Advertise on Bikeforums.net



User Tag List

Page 1 of 2 12 LastLast
Results 1 to 25 of 26
  1. #1
    Senior Member
    Join Date
    Feb 2013
    Location
    North Queensland, Australia
    My Bikes
    '84 Repco Nishiki Olympic 12,'87 Peugeot Montblanc,'04 Fuji Hardtail Outland Comp, '74 Raleigh Sports
    Posts
    139
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Stuck seatpost cost-benefit analysis

    Hi al,
    Picked up a Kona Stuff for $50 that looks to be from about 2003, with the intentions of flipping it.
    The bike is in pretty good condition, except the seatpost is stuck. With some effort, the post rotates in the frame, but will not go higher or lower (something I have never experienced before).
    I have never gotten to the point that i need to consider using the hacksaw trick, but this seatpost really doesn't want to come out of the frame.
    My question: how much time and energy goes into extracting the post with a hacksaw blade. It sounds... awful. I am tossing up between stripping the parts (alivio group, 1 deore hydraulic disc brake, Zokes (?) triple clamps) and ditching the frame, or putting the effort in to get the bastard out and sell the compete bike (probably for $300 +/- 20% in my market, with a further 50-100 to spend).
    Cheers.

  2. #2
    Senior Member Kopsis's Avatar
    Join Date
    Apr 2008
    Posts
    487
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    If the seatpost rotates at all, then you are nowhere near needing a hacksaw. Apply a liberal dose of penetrating oil (PB Blaster, CRC Freeze Off, etc.) daily and keep working to loosen it up. Apply the penetrating oil from both ends of the seat tube (pull the BB, if you haven't already, to get access and keep it from getting soaked in penetrating oil). Ideally, clamp the post in a vise and twist the frame back and forth while pulling up with as much force as you can muster. A large pipe wrench (36" or more) can be an effective alternative if you don't have a vice (and don't plan to re-use the seatpost). Don't be afraid to put some force into it -- it's pretty amazing how much torque/tension a seat tube can handle.

  3. #3
    Senior Member
    Join Date
    Feb 2013
    Location
    North Queensland, Australia
    My Bikes
    '84 Repco Nishiki Olympic 12,'87 Peugeot Montblanc,'04 Fuji Hardtail Outland Comp, '74 Raleigh Sports
    Posts
    139
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yeah that was my thinking initially. On closer inspection I can see that the old owner has tried the vise trick, there are marks on the top of the seatpost.
    Is there some likely cause of the problem that lets the seatpost rotate but not go up or down? I thought that was strange.

  4. #4
    Senior Member Wilfred Laurier's Avatar
    Join Date
    Feb 2013
    Posts
    1,572
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    if the seatpost is stuck
    the bike is worthless to anyone except the 0.5% of the population who have exactly the right leg length

    so i dont know how much it would be worth before or after
    just that with the seatpost stuck it is worth much much less
    the fifty dollars you paid is probably about right
    regardless of what other work has been done to the bike

  5. #5
    Senior Member
    Join Date
    Aug 2005
    Location
    Pittsburgh, PA
    My Bikes
    '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
    Posts
    25,574
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    A remote possibility but is the seatpost the type that uses an expander wedge (like a quill stem) to tighten in place? If so the wedge may be stuck and could be knocked loose by backing out the bolt and hitting it on the head with a hammer like you do to loosen a quill stem.

  6. #6
    pan y agua merlinextraligh's Avatar
    Join Date
    Aug 2005
    Location
    Jacksonville
    My Bikes
    Wilier Zero 7; Merlin Extralight; Co-Motion Robusta; Schwinn Paramount; Motobecane Phantom Cross; Cervelo P2; Motebecane Ti Fly 29er
    Posts
    27,292
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)
    Given that the seatpost is already marked up, I'd be inclined to just cut it. It's going to be quicker to hacksaw it, than it is to keep putting penetrating oil on it and waiting.

    Hacksawing it out might take 15 minutes.

    If you can save the seatpost, it would obviously be cheaper, so it's a question of time versus money.
    You could fall off a cliff and die.
    You could get lost and die.
    You could hit a tree and die.
    OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.

  7. #7
    Senior Member
    Join Date
    Feb 2014
    Location
    Southern Ontario
    Posts
    82
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Any chance that a water bottle cage bolt is pushing into the seat post? Only thing that I could think of that might let a post rotate but not move vertically.
    If there is room to get on it, an air impact chisel (zip ***) underneath the top of the post is supposed to work well. You can even drill a hole crosswise through the seat post, put a bar in the hole and then use the airgun against the bar.

