# Super Stuck Seatpost



## RSW42 (Aug 22, 2006)

I've worked on countless bikes over the years, and have taken on a stuck seat-post here and there, and always prevailed.

I'm refurbishing (more like resurecting) an old Raleigh MTB for a team-mate @ work, and this sucker's seat post isn't stuck, it's STUCK...like Michael Moore to a KFC Family Chicken Bucket

Just wanted to see what other folks' ideas are that I may not have thought of.


Thanks,


S


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## selin (Nov 20, 2009)

Find a sturdy vice, turn the frame upside down, clamp the seatpost very tight, and try to turn the frame. Good luck!
ooh... and post some photos when you finish resurection.


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## lew s lugnut (Oct 26, 2005)

Get some PB blaster or other penetrating lube. Heat the frame and post with a heat gun or hair dryer on high if that's all you got. It will take longer to get some good heat with the hair dryer but if you use a heat gun be careful not to strip the paint. Once heated, spray penetrating lube on the post and let drip into frame. If you have the BB removed, try to squirt some lube into the seat tube of the frame through the bb. Let it sit, spray again, let it sit, spray again. (several days of this wouldn't hurt if you have time/patience).

Heat again, spray again, THEN put it in a vice or other method of removal.


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## logbiter (Dec 30, 2003)

galvanic corrosion? tried ammonia?
http://www.sheldonbrown.com/stuck-seatposts.html


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## wuzilla (Sep 9, 2008)

What materials are we working with? Steel to steel? Alloy to Alloy? 

You could do what Control Tech told me to do years ago - attach the seatpost to one car, and the frame to another, and drive in opposite directions. (Yes, I pretty much just hung up on them right there).


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## RSW42 (Aug 22, 2006)

Steel/steel


I've tried Sheldon's stuff, and per that, I can get the post to turn slightly...I did not have a lot of time to work on it last night, but will work on it more when i get home.


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## OldMTBfreak (Apr 8, 2006)

Soak the seat tube and seat post with diet coke. This is the best pentetrate i've found. The corrosion is not usually affected by various oils ( I like PB blaster thou). Use lots of heat, if the paint is not important, use a propane torch. No, it won't hurt the frame.


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## RSW42 (Aug 22, 2006)

OldMTBfreak said:


> Soak the seat tube and seat post with diet coke. This is the best pentetrate i've found. The corrosion is not usually affected by various oils ( I like PB blaster thou). Use lots of heat, if the paint is not important, use a propane torch. *No, it won't hurt the frame*.


Interesting...and we drink the stuff 

Yeah, I have mucho experience with heat application.

thanks for the input! :thumbsup:

.


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## wuzilla (Sep 9, 2008)

Steel/steel is actually pretty easy - double-so since you're working with pretty durable materials (ie, don't need to worry about thin wall aluminum, plastic-shards, etc.). You're basically just dealing with a bunch of rust - once you break that free, you're golden.

My example that had me calling Control Tech was alum/alum - now that was hard. Ended up cutting down the length of the post at a machine shop - wish I knew all the chemical tricks back then!

If you're willing to sacrifice the seatpost, the vice trick above is the easiest. Nothing get's better leverage then the frame itself.


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## mack_turtle (Jan 6, 2009)

sometimes they just don't come out. I had an old steel Fuji frame with an alu post stuck several inches in there. I tried twisting it in a vice and the aluminum just shredded in the vice now matter how hard I tightened the vice. then I tried soaking it in ammonia. then WD-40. then P B Blaster. then I poured Drano in the seattube and chased it with water til the frame was smoking. maybe that made it worse. then I drilled a hole through the post and inserted a bar through it sideways for some leverage in the vice. the bar snapped in half. so i put a stronger bar through the hole and the seatpost sheared in half. I started cutting long segments out of the seatpost with a hacksaw. after wrestling with this for months, I found someone who wanted to cut and weld some frames together to make a "tall bike" and I gladly gave it to him.


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## RSW42 (Aug 22, 2006)

Success...

