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Thread: stuck seat post

  1. #1
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    stuck seat post

    Hi I have a seat post stuck in a frame that was donated to our co-op.
    the seat post is over 1ft into the frame and I have used penetrating oil both from the bottom (through a frame hole) and from the top
    We cant attach a seat for working the post out, but thats not too much of an issue. (broken seat post).
    We tried hacksawing the post and rolling the post inwards but since its so long the bottom 1/2 of the post still seems fuzed to the frame.
    We have also tried more penetrating oil after rolling much of the seat tube in but it still wont budge.

    I havent seen any posts which had any other ideas... anyone... what next?

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    do you have any post sticking out still?

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    Real Men Ride Ordinaries fuzz2050's Avatar
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    with that much of the post in the frame, it's going to be tough no matter what. It's times like this you have to ask,' is the frame realyl worth it?'

  4. #4
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    Quote Originally Posted by chico1st View Post
    Hi I have a seat post stuck in a frame that was donated to our co-op.
    the seat post is over 1ft into the frame and I have used penetrating oil both from the bottom (through a frame hole) and from the top
    We cant attach a seat for working the post out, but thats not too much of an issue. (broken seat post).
    We tried hacksawing the post and rolling the post inwards but since its so long the bottom 1/2 of the post still seems fuzed to the frame.
    We have also tried more penetrating oil after rolling much of the seat tube in but it still wont budge.

    I havent seen any posts which had any other ideas... anyone... what next?
    You need to work harder with the hacksaw.

    +1 Post #3's concern about frame worth
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

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    Bicycle Repair Man !!! Sixty Fiver's Avatar
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    It can be an arduous task to cut out the seatpost especially when there is a lot of it there but if everything else fails this is the best and least destructive option.

    If one penetrant does not work another might... PB Blaster gets rave reviews but ammonia and WD40 also work.

    I don't use saddles to provide leverage as the rails often can't take the stress... a bar end can usually be clamped down to to a seatpost to provide leverage and you can also drill straight across the seat tube so that you can insert a small but stiff bar.

    With this you can try and remove it while the bike is in he stand or on the floor or can provided a stop for when you put it in the vise and turn the frame.

    The last post I had to remove was on my Ron Cooper and if there was a bike that one wanted to save, this would have been it.

    Soaking it yielding no good results and when out into the vice the seat post pretty much crumbled so it was 3 hours of using the saw to cut it out...

    Gave it a few little taps from above with the hammer and had it drop right into the frame but was okay with this as the club shaped cutout in the bb provided a spot for me to tap it out from the bottom.

    And then there was much cheering and dancing in the shop.

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    Quote Originally Posted by chico1st View Post
    Hi I have a seat post stuck in a frame ...
    1) what is the frame material?
    2) what is the post material?

    I had a really stubborn aluminium post stuck in a steel frame once. After considerable amounts of fruitless fiddling I took a length of broom handle, split it down the middle and glued in a hacksaw blade between the halves. With this extra leverage it didn't take too long to cut a slit all the way down the post from the inside, after which the post could be collapsed inwards and pulled out.

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    steel frame with aluminum post I like that broom handle idea
    I was considering taking a reamer to it... but really didnt want to.
    Last edited by chico1st; 02-25-10 at 10:17 AM.

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    50/50 Road/eBike Commuter kmcrawford111's Avatar
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    This is just an idea - what about applying heat? I've seen others do this to free stuck parts, and I just did it myself to get out one of my BBs. I tried everything underneath the sun before it, and it was still dfficult to muscle it out, but the heat got the job done. Is there some reason not to do this in this situation?

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    Senior Member jack002's Avatar
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    I'd heard of people putting the seat post in a bench vice with lots of penetrating lube using the whole frame for leverage.
    Biking isn't a sport because anybody can do it. I can bike, you can bike. For goodness sakes, my mother can bike! You don't see her on the cover of Sports Illustrated, do you?

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    Ammonia is often very effective, but only if used before penetrating oil is used. Once you've soaked it all in penetrating oil, the ammonia will no wick between the post and frame.

    At some point you have to do an assessment and decide whether you're ready for desperate measures to save a frame that otherwise you'd trash. Once you've determined that you've reached that point, try the following with the understanding that it'll either free the post or finish off the frame.

    Mark the post about 1/8" above the seat lug for reference. Wear face or at least eye protection. Support the BB shell (preferably with cups still installed) directly on an anvil or anvil substitute. I use an old 100# tree stump. Have someone hold the frame with the seat tube vertical and use the largest hammer you have, such as a 4# stone cutters mallet, and try to drive the post in using a single heavy blow. For this to work, the frame must be properly dollied and you have to use powerful blows, because repeated lighter blows will only mushroom the top of the post. You can deliver far more concentrated energy this way than would ever be possible trying to pull or twist the post. and one of three things will happen.

