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Discussion Starter · #1 ·
I just built up a new salsa bandito and put on a thompson post. after the first 5 rides it started creeking. so i regreased the post. i then rode 2 more times and it creeked again. so i regreased. is there anyway to get rid of the stupid creeking for good. i know it is not the rails of the seat because it creeks in my repair stand when i am lubing the chain. any ideas.
 

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high plains drifter
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is the frame new

after about a year or two my al frames start to creak thats when I know only bad things to come .edit; Iam sorry you said it was new ,disregard
 

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BlackCat said:
Why are you greasing it in the first place?
There is no friction when in use and clamped properly.
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.
 

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Seat post clamp to seat post problem, make sure you are running the clamp that is OK for thomsons. The Thomsons do flex so there is offset on the seat clamp needed, its in the manual, I like mine but I do creak too cause I have a POS seat clamp.
 

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Brown_Teeth said:
Seat post clamp to seat post problem, make sure you are running the clamp that is OK for thomsons. The Thomsons do flex so there is offset on the seat clamp needed, its in the manual, I like mine but I do creak too cause I have a POS seat clamp.
the salsa seat post clamp should be alright correct??
 

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As long as the clamp has an offset on the top of the clamp, the thompson seatpost requires some fore aft flex given its exotic construction. It was in the manual that came with the post, if you didn't get one go to their site or email them. My problem is the wrong clamp that allows any grain of sand to get caught and chirp. I'm not familar with the salsa clamp, g/l!
 

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Lotusfinger said:
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.
If you keep the raw aluminum seatpost untouched for a few years, then maybe. The Thompson is far from having a raw aluminum finish.
 

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BlackCat said:
If you keep the raw aluminum seatpost untouched for a few years, then maybe. The Thompson is far from having a raw aluminum finish.
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.
 

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BlackCat said:
If you keep the raw aluminum seatpost untouched for a few years, then maybe. The Thompson is far from having a raw aluminum finish.
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.
 

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chirider990 said:
I just built up a new salsa bandito and put on a thompson post. after the first 5 rides it started creeking. so i regreased the post. i then rode 2 more times and it creeked again. so i regreased. is there anyway to get rid of the stupid creeking for good. i know it is not the rails of the seat because it creeks in my repair stand when i am lubing the chain. any ideas.
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.
 

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My money goes to some sort of grit such as sand or mud gettin in there. Take off your clamp and post then degrease both of them and the inside of your frame. then wipe them off, regrease and you should be good to go. Has worked for every creak prob Ive had and many others that have brought their bikes to me. Sometimes it will even happen with cranks and stems, same procces will solve 99% of creak issues.
 

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Try this

I had the same problem and parted my bike out completely and regreased every single bolt. The freaking creeking was still there, and it drove my riding friends craze. :D 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.
 

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Hecubus said:
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.
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...
 

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ummm... how about the BASICS?

are your seat clamp bolts torqued to 48 in/lbs? this is the cause of most Thomson-related issues, insufficient torque and/or improper torquing sequence.

ya gotta remember, Thomson are PRECISION MACHINISTS and their parts require equal attention to detail.
 

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gunsworth said:
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...
Amen. These mechanics here grease up the post with some bearing grease then hammer it in.
 

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gunsworth said:
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...
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.

Heh, did a quick google search on the subject and found quite a bit of info on the subject. This was a pretty interesting (the F-16 part) comment by some engineer:

"Carbon Fiber does indeed attack aluminum
VORACIOUSLY if any hint of moisture gets into
the matrix. All the metal parts on the F-16 fighter that
contact CF are Stainless Steel, Passivated too if I am not
mistaken to more closely match the electronegativity value of the
two materials."
 
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