A combantion of heat (torch), penetrating oil, and knocking frame near seatpost with a mallet and piece of wood won the day...it was a hard fight, but I prevailed...


Thanks for the ideas!



S


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## Bataivah (Feb 19, 2011)

I would machine it out before I used heat on a frame. If you ruin the temper of it you will soften it or make it brittle.


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## lew s lugnut (Oct 26, 2005)

Their are no worries about affecting the heat treating. If you don't bubble the paint (and even if you do) you aren't going to get it hot enough with a heat gun or hair dryer to affect the heat treating. Heat treating brings the temp up close to the melting point.


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## Bataivah (Feb 19, 2011)

Heat treat is around 900-1000 degrees. The melting point is around 2500 degrees.
I'm just set in my ways and won't heat a bike frame. I know the the bike mechanics
that I've talked to say the same thing but I'm sure there are some that will do it. Any Metalurgists out there?


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## mitzikatzi (Sep 9, 2008)

Try Sheldon Brown



> If nothing else works, the final resort is the old hacksaw blade trick. Cut the seatpost off so that about 1/2" is left sticking out, then insert a hacksaw blade into the seatpost and carefully cut a slit in the post. This is very laborious, and you run the risk of damaging the frame if you cut too far, but this approach cannot fail. Once you have cut the slit, grab one edge of the cut with a locking plier and roll the seatpost up inside itself and pull it out.


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## RSW42 (Aug 22, 2006)

Bataivah said:


> I would machine it out before I used heat on a frame. If you ruin the temper of it you will soften it or make it brittle.


It's an old, lower-end bike that he just wants to be able to run errnads around campus on.

I didn't feel the need to go that deep.


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## RSW42 (Aug 22, 2006)

The paint did not bubble

I used heat sparingly (I know how to use it...used to be a car mechanic way back when)

Again, old, low-end bike just for running errands on campus. 


JM (owner) is not going to go out and enter a world cup race on this bike.  



.


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## bad mechanic (Jun 21, 2006)

Bataivah said:


> Heat treat is around 900-1000 degrees.


1600 degrees for 4130, which the vast majority of quality steel bike frames are made from. In additional, virtually no one in the industry heat treats a cromoly bike frame after welding. No heat gun will ever get a frame as hot as a welding torch.

Reference:
http://forums.mtbr.com/showthread.php?t=352508


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## customfab (Jun 8, 2008)

logbiter said:


> galvanic corrosion? tried ammonia?
> http://www.sheldonbrown.com/stuck-seatposts.html


That works almost every time, but you need pure ammonia. Not the heavily diluted stuff you find at the local piggily wiggily.


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## Ecogeek (Aug 30, 2009)

lew s lugnut said:


> Get some PB blaster or other penetrating lube. Heat the frame and post with a heat gun or hair dryer on high if that's all you got. It will take longer to get some good heat with the hair dryer but if you use a heat gun be careful not to strip the paint. Once heated, spray penetrating lube on the post and let drip into frame. If you have the BB removed, try to squirt some lube into the seat tube of the frame through the bb. Let it sit, spray again, let it sit, spray again. (several days of this wouldn't hurt if you have time/patience).
> 
> Heat again, spray again, THEN put it in a vice or other method of removal.


If the frame is steel, this advice is fine. If it's 6061 and you use too much heat, you'll change its temper, annealing it and making it soft as shite. Most other alloys would be ok w a heat gun. But 6061 changes fast at pretty low temps.
Minor warming will be ok, but not v effective as high contact area and high heat conductivity of alu will warm post just as fast.

Oh. Take bb out first, and spray liquid wrench up seat-tube (frame inverted obviously) first. Let it sit.
One thing heating does really well is it gets any air to bubble out from between tube and frame, then, as it cools, it'll suck the juice back into the spaces. Do this a few times. Low temps if it's 6061. I would bash the top of it with the 1lb rubber mallet. Maybe put a junk saddle on it first. Drive it into the frame a fraction of an inch to break the lock. Then twist it out. Have done this before on a mega-STUCK post that was not only wrong size but had been left in for 10yrs on heavily corroded frame with bolt-up clamp.


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