Advertise on Bikeforums.net



User Tag List

Results 1 to 8 of 8
  1. #1
    Junior Member
    Join Date
    Jul 2009
    Posts
    6
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    aluminum seat post stuck in steel frame removal (success) story

    I bought a vintage Trek frame a few weeks ago only to find the seatpost severely stuck in the frame. The guys at the LBS put it in the table vise but it wouldn't budge. I finally got it out by soaking it in ammonia and then using a pipe wrench. Here's what I learned here and elsewhere about stuck seat posts:

    * Pay attention to what metals you are working with. I figured my post was aluminum because a magnet did not stick (though apparently this is not a foolproof test). The LBS guys heated up my post which would actually cause it to expand (in a way this could still be good after the post cooled down, maybe?). Apparently with steel frame and aluminum post you want to cool everything and then heat the frame because the steel will expand faster than aluminum (saw that on a post here I believe). I eventually removed the seat post without using any heating or cooling.

    * Sheldon is right that ammonia eats at the corrosion that forms between steel and aluminum. I turned the bike over and poured the ammonia (bought it at Kroger grocery for $1.99) into the seat tube from the bottom bracket area. I was able to fill up the whole seat tube until I could see from the BB hole that it was full (it leaked out very slowly if at all -- luckily my seat post was impermeable and I did not have to use any tape). I let it sit for about 48 hours, occasionally banging a bit with wood on the seat post and seat tube hoping to move things around a bit.

    * Sheldon might be wrong when he says not to use a pipe wrench. A pipe wrench, I found out, is designed to tighten onto a round pipe as you pull. I was finally able to free my post by putting the pipe wrench on there, laying the bike over, and, using the ground as leverage against the end of the pipe wrench, standing on the whole thing so that the force of my weight downward turned the wrench.

    * There's this place called Harbor Freight that has ridiculously cheap tools and other hardware store items (thanks to the LBS for this tip!). If there is one near you I would definitely check it out: http://www.harborfreight.com/cpi/ctaf/retail_stores.taf

    * Word, thanks to everyone else who posted on stuck seat posts and helped me free mine!
    Last edited by kinokokun; 07-13-09 at 03:17 PM.

  2. #2
    Great State of Varmint Panthers007's Avatar
    Join Date
    Sep 2008
    Location
    Dante's Third Ring
    Posts
    7,481
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    The LBS might want you to shop at Harbor Fright (as I call it) as their tools are cheap and tend to break - or damage what you're working on. Then you'll need to take your bike back to the LBS for surgery.

    Perhaps this may be a cynical point-of-view, but Harbor Fright tools, by and large, are garbage. There are a few exceptions though. My advice is to save up your money to by the BEST tools made for bicycles. Unlike Harbor Freight's offerings, you won't end up buying top-quality tools twice.
    How do you keep an idiot in suspense?

  3. #3
    Junior Member
    Join Date
    Jul 2009
    Posts
    6
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Panthers007 View Post
    The LBS might want you to shop at Harbor Fright (as I call it) as their tools are cheap and tend to break - or damage what you're working on. Then you'll need to take your bike back to the LBS for surgery.

    Perhaps this may be a cynical point-of-view, but Harbor Fright tools, by and large, are garbage. There are a few exceptions though. My advice is to save up your money to by the BEST tools made for bicycles. Unlike Harbor Freight's offerings, you won't end up buying top-quality tools twice.
    Yeah I think it depends a lot on what you are getting. I got some compartmentalized plastic storage cases for a couple of bucks, locktite $1.99, a big steel pipe wrench $7.99, a nice hammer $2.99, orange hand cleaner $1.99. I probably wouldn't go for their $14.99 drill, though.

  4. #4
    use your best eye kenhill3's Avatar
    Join Date
    Mar 2006
    Location
    Olympia, Washington
    My Bikes
    '75 Bertin, '93 Parkpre Team 925, '04 Kona King Kikapu, '05 Bianchi Vigorelli
    Posts
    3,054
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Panthers007 View Post
    The LBS might want you to shop at Harbor Fright (as I call it) as their tools are cheap and tend to break - or damage what you're working on. Then you'll need to take your bike back to the LBS for surgery.

    Perhaps this may be a cynical point-of-view, but Harbor Fright tools, by and large, are garbage. There are a few exceptions though. My advice is to save up your money to by the BEST tools made for bicycles. Unlike Harbor Freight's offerings, you won't end up buying top-quality tools twice.
    LOL! I'll add the moniker: Horrible Fright.

    I work as a carpenter and will never buy a crap tool there unless I plan to use it once then throw away. I do buy some consumables there like SDS masonry bits.

    HF= Godawful crap. I've ended up hating the smell of cosmoline or whatever the hell it is hanging in the air there.

    End of rant.
    "I tell you, We are here on earth to fart around, and don't let anybody tell you any different." - Kurt Vonnegut jr.

  5. #5
    Senior Member
    Join Date
    Jan 2006
    Location
    Tucson, AZ
    Posts
    759
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Appreciate that info about the ammonia, newbie!
    Gotta love a forum like this - everybody can learn something!

  6. #6
    Senior Member
    Join Date
    Mar 2008
    Posts
    4,113
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by kinokokun View Post
    ...
    * Sheldon might be wrong when he says not to use a pipe wrench.
    No, but you're working from different premises. A pipe wrench is likely to gouge the post severely, even to the point of making it structurally inadvisable to reuse the freed post. it you have no intention of re-use, this concern of course goes right out the window.

    Quote Originally Posted by kinokokun View Post
    ....A pipe wrench, I found out, is designed to tighten onto a round pipe as you pull.
    ... And can easily do so to the point where the post caves in on itself, which isn't a problem either if you see the post as sacrificial. If you've grasped the post right where it exits the frame, squashing it will turn the situation from bad to worse.

    If it's a post with an integrated saddle clamp, grasp immediately below the clamp where the post is at its strongest.

    Quote Originally Posted by kinokokun View Post
    ...I was finally able to free my post by putting the pipe wrench on there, laying the bike over, and, using the ground as leverage against the end of the pipe wrench, standing on the whole thing so that the force of my weight downward turned the wrench.
    Great care needs to be taken with that kind of brute force approach, you can bend a frame/drop outs that way.

    Anyhow, congrats on getting it out.

  7. #7
    Keeping A Low Profile
    Join Date
    Oct 2007
    Location
    Atascadero, California
    My Bikes
    Specialized Hardrock Sport [1998], Dahon Speed P8 2007, 1994 Diamond Back Ascent and a couple of Schwinn Stingrays [one boys, one girls] from circa 1977.
    Posts
    160
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    [QUOTE=Apparently with steel frame and aluminum post you want to cool everything and then heat the frame because the steel will expand faster than aluminum (saw that on a post here I believe).QUOTE]

    The coefficient of expansion of aluminum is greater than steel, so the aluminum post will expand faster than the steel frame. Using heat with an aluminum/steel problem is usually a bad idea.

    DON
    The older I get the less future there is to worry about!

  8. #8
    Senior Member
    Join Date
    Sep 2001
    Location
    Montreal
    My Bikes
    Peugeot Hybrid, Minelli Hybrid
    Posts
    6,521
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by dwood View Post
    The coefficient of expansion of aluminum is greater than steel, so the aluminum post will expand faster than the steel frame. Using heat with an aluminum/steel problem is usually a bad idea. DON
    Unless the steel is on the inside - like pedals stuck in crank arms. Boiling water is not hot enough to damage a crank arm, but will cause enough expansion.

Posting Permissions

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