  8. #8
    Senior Member Kopsis's Avatar
    Join Date
    Apr 2008
    Posts
    487
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by merlinextraligh View Post
    Given that the seatpost is already marked up, I'd be inclined to just cut it. It's going to be quicker to hacksaw it, than it is to keep putting penetrating oil on it and waiting.

    Hacksawing it out might take 15 minutes.

    If you can save the seatpost, it would obviously be cheaper, so it's a question of time versus money.
    15 minutes?! Not doubting you, but I'd sure like to know your trick. Last time I went down that road it took me the better part of four hours (and that was after dissolving a good portion of the post in sodium hydroxide).

  9. #9
    Senior Member
    Join Date
    Jan 2012
    Location
    Spokane, WA
    My Bikes
    Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520
    Posts
    2,227
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    If it rotates, it will come out provided there isn't any oddness like a water bottle bolt sticking into it. You just need more strength. Strip the frame so there is no fork, no rear wheel and maybe remove cranks if they become an annoyance. Then have 2 big strong people pulling and twisting against the frame and seat.

    I strip the frame just to make it easier to grab and move around.
    "When dealing with stuff like this consider that this is a bicycle, not a spaceship." -- FBinNY

  10. #10
    Senior Member Kopsis's Avatar
    Join Date
    Apr 2008
    Posts
    487
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Rest_assured View Post
    Yeah that was my thinking initially. On closer inspection I can see that the old owner has tried the vise trick, there are marks on the top of the seatpost.
    Is there some likely cause of the problem that lets the seatpost rotate but not go up or down? I thought that was strange.
    Corrosion burrs in the seat tube could have actually cut grooves in the seatpost during previous removal efforts. Moving within the established grooves would offer less resistance than trying to "cut" new ones. Even a small burr can really hang things up. I like the air hammer suggestion as the shock can be really effective for shattering the oxide residues.

  11. #11
    Senior Member
    Join Date
    Jul 2008
    Location
    Seattle
    My Bikes
    91 Trek franken '81 Schwinn Voyager
    Posts
    133
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    15 minutes doesn't seem out of line with the right tools. There are several "hand grips" made that will hold a blade and allow long, accurate strokes. I've used a reciprocating saw, carefully, slowly, in situations like this to do the majority of work-I then finish with a hand held blade. There are also hand "vises" that will hold the long, tough, blades designed for reciprocating saws rather than the usual hand saw blades. Good luck.
    Nobody slower, and nobody lovin' it more...

  12. #12
    pan y agua merlinextraligh's Avatar
    Join Date
    Aug 2005
    Location
    Jacksonville
    My Bikes
    Wilier Zero 7; Merlin Extralight; Co-Motion Robusta; Schwinn Paramount; Motobecane Phantom Cross; Cervelo P2; Motebecane Ti Fly 29er
    Posts
    27,292
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Kopsis View Post
    15 minutes?! Not doubting you, but I'd sure like to know your trick. Last time I went down that road it took me the better part of four hours (and that was after dissolving a good portion of the post in sodium hydroxide).
    cut the top off close to the frame, that should take less than a minute.

    Cut slot in the seatpost with a keyhole saw, maybe another couple minutes. Cut another slot, and remove piece. If it doesn't come out then, cut another slot or two until it does.
    You could fall off a cliff and die.
    You could get lost and die.
    You could hit a tree and die.
    OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.

  13. #13
    Senior Member
    Join Date
    Feb 2013
    Location
    North Queensland, Australia
    My Bikes
    '84 Repco Nishiki Olympic 12,'87 Peugeot Montblanc,'04 Fuji Hardtail Outland Comp, '74 Raleigh Sports
    Posts
    139
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by merlinextraligh View Post
    cut the top off close to the frame, that should take less than a minute.

    Cut slot in the seatpost with a keyhole saw, maybe another couple minutes. Cut another slot, and remove piece. If it doesn't come out then, cut another slot or two until it does.
    The 'hacksaw trick' as I interpreted it is to cut the post at about 2cm above the seat tube, and use a blade down into the post to cut through the post lengthways. The post can then be kind of bent and spiralled into itself and pulled out. If we are talking about the same thing, 15 minutes sounds like a no-brainer, but I was thinking it would be more like Kopsis' suggestion (4hrs+).

  14. #14
    Senior Member
    Join Date
    Feb 2013
    Location
    North Queensland, Australia
    My Bikes
    '84 Repco Nishiki Olympic 12,'87 Peugeot Montblanc,'04 Fuji Hardtail Outland Comp, '74 Raleigh Sports
    Posts
    139
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    No mount for drink bottle on the seat tube, and it's not a quill seat post btw.
    Thanks for the help, everyone. I'll report back when I have reached a solution.

