds like a long shot but if you are entirely certain its not the seat rail interface thats creaking and you have regreased the seatpost several times I think you might have to scratch the post as being the cause. Other than changing the seatclamp to make sure its not that maybe there's a possibility its the frame itself what creaks. I just thought about that after remembering something I saw a couple of months ago with a Giant XTC hardtail. It had an awfull squeaking on the BB area. After replacing the BB and seeing it made no difference we discovered it was actually something in the weld juctions between the tubes in the BB area that apparently caused the tubes to squeak as they flexed and slightly rubbed each other on the inside. Flushing the area in WD40 before installing the BB fixed the problem for a while.chirider990 said:
Then I bought a used frame and it came with a piece of thick paper between the bolt and nut so that the quck release and clamp wouldn't rub each other. I tried this on the bike, and sure enough it sloved the problem. Both bikes have Thomson seatposts and Salsa seat clamps btw. Hope this helps. Um, you shouldnt need to force a post to go in to begin with, if so the frame needs to be reamed so that it goes in nicely. Thus the clear coat stays on like it should and grease is not needed, it is never a good idea to put grease on carbon anyways...Hecubus said:
That would be great and all in an ideal world. Unfortunately a good portion of frames do not come with the seat tube reamed at all or the tubing isn't even sized just right. Sometimes the posts aren't right on spec either. Its nearly impossible to dry insert carbon posts in without damage on many frames. A light film of grease will not do absolutely any harm to the post. Most manufacturers recomend grease if it can protect the surface from scraping off. In carbon to aluminium interface its especially important to have an insulator in between the two. If any of the protective coating on the carbon is stripped of and there is carbon on aluminium contact the result is the carbon acts as an accelerant causing galvanic errosion. Even though the post won't corrode the inside of the seat tube is stil Al and it can corrode. Given enough time it can even damage the tube. Theres nothing more fun than removing a totally seized carbon post with a wrench after the bonding from the head clamp brakes off due to the sheer amount of force needed to twist it around to release it. Many of the early carbon tube/aluminum lug frames built failed catastrophically because of this.gunsworth said:
