"Frozen" Seatpost

marple_dave
marple_dave Posts: 23
edited February 2012 in Workshop
I have an alloy seatpost "frozen" into a steel frame which I would like to remove. I am not too fussed about the seatpost (thinking about replacing it with a carbon version) but would like the frame to come through the operation undamaged. Any suggestions on how to remove the seatpost from the frame would be gratefully received?

Here's hoping.

Dave

Comments

  • Monty Dog
    Monty Dog Posts: 20,614
    Sheldon Brown has all the answers:
    http://sheldonbrown.com/stuck-seatposts.html
    Make mine an Italian, with Campagnolo on the side..
  • kentphil
    kentphil Posts: 479
    Try lots of WD40 sprayed where the post goes into the frame. Leave to soak overnight. Then attached the top of the seat post to a vice and twist the frame.

    That's what I did anyway.
    1998 Kona Cindercone in singlespeed commute spec
    2013 Cannondale Caadx 1x10
    2004 Giant TCR
  • Yossie
    Yossie Posts: 2,600
    No to WD40, yes to penetrating spray over a period of hours and left overnight, yes to seat post in a vice and using the frame as a lever.
  • marple_dave
    marple_dave Posts: 23
    Thanks all.
  • Monty Dog
    Monty Dog Posts: 20,614
    Use a penetrating fluid like Plus Gas or ACF30 if the stuck post is aluminium. You could just use huge amounts of force - I saw someone 'unwrap' a seat-tube from a lovely Pinarello by doing this.
    Make mine an Italian, with Campagnolo on the side..
  • baznav73
    baznav73 Posts: 111
    As a last resort i have heard of people useing caustic soda on steel frames, disolves the alloy but not the steel.
  • on-yer-bike
    on-yer-bike Posts: 2,974
    Coca Cola poured in form the bottom bracket with frame upside down i've heard works.
    Pegoretti
    Colnago
    Cervelo
    Campagnolo
  • Eyorerox
    Eyorerox Posts: 43
    After the WD 40 treatment try some boiling water.
  • nickellis
    nickellis Posts: 239
    on-yer-bike wrote:
    Coca Cola poured in form the bottom bracket with frame upside down i've heard works.

    Just read this post as i was tipping a can down my gullet. Now worried that my throat looks like the inside of a rusty steel frame....
    Trek 1.1c (2012) - For commuting
    Trek Madone 5.5c (2010) - For pleasure http://i1151.photobucket.com/albums/o62 ... G_0413.jpg
  • keef66
    keef66 Posts: 13,123
    Stick to drinking the coke. All it will do to a bicycle frame is make it all sticky.

    Gallons of Plus Gas over a 24-48 hour period, if possible, half of it applied via the BB into the seat tube.

    Seat post clamped in a bench vice, twist the frame.
  • eccles
    eccles Posts: 96
    Brute force, ignorance and a 3 foot Stilsons pipe wrench worked for me when my seatpost stuck. Once I'd got it moving I clamped the seatpost in a vice and kept twisting the frame around for about 20 minutes. It gave up eventually but then, so did I :)
    I've had a quill stem stuck in a steerer tube before as well and I got that out by cutting the top off and then cutting slots into the side of the stem and finally knocking the pieces out.
    Low tech solutions but with enough determination they will always work. As a side note, the seatpost and the stem were both written off afterwards but I didn't care about that as I had replacements for both.
  • marple_dave
    marple_dave Posts: 23
    Monty Dog wrote:
    Use a penetrating fluid like Plus Gas or ACF30 if the stuck post is aluminium. You could just use huge amounts of force - I saw someone 'unwrap' a seat-tube from a lovely Pinarello by doing this.
    Cheers mate. Just sorted some of this stuff following earlier advice.
  • mikenetic
    mikenetic Posts: 486
    It's quite possible to bend your frame if you're not careful with the clamp & twist approach.

    If it's not budging at all then you could get the seatpost reamed out.

    Also, a very strong caustic soda solution will dissolve the Alu post without harming the steel. Protect the paintwork if you do this. And your eyes and lungs. That stuff is evil. Check the picture in this thread for the remains of a seatpost removed chemically. http://www.lfgss.com/thread3816.html

    You may want the seat tube very lightly reamed after removal to make sure it's fully cleaned up and ready to take a new post. And obviously you'll need to make sure there's no trace of the caustic soda left in there at all.
  • delstron
    delstron Posts: 74
    No one has mentioned Ammonia. This worked for me on a similar problem. Frame in vice held by seatpost, upside down. Ammonia in at the bottom bracket, leave overnight. Start twisting the frame whilst pulling up.

    Ammonia from Wilko's, it's not full strength stuff but good enough.

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