[Closed] help! stuck seat post 🙁

Put it into a workmate (the saddle) and use the frame as leverage. This will ruin the saddle - but move the most stubborn seatposts.

you could try filling up the seat tube from the hole in the bb shell with wd40 (turn bike upside down) and leave it a few days

Boiling water. Penetrating oil. Tapping the post with a hammer to try and break the bond.
Then, when that fails
Post in a big vice and use the frame as a lever.
If you can't get a vice then a drill hole through the post and pass a bar/big screwdriver through it to work as a lever.

As a man who had this problem once, I tried most of above before shamfully going to lbs.
They put a broken saddle on ,upside down in vice and easy peezee post came out.
I was too soft and it just need an experienced heave

It's been a while, but what material post into what material frame?

I tried all of the above including a huge vice at work and enormous force - none worked (ally post in steel frame).

The only remaining method without damaging the paint was cut off the post, then remove with expanding reamers. It took about 3 hours in total, working up through full adjustment range in 3 sizes of reamer. Quite a lot of energy and sweat was involved....... It produced about 2 mugs full of swarf until the final skin of the post peeled out.

Industrial freezers or liquid nitrogen also work, but it was a brazed frame and I was bothered about breaking joints due to brittle fracture.

Bike upside down, bb out and pour ammonia in.

http://www.sheldonbrown.com/stuck-seatposts.html

I have heard that coke works too.

How long to leave the ammonia in the upside-down frame ?

I used caustic soda (sodium hydroxide).

For something so incredibly dangerous, I was a bit amazed that you can just walk into a garden centre and buy it for tuppence.

Remove the bottom bracket, bung up the BB shell with an old inner tube and then pour in hot concentrated caustic soda.

USE EYE PROTECTION!!!!

Seriously, this stuff is lethal! Rubber gloves also essential unless you are tired of your own skin.

You get a mixture of hydrogen gas, steam and left-over caustic soda frothing out of the tube. Not nice.

A couple of nights of doing this and it came out (well, disintegrated).

(Annoyingly, my previous attempts to remove the tube using brute force had damaged the frame so I'm still working out what to do with it).

EDIT: it's not kind to paint, but not as bad as you might imagine. Probably if you put tape over the paint it would be fine.

steel frame, aluminum (i think - its a thompson seat post)

according to sheldon, blow torching the frame wont work, cos aluminum heats up much quicker than steel, so id just end up expanding the seat post instead.

[url= http://singletrackworld.com/forum/topic/the-real-thing ]Coke[/url]

Caustic soda works be careful you don't get it on the paint work because it will strip The paint right off.

I had an alloy post bonded in carbon. Tried all kinds but possibly the snowboard/ski base cleaner helped the most. Basically a citric acid solution. Then required a hell of a lot of effort constantly trying to rotate it or the frame. Gave me aching arms and it made a hell of a noise squealing as it eventually rotated. Probably would have been much easier with a vice though. Since then, don't leave alloy and carbon mixed together as it does react and bond in certain conditions, so I remove the post when not in use. Also a smearing of carbon assembly paste helps prevent it bond. Can be used for alloy in alloy also and helps reduce clamping force required.

Not sure on steel and alloy, but a similar reaction to carbon and alloy could occur I guess. It's a galvanic corrosion and occurs more with dissimilar materials.