stuck seatpost

andy610 Posts: 602
edited May 2008 in Road beginners
i cant get my carbon seatpost to move, im trying to get my seatpost higher but its stuck and you cant use oil etc due to weakening of the carbon, ive tried using a wooden mallet on the side of the seat it only moved it sideways one inch and now i cant get it back, any ideas


  • Slow Downcp
    Slow Downcp Posts: 3,041
    I'd have thought plusgas or WD40 would be safer than tapping the saddle sideways which will put stresses on the seatpin.
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  • feel
    feel Posts: 800
    What is the frame tube made of?
    We are born with the dead:
    See, they return, and bring us with them.
  • andy610
    andy610 Posts: 602
    the frame is made of aluminium
  • feel
    feel Posts: 800
    Use a hair dryer or hot air gun on it to expand the frame tube. As soon as you've heated it, very quickly twist the seat post using the seat. Good luck

    (be careful if you use a hot air gun as it it could bubble the paint)
    We are born with the dead:
    See, they return, and bring us with them.
  • mathi
    mathi Posts: 110
    Last year i had a carbon post stuck in my Lemond carbon frame , Trek suggested using coca cola :? they say the acids in it break down any residues built up between the frame and post :? no i never got it out intact :roll:
  • andy610
    andy610 Posts: 602
    no nothings worked for mine im having to cut it in half then use a hacksaw blade down the tube and cut through it im never going to get a carbon seatpost again just alloy
  • Cheshley
    Cheshley Posts: 1,448
    I got the post out of my old MTB by turning the bike upside down, clamping the post in a vice and turning the bike. You get much more leverage this way than just trying to twist the post.
    1998 Marin Hawk Hill
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  • McBain_v1
    McBain_v1 Posts: 5,237
    Agree with the alloy seat post remark, carbon seat posts seem particularly vulnerable to both slipping and then locking up.

    I'd be really hesitant about putting my entire bike upside down in a vice :shock:

    What do I ride? Now that's an Enigma!
  • natrix
    natrix Posts: 1,111
    I picked up this tip from a team mechanic. To free a carbon seat post (it doesn't work on alloy or titatnium ones) make up a solution of 1 part coke, 2 part urine and 1 part vingar. Soak rags in this and wrap around the seat post. Don't store the solution, make up a fresh batch each time!
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  • robmanic1
    robmanic1 Posts: 2,150
    Barnesr - you're taking the p*ss :wink:
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  • ricadus
    ricadus Posts: 2,379
    Sheldon Brown's advice about seatposts is more relevant to alloy ones than carbon (i.e. where he refers to use of grease to avoid a stuck post).

    Great choice of quote at the end of his article though (Martin Luther King's "Free at last! Thank God almighty, we are free at last!")

    Avoiding a stuck carbon post can be as simple as periodically loosening it or even removing it, perhaps whenever you clean the bike. Don't use oils or grease as they may cause the surface post material to fractionally expand, jamming it, or dry out and act like a shim on the the inside surface of the frame.

    I have this theory – ricadus's law – that a carbon seatpost is more likely to be found stuck in the frame the later you put off packing up the bike before the early morning holiday departure.
  • nmarchini
    nmarchini Posts: 109
    best way to avoid this problem with carbon posts is to get a shim and a slightly slimmer post.
    Bikes - '97 GT Psyclone, '94 Kona Condercone, '05 Rock Lobster Team TIG SL.