Steel Frame + Alu steatpost= Headache

[wheres_my_beard]

I seem to have discovered tooless wielding... my seatpost in solidly stuck in my frame.

I have tried brute force to twist the post using a large allen key clamped in the seat clamp and a some handlebars for extra leverage, and even with a dose of WD40, nothing has shifted. I have tried prying the collar open with flat screw driver. I have even tried kicking the bike and swearing at it; even that didn't work.

Anyone got any wisdom to help me solve this problem?

 

[Smokin Joe]

Find something like a packet of frozen peas in the freezer and wrap it round the alloy post, at the same time put a towel soaked in hot water round the top of the seat-tube. The resulting expansion/contraction may well be enough to break the seal.

 

[albion]

Supposedly aluminium shrinks more than steel so put some ice cubes in a bit of tube/baloon and stuff it down.

 

[biggs682]

how annoying is it when this happens , i broke a hair dryer warming up frame trying to release a seat post before , and it still didnt work

 

[Amanda P]

The story of a couple of stuck seatposts is recounted in this thread. The good news is that they both came out in the end.

Things to try:

• Powerful twisting. If you can fix the seat post in a really stout, immovable vice, and twist the bike, it may get it moving.
• Percussion - with the bike frame resting on something immovable and non-bouncy (so, not its tyres, not a wooden floor), hit the seat post hard. No, much harder than that. You'll be knocking it into the frame, not out of it, but again, once it's moving it may be persuaded to move out as well as in.
• Heat/cold. You want to expand the frame or shrink the seatpost. So hot water on the frame might help, or ice or something cold inside the seatpost. Counterintuitively, heating the seatpost might help too - anything that cracks the 'weld' between it and the frame may get it moving. So a hot air gun on the seatpost might just help, then try again when it's cooled down again.
• Caustic soda. This did the doing for me. It's sold in ironmongers and DIY shops as a powder or pellets, which you make up into a solution (carefully!) for cleaning drains. Take care with it and follow the instructions - it's nasty stuff. If you can figure out a way to introduce it to the interface of frame and seatpost and keep it there, it should dissolve the oxide that binds them together. (Eventually, it would dissolve the seatpost too). My seatpost was fluted, so I just kept squirting a little soda solution down the flutes. You might need to turn the frame upside down and fill the seat tube up with the stuff if yours isn't fluted. You might need to drain and replace the solution periodically - the oxide seems to neutralise the solution after a bit. It stops fizzing anyway.
• Persistence, combining any or all of the above until something gives.
• Bike shops have various techniques and usually better tools than you have. Some of these techniques are fairly brutal, and they'd probably rather you weren't watching. Maybe you'd rather not be there either.

There's an excellent chance that the seatpost will not survive the operation. Be prepared to sacrifice it if necessary. But you'll want to save the frame, and the paint on it, so take care with heat guns and hitting things, and think about what you're doing and what the consequences might be before you do it.

In future, grease the seatpost before fitting it, and remove, clean and re-grease it every year or so, or after a salty winter.

 

[Amanda P]

Oh, re-reading that thread, I see that in the end Zippy extracted his seat post by patiently sawing a groove in it from the inside outwards, along its length. But only after he'd tried (extensively) the chemical, mechanical and thermal approaches.

Illustrated account of my own adventure with a seatpost here: https://www.cyclechat.net/threads/f-seat-post.25842/post-512147

 

[wheres_my_beard]

Well, I'm having some mixed success.

I have managed to twist the seat post around about 10 degrees. WOO HOO!

However it will go no further.

The price of this modest achievement is:
- lots of dents on the top of the seat clamp (from whacking it)
- a totally bent handlebar (for leverage)
- a destroyed saddle (used as a pivot)
- paint damage around the seat post clamp bit on the frame (from heating up the frame)
- peas all over the yard (from cooling the seatpost)

Luckily I have the morning off work tomorrow so I'll visit my LBS and hope they can work some magic on it, and I'll see what seatposts and grease they have in stock while I'm there.

 

[wheres_my_beard]

The LBS has had the bike for 24 hours now. After a flurry of activity yesterday when I took it in and the shop was quiet, they had no success in budging the post, but did manage to crush part of the post while trying to twist it in a large vice.

It has been soaked in TFT over night, and they are apparently applying more at regular intervals, but they don't seem to have any immediate plans to do anything else for the time being.

I'm not sure what TFT is to be honest, and I have no idea if its the best thing to be doing right now...?

 

[wheres_my_beard]

Anyone else had to have there stuck seatpost milled out?! Thats what my lbs are having to resort to in order to get it shifted. Sounds like they have tried everything possible apart from using chemicals, and it is still totally bound inside the seat tube.

Luckily they arent going to charge for the labour time they have already put into it, but they don't know how much this milling will cost yet; hopefully not too much.

 

[Zoiders]

I did once many moons ago have a second hand Reynolds Steel Raleigh M-trax with the space-shuttle glued lugs.

Raleigh didn't fit ally posts to these frames, it came supplied with a thinly drawn Reynolds steel post with what looks like a ti-nitride finish.

I still have it, I now use it on another bike, it never seizes.

 

[wheres_my_beard]

Awesome. I wish mine had come with a steel post.

 

[Holdsworth]

Bah not this monumental headache again. My 531 road bike managed to get its alloy seat post stuck after riding through last winter. I found out that it was stuck in too low for me so I stopped riding it. Brute force and WD-40 was no help in budging it and I was certain that I'd have to turn to dissolving the seat post with caustic solution.
In the end though I took it to my LBS and the put the bike upside-down with the seat clamp in a vice, using the frame as a lever the seat tube was twisted slowly out of the frame and promptly replaced with a new, properly-greased stem. If you aren't attached to the seat post I'd recommend doing that first.

EDIT: Sorry, just read your other post about the LBS, disregard my advice, it worked well for me though.

 

[User482]

My LBS got mine out by applying heat to the seat tube and levering the seat post in a vice. This was an option only because I was having the frame repainted anyway, and the seatpost was scrap afterwards. My efforts with hammers, levers, vices and WD-40 had all failed.

The best way to apply caustic soda or penetrating fluid is from the bottom bracket shell - there should be a hole at the bottom of the seat tube. This only works if your bottom bracket isn't seized as well.

 

[Globalti]

I read somewhere that cola will also dissolve the aluminium oxide; it contains phosphoric acid.

 

[wheres_my_beard]

Well, my LBS still hasn't managed to get the engineers to do the milling out of the seatpost (as a "favour" from the shop guy who apprenticed with them). There is virtually nothing left showing of the seat post now that they have tried twisting with vices and sawing it out.

Do I have any other options? I'm reluctant to pour corrosive chemicals inside my frame if I'm being honest.