Stuck seat post?


Retro Newbie
Hello I just got hold of an old vintage road bike that might or might not become a project for the months to come.

To my surprise I notice what it seems like a stuck seat post inside the frame.

However it is at least 9-10 cm deep inside the tube and does not prevent the new seat post from sliding in. My questions for you:

a) how the heck have they managed to do that??
b) is there a way to remove it? I‘ve seen plenty of advice on how to remove a ‘traditional’ stuck seat post but in this case I cannot tell whether it will be more or less difficult!

I included some pictures for reference! Thank you!


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Senior Retro Guru
Caustic soda method. The tube will need reaming as it has deformed from previous attempts at removing the post.


Retro Wizard
I agree, no way you'll ever get a tool in there to remove it. And reaming will be essential to get any replacement seatpost to stay put.


Senior Retro Guru

The tube looks deformed which will continue to present seatpost problems.
Edit - Someone above has already said that, must read properly next time


rBotM Winner
PoTM Winner
Unless it is sentimental to you or some kind of rare frame Worth the time & effort... personally I wouldn’t bother & look for something else....of course you can experiment by chucking down various chemicals down the seat tube & see what happens :)


Kona Fan
Probably not worth it with the deformities around the seat tube. But caustic soda is an entertaining experiment to get rid of any nasty aluminium. I recently used to remove a very thick and long stuck seat post, what you've got in there is like a light lunch for the caustic soda. Pour it in and listen to the beautiful sizzle while you crack open a beer or two. Therapy. Just remember to wear PPE and don't drink too many beers.


Dirt Disciple
Caustic soda will only work if the seatpost is made of aluminium.
Just reaming would leave you with no lug wall.

Get a long hacksaw blade and attach it to a wooden handle and approach the task slowly and carefully.
To reform the seat lug support it properly and hammer it gently and gradually with a hardwood drift and something like a one inch socket inside it, changing the size of socket as the shape returns. Or put it in vice grips and form it from within.


Retro Newbie
Re: thank you

Thanks guys a lot of useful (and entertaining) opinions!

My view at the moment:

After a quick research on the internet caustic soda method feels a bit too dangerous, plus I’m not sure if it’s aluminium or steel. Maybe I’ll do it if I get bored and just to see what happens. At the moment it is causing no problem so it can stay there.

Reaming: at the moment the seatpost is pretty solid but will probably give it a try if not too complex. I would be great if anyone has got a link to a nice tutorial / description of the process

Thanks and have a great weekend!