Stuck Seat Post

cleeve hill reject
cleeve hill reject Posts: 426
edited March 2009 in Workshop
An age old question with a twist, I've bought a nice steel framed Bianchi but it seems that some mug has put too large a diameter seatpost into it and it is completely stuck fast - you can feel the bulge in the tube where the post is jammed in and the paint has split a bit as a result of this. I've tried drilling through it and getting a bar on the end of an allen key but it won't shift, anybody have any ideas that don't involve heating up the tubes and ruining the paintwork?



  • You're not having much luck with your used frame purchases are you? :wink: What's happened to your carbon frame of dubious provenance?

    May I be the first to suggest tipping the frame upside down and pouring coke into it (via the BB)? This isn't the ideal solution I know, and is best utilised as a last resort for seized components, but I'd love to know if it works! Failing that, take it to framebuilder and let him worry about it would be my suggestion!
  • Rockhopper
    Rockhopper Posts: 503
    Chances are that even if you get it out you'll find that one of the right size will be too loose now that the other one has distorted the seat tube.
  • balthazar
    balthazar Posts: 1,565
    If the seatpost remaining in the frame is short enough, then you can use a large hacksaw blade to cut through it, slowly and with much effort, along its length. You don't need the cut to go fully through everywhere - 95%-ish will be good enough, favoured toward the top, when you can get a big Stilson and other imaginative tools on it, with the intention of collapsing it radially, into itself.

    These kinds of procedures take forever and are commonly avoided in bike shops because nobody would ever pay the labour. There's no reason why it won't work, however, as long as you're prepared to give it the time. Anybody who ever restored an old car will know the sort of thing required.

    If you need to get a bigger seatpost to fit the swollen tube then do so. It isn't a complicated interface, demanding of precision components: as long as the seat stays in place, then success.
  • Nelson, you're right, I'm not having much luck, the carbon frame is being ridden and is getting questions as to its origin everywhere I go, no one has been able to identify it yet!

    Balthazar, that method sounds like the only one that might work, if I cut the post then can't get the post out the frame is a wreck though, I might just have to get hold of a saddle that will add a little extra height and put up with it, that or find someone to buy it who has the perfect inside leg measurement! Thanks for the advice!

  • nicklouse
    nicklouse Posts: 50,675
    you have a few options.

    Cut a slot or a few so that the seat tube can be folded in to remove the pressure and then removed.
    and then shim the seat tube to fit a new size.

    Go to a machine shop and get them to ream the seat post out to a usable size.

    etc etc.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown