Removing stuck or seized seatpost?

Drill & then adjustable reamer & its out,just need to tidy the clamping bracket now.

Bravo! You sound well tooled-up.

I have the opposite problem to those in this thread:

I have a steel frame that takes 27.2 posts and a USE Alien titanium post which is 27.2 - but for some reason it only inserts about 6cm in and then is impossible to get down further.

Any ideas about what could be going on? I'm stumped.

it's been over 5 years since i started this thread and i got the fucker out today.
caustic soda and it didn't damage the paintwork happy days

Combining plusgas and ice and will know next week if it works!

Here's my method that destroys nothing but the corrosion.
I've just used it on a not very special 80's Bianchi frame with a stuck 27.2 mm Campag post that was well worth keeping.

BTW, I regularly use lots of caustic soda in another hobby, so am aware of its effectiveness but my method is easier / safer / non-destructive, therefore is to be tried first.
Do not rush the extraction process or start hacking and banging things about...take it easy. Let Physics and material science do the hard work!

Obtain a mug full of any 'light oil', around 300 ml; biodiesel, DERV, heating oil or even 50/50 cooking oil/white spirit.
With seat in place and BB out, invert frame and pour in via a funnel.
If unsure if the seat post is 'sealed' try a very small amount first to see if it dribbles out. If so, plug it by some means.
I then heat the visible bit of seat post with a plumber's propane / butane torch. Gently, so as not to burn the frame's paint or set things alight. Hold the seat tube mid way until it gets uncomfortable then turn off the heat. Don't do mad and reach the oil's flash point, obviously...
The thermal contraction of the dissimilar metals helps the thin, hot oil go South.
Leave for a couple of days minimum. Do some other bike jobs instead...
Empty oil out via the BB. Leave to drain over night. (You can re-use it as solvent for chain / parts cleaning)
Twist out seat post as normal, hopefully. If not, repeat the process, which has little 'hands-on' time.
HTH.

trying some Ammonia to get a stem out.
Fingers crossed it'll work...
it definitely stinks

a late addition too this, last resort/method at the shop I worked at was to cut the post 3 cm above seat tube and use a long hacksaw blade that was bolted to a length of strip steel this was used to cut a vertical cut down the inside of the seat tube, with care you would not cut the frame...when the cut was through ( mostly ) it would be possible to crush the seat post and remove it. This was done if all the usual soaking with chemicals ( wurth rost- off ) and gentle blow -torching had failed. We would'nt give up!

does anyone have any Plus Gas I can borrow in London preferably South East?

does anyone have any Plus Gas I can borrow in London preferably South East?

No but any thin oil will work..see my post above.

If no luck, I'll do it for you for a couple of beers. E11.

may give you a shout.
mine is a stem though? same process i guess though

Pretty much, yes.
Very worst case, it fractures. Then the bottom bit can be knocked through the fork quite easily.

Got a can if you can pick it up at from polo at SE1 tomorrow.

does anyone have any Plus Gas I can borrow in London preferably South East?

That would be amazing!
PM'ed

This is epic stuff.

Thought I'd share some knowledge I gained through getting a seatpost out this week

Hammering from the inside method:

http://img819.imageshack.us/img819/3985/7cf1.jpg

Take off your cranks and BB first

Get a length of threaded rod that is quite a bit longer than the seatpost you are trying to extract.
To one end attach a strong washer or plate which you have made fit loosely inside the seat tube. To the other end attach something with a bit of weight to it or something you can bash hard with a hammer or pull with mole grips. I slid a weighty bit of steel along the rod until it hit a nut at the end of the rod, providing a bit of momentum.

Before trying this method I had cut the seatpost in multiple places and managed to chisel out a section almost to the bottom with a masonry chisel and managed to move it further into the seat tube about half a mm as a result. Not much movement I know but it meant that it was on the way to being free. This method of forcing it from the inside then finished it off in just a few bashes. Here's the remains

http://img841.imageshack.us/img841/7595/5iwy.jpg

Worth a try before you start any kind of soaking or cutting technique I reckon!

morning all
Thought I'll ask some advice on this thread before i take drastic action (soaking ,cutting)I have stuck thomson seat post in a steel frame.Can anyone suggest ant solutions or a place where I can take it to be sorted .Cheers

Caustic soda is your best bet. Anything else is just delaying the inevitable.

Bike upside down, broom through rails of saddle. Stand on broom and twist frame. Worked for me with a stuck one after spraying wd40 everywhere and leaving it for a bit.

Apologies if this is elsewhere - has a scan of this thread but couldn't see anything similar.

I'm not sure if my post is actually stuck but I can't remove it because this:

Anyone had issues with a post like this? The top-section seems to have some slightly loose from the post so, when I had the saddle on and was trying to wiggle it out, just the top section was turning.

Left this fizzing away this morning.

Returned 9 hours later worried the whole bike would have been eaten. However the seatpost is still there and still fizzing, though it's changed colour. Keep waiting? Up the dosage? Try another method?

1 Attachment

Mr Seatpost

I've had a bottom bracket sat in Caustic Soda for nigh on a week now.

If it's fizzing, then it's still active: change the solution after a couple of days.

Can you get any down the seat tube to attack it from the other end?

How are you going to get the bit inside seat tube out?
Why don't you plug the seat tube and fill it from the BB shell?

There's only a small hole (c.1cm in diameter) from the BB shell into the seattube and I can't get a funnel in at the right angle to pour it in without getting it all over the place. I did this in a hurry this morning as I was heading out and I didn't have any kind of tube to feed it in.

I might experiment with that tomorrow, I was hoping that enough of it would dissolve that the rest would come away easily...too optimistic?

Stick a tube in the shell and the funnel in the tube.