How do I remove a bike post when it seems forced into the slot?

Question

I just bought a used bike, the bike post is too large for the hole that it fits in on the Schwinn mountain bike. It appears jammed in, I've tried to pull it out without any luck. Is there any tricks to getting this out? Wd-40 or something? Thank you.

Answer 1

put a cheap seat that u dont care about on the post and get it as tight as possible on the bike where the post goes in there is a cut out slot there might be 2 the tightener itself may need removed which should be directly over this slot but put a flathead screwdriver in this slot and try widening this a little then apply some wd 40 on the base of the post then u need to turn the seat post using the seat and lift while u turn

Answer 2

Use a penetrating oil which WD-40 is not.  If you can replace the post, use a pipe wrench or other tool to turn the post as you pull on it.  (Teeth marks will be left and they may be quite deep into the metal.)  You might also clamp a pair of vice-grips on the post and use hammer blows as you turn it.

Answer 3

If the seatpost has been forced in I'm afraid you are out of luck.

Your only viable option is to cut the seatpost off as close to the frame as you can, then take a hacksaw blade and slice the post along it's length. You can then grab it with a pair of vise grips and "roll" it out.

Answer 4

The question is whether the seat post is physically jammed in the seat tube, or if they have oxidized and gotten stuck?

First off, if this frame is aluminum and a too big seat post was forced into the seat tube, I doubt it is worthwhile to attempt to salvage the bike.  Aluminum is not a forgiving metal.  Rather than stretch, aluminum cracks.  You may not be able to see the cracks but they are there and ultimately the frame is going to fail in the vicinity of the seat tube.

If part of the problem is caused by rust, and the post and bike are made of steel, WD40 should help.  WD40 is a decent penetrating oil.  Liquid Wrench, however, is even better.  Put it on from the top and if you can take the bottom bracket out, put it in from the bottom.

If the bike and seat post are made of aluminum penetrating oil will not help.  For oxidized aluminum you need to use some ammonia.  Again, apply to the top and bottom and let it do the trick.

Once the oxidation is gone, you'll need all the leverage you can get.  Assuming you don't want to use the seat post again, you can get on it with a pipe wrench or vice grips.  

You can also try heating the frame with a blow dryer.  The key is just hitting the frame long enough to warm it and cause it to expand, but not so long that the seat post warms up and expands, as well.  This technique works better on steel than aluminum because aluminum is so effective a conductor.  Be real careful not to soften and/or blister the paint.  If you are softening the paint, you are heating way too much.

If all else fails, cut the seat post off level with the top tube.  Then take a hack saw blade and carefully cut through the seat post lengthwise.  It'll take a long time especially if the seat post is steel.  Go slow and check often to insure you are not cutting through the post and into the frame!   With luck you'll only have to make one cut, but be prepared to have to make two cuts and remove the post in pieces.

Hope this helps.