  15. #15
    Senior Member CroMo Mike's Avatar
    Join Date
    Nov 2013
    Location
    Short Pump, Virginia
    My Bikes
    1972 Bottecchia Pro, 1982 Colnago Super, 1987 Bottecchia Team, 1995 Bianchi Campione d'Italia
    Posts
    404
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Bench vise. Slide hammer. Air chisel. Recip saw (sawzall). It doesn't stand a chance. But how do all these posts and stems get stuck in the first place?

  16. #16
    Senior Member bikemig's Avatar
    Join Date
    Apr 2012
    Location
    Middle Earth
    My Bikes
    A lot of old bikes and a few new ones
    Posts
    3,894
    Mentioned
    14 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by CroMo Mike View Post
    Bench vise. Slide hammer. Air chisel. Recip saw (sawzall). It doesn't stand a chance. But how do all these posts and stems get stuck in the first place?
    Neglect and time.

  17. #17
    Senior Member
    Join Date
    Feb 2013
    Location
    North Queensland, Australia
    My Bikes
    '84 Repco Nishiki Olympic 12,'87 Peugeot Montblanc,'04 Fuji Hardtail Outland Comp, '74 Raleigh Sports
    Posts
    139
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by bikemig View Post
    Neglect and time.
    True, or somebody using the wrong size.
    But neither of those causes seem to apply here, the bike seems to be relatively well cared for, and from what i can tell the post is the right size.

  18. #18
    Senior Member
    Join Date
    Dec 2011
    Posts
    138
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by merlinextraligh View Post
    Given that the seatpost is already marked up, I'd be inclined to just cut it. It's going to be quicker to hacksaw it, than it is to keep putting penetrating oil on it and waiting.

    Hacksawing it out might take 15 minutes.

    If you can save the seatpost, it would obviously be cheaper, so it's a question of time versus money.
    15 mins if there is only two inches of post
    in the tube.
    In my experince ya gotta cut two slots to get
    it out. It is a thick strong tube and the curling it around
    idea doesn't work.

  19. #19
    Senior Member
    Join Date
    Sep 2004
    Location
    boston, ma
    Posts
    2,815
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    spin the post 90 degrees then take a hammer and knock it out.

  20. #20
    Senior Member
    Join Date
    Feb 2013
    Location
    North Queensland, Australia
    My Bikes
    '84 Repco Nishiki Olympic 12,'87 Peugeot Montblanc,'04 Fuji Hardtail Outland Comp, '74 Raleigh Sports
    Posts
    139
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by reptilezs View Post
    spin the post 90 degrees then take a hammer and knock it out.
    Can you expand on that a little bit please?

  21. #21
    Senior Member
    Join Date
    Nov 2003
    Location
    Minneapolis, MN
    My Bikes
    2x Bianchi, 2x Specialized, 3x Schwinns
    Posts
    309
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Kopsis View Post
    15 minutes?! Not doubting you, but I'd sure like to know your trick. Last time I went down that road it took me the better part of four hours (and that was after dissolving a good portion of the post in sodium hydroxide).
    +1 on the 4 hours. That was my experience last summer. But I did get that sucker out.

  22. #22
    Senior Member
    Join Date
    Sep 2004
    Location
    boston, ma
    Posts
    2,815
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Rest_assured View Post
    Can you expand on that a little bit please?
    twist it so the nose is point 90 degress off of straight ahead, this brings the saddle clamp head out. now you have clearance to smash on it with a hammer

  23. #23
    Senior Member ClarkinHawaii's Avatar
    Join Date
    Jan 2010
    Location
    Wahiawa. Oahu
    Posts
    1,156
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    It seems like the method you should use would depend upon what material the seatpost is made of, and how much seatpost (how many inches) is stuck in the seat tube.

  24. #24
    Senior Member
    Join Date
    Mar 2008
    Posts
    4,214
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I've cut a piece of a broom handle in half lengthwise, glued in a hacksaw blade overhanging the edge about the thickness of the post. Worked like a charm compared with a handheld bare blade. Don't remember exact time, but closer to 15 minutes than 4 hours anyhow.

  25. #25
    Insane Bicycle Mechanic Jeff Wills's Avatar
    Join Date
    Mar 2008
    Location
    other Vancouver
    Posts
    6,772
    Mentioned
    16 Post(s)
    Tagged
    0 Thread(s)
    Strip the bike, including the cranks. Invert the frame and fill the seat tube with penetrating oil. Let it soak for a while, then grab the seatpost in a bench vice. Spin the frame around while pushing it upward- it should "unthread" itself from the seatpost.

    You'll want to clean up the inside of the seattube with a straight reamer before installing a new post.
    Jeff Wills

    All my bikes.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •