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Technical & Reference Section => Tech and Restoration => Topic started by: cd on September 13, 2006, 10:14 PM
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Hi,
I have a sticky seat post!!
I have heated the join, WD40d it, forced it as much as possible and I still can't get the seat post out. Does anyone have any bright ideas?? I don't wnat to break anythting thus I havn't wacked anything yet....
cd
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try tightening an old stem inside...then use hammer too tap it out.
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steel when rusty bonds like welding, try crush the seatpost in a vice & break out of the frame
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try drilling a hole throught the diameter of the seatpost and inserting a metal bar and twist that , i have read posts on here avising filling the seatube with caustic soda (be fooking careful when doing this )cause you could damage the finish or yourself
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You could try diesel, pour it along the edge of the frame where the seatpost goes in and around the slit in the frame and try giving the seat post a good whack with a big hammer to break the "join", I kid you not on this bit! Whacking it with a hammer will usually break the join between the two metals as Weston says, the rust acts like a weld to a degree.
Marty :daumenhoch:
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Thanks to all for the ideas. The seatpost is alloy so the rust bond won't be so strong as steel / steel. I very much like the idea of dilling a hole in the old post, good idea to get that bit of extra leverage. I'll try:
0) Diesel
1) some gentle whacking
2) the hole
3) dipping in oxalic acid
4) some more whacking
The frame I'm restoring has been pretty abused with everything over tightened. The head set was tightened so much that the bearing cases were crushed and had fallen apart! I had to soak the frame in oxalic for 5 days and then still have two people hold down the frame while I had to use a breaker bar extesion to undo the lock nut which over years of abuse was not so much heaxgonal but round. :knuppel2: The seat post is the very last attachment!
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we use these things at work called easyouts which come in different sizes.they are slightly tapered with a reverse broad thread which bites into the metal and a square top section for applying a spanner to.b+q etc should provide them.
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Depending on much post you have to play with, you could turn it upside down and put the post in a vice, then twist the frame, using it for leverage to break the corrosion.
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try crush the seatpost in a vice & break out of the frame
just do this
dont bother pissing around drilling holes and soaking it in diesel
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try crush the seatpost in a vice & break out of the frame
just do this
dont bother pissing around drilling holes and soaking it in diesel
If it's alloy and it's in there solid, it'll proberbly snap before it lets go.
You know what it's like with steel BMX frames....they tend to bend before they snap. Where as alloy BMX frames just plain snap!
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The Sheldon Brown website has some good sound advice with regards to this problem.
He advises using ammonia rather than WD40 when dealing with alloy posts.
http://www.sheldonbrown.com/stuck-seatposts.html (http://www.sheldonbrown.com/stuck-seatposts.html)
I think his site is down at the moment. But I have found the page using the Way Back Machine.
http://web.archive.org/web/20050303172233/http://www.sheldonbrown.com/stuck-seatposts.html (http://web.archive.org/web/20050303172233/http://www.sheldonbrown.com/stuck-seatposts.html)
If that link fails, use the Way Back Machine yourself - www.archive.org (http://www.archive.org)
"use one of the yellow BMX saddles you have in the cellar that will never sell anyway" :LolLolLolLol:
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Arghhh, school chemistry. Acid for the steel and a base for the alloy. Makes sense hence the previous post re the caustic soda. I have some sodium hydroxide crystals around so I should be able to give it a go.
Many thanks
cd
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if all else fails drill the fooker out, takes forever if its a steel one but worth the effort to save a frame :daumenhoch:
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I used costic on my firebird did not touch the chrome on the frame and got the seat post out.
hope yours is not as far down as mine was cos it took ages but nothing else worked