    Either the post will budge, meaning it's now broken free & you can begin carefully and slowly twisting it out. (Be careful about heat as you twist or it could re-bind) If it doesn't break free there's a good chance that you'll upset (cause a small buckle) the seat at the inner end of the post, or ovalize the BB shell.

    As I said, this is a method of last resort, because it either works, or finishes off the frame.
    Last edited by FBinNY; 02-26-10 at 11:03 AM.
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    I've used a large pipe wrench to turn a seat post as I pull it out before. I like the idea of putting the seatpost in a bench vice.
    I'm just a kid who gets in trouble sometimes

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    It seems that for soaking some ammonia mixed with a detergent would be enough to eventually get the penetrating oil out. The broom/hacksaw is clever. I would have suggested a reamer, but as you've already thought of that I imagine you're having a hard time getting past the wear on the reamer vs. the value of the frame. A really big drill bit on a stalk might bore out enough that you could twist out the rest, but you're likely to destroy the frame in the process. If it's a steel frame I recommend Liquid Wrench over PB Blaster, which I recommend over WD40.

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    i just helped a friend get an extremely stuck seatpost out of a nice bob jackson frame. no access to a bench vise so we used two cement blocks at the park that had just enough space to wedge a beater saddle attached to the stuck seatpost. we turned it upside down and started rotating the frame and nothing moved. we really muscled it but stopped short since he was worried about warping his frame.

    so then he used PB Blaster and vibrated the seatpost for a couple weeks to get good penetration. we collected another old disposable saddle, a thermos of boiling hot water and a can of "Dust Off" compressed air from the office supply store. we again wedged the saddle, poured very hot water on his seattube and blasted the seatpost with the "Dust Off" can turned upside down which makes it spew super cold liquid. we were hoping the hot water would expand the steel seattube and the super cold would contract the aluminum seatpost. we did this a coupe times alternating torquing on his frame and success! the saddle totally disintegrated from the effort and the last couple inches took us both standing on the saddle rails and pulling up with our collective effort but happy to report it as a successful technique.

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    I'd heard of people putting the seat post in a bench vice with lots of penetrating lube using the whole frame for leverage.
    I already tried that... i broke my vice

    and i blow torched it... which i regret now becuase the paint is all screwy. The issue there was that there was so much post to heat up.. i think thats why it didnt work

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    boiling hot water and a can of "Dust Off"
    Thats crazy but I like it

    So its a steel frame with an aluminum post ive heard different things (even within this thread) do i want ammonia or something like PB Blaster?

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    Senior Member FR4NCH1SE's Avatar
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    God I love grease, puts some grease on that post and this problem doesn't happen. GL thou.
    "Every Man Dies, Not Every Man Really Lives".

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    To chico1st: You should do a thorough search of these forums and the Internet with the keywords 'stuck seat post' or 'aluminum seat post steel frame'. You will find a wealth of information.

    My story: I had about nine inches of aluminum seatpost stuck in a steal seat tube, with only about a 1/4 to 1/8 of an inch above the clamp. The seatpost had been in there for 23 years or longer. It was "welded" to the inside of the seat tube. I think it's called a galvanic or anodic weld, for which, according to what I have read, penetrating oils, heat/cold treatments, and even a concentrated ammonia solution will generally not work. I tried the hacksaw technique, but there was just too much post in there; I got about four inches peeled away, but that was it.That left reaming, which of course requires a reamer and several different sized cutters (maybe the wrong word) and a very steady hand, or melting the post chemically with lye. I did the latter, which I cannot recommend unless you truly have to have that frame for some reason, because lye is EXTREMELY DANGEROUS in the concentrations needed to dissolve aluminum (or in any concentration for that matter). You MUST do ample research before attempting the lye treatment or else you might suffer SEVERE burns to skin and eyes with PERMANENT damage.

    You all: I know, I know, perhaps I shouldn't have mentioned the lye approach because of the hazards involved, but the OP asked for other ideas so I gave him one.
    Last edited by caintuck; 02-27-10 at 05:38 AM.

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    First rule for handling Sodium Hydroxide - Lye - is to wear full protective covering to your face and eyes and hands. And be prepared to jump in a shower in a big hurry if any spills on your clothes.

    Rule 2: Never add water to lye. Always add the lye to water - slowly! - while stirring to dissolve. If you add water to the lye, the water will boil and spatter hot lye all over the place.

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    In case this hasn't been mentioned... when you start putting your frame in a vice or start using snipes you can really f up a frame.

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    Senior Member jack002's Avatar
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    Oh, I like the whole lye thing. Adding risk to life and limb for a frame, I just hope its worth it all. The drama added to the thread makes it worth the read.
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    Does caustic soda eat steel? It eats aluminium.

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