Seized seatpost

oblongomaculatus

Any tips on how to unseize? So far I've tried twisting with as much force as I can manage, with absolutely no movement, and hitting the nose of the saddle with a mallet, which moved it about 2cm in one direction, then back to being straight by hitting the other side, all of which left it no looser. I've also tried dribbling lemon juice into the frame through the little hole where the seat clamp grips, though I'm not sure much penetrated. Someone at work suggested Coca cola, which sounds bizarre. The frame is aluminium and the post is carbon clad alloy. I don't actually need to remove it at the moment; I was just thinking of experimenting with seat height, so I don't want to do anything which might damage the frame.

Anonymous

oblongomaculatus wrote:

Any tips on how to unseize? So far I've tried twisting with as much force as I can manage, with absolutely no movement, and hitting the nose of the saddle with a mallet, which moved it about 2cm in one direction, then back to being straight by hitting the other side, all of which left it no looser. I've also tried dribbling lemon juice into the frame through the little hole where the seat clamp grips, though I'm not sure much penetrated. Someone at work suggested Coca cola, which sounds bizarre. The frame is aluminium and the post is carbon clad alloy. I don't actually need to remove it at the moment; I was just thinking of experimenting with seat height, so I don't want to do anything which might damage the frame.

You stick lemon juice down the seat tube then call using coca cola bizarre?

I would just get a LBS to remove it and then give it a clean and relube before inserting it again. Some things can be done at home and some things can make you end up breaking your bike if you aint careful - which (no offence) you dont particularly sound at this moment,

keef66

Lay the bike down and run some very hot water over the seat-tube. The Alu should expand and give you a bit of wriggle room. Don't overdo it or the seatpost will get hot and expand as well.

If you do get it out, thoroughly clean the inside of the seat tube and the outside of the post before reinserting it using some carbon assembly paste.

I redo my seatposts every 6 months or so; one carbon post in an alu frame, the other an alu post in a carbon frame. Use carbon assembly paste for both.

keef66

Lemon juice contains citric acid and coke citric, phosphoric and carbonic acids, so they will both have an effect on aluminium oxide. Trouble is, they are neither of them really strongly acidic, so any useful effect would take a while and a lot of reapplication.

With a post stuck in an alu frame, heating the seat-tube can be a lot quicker...

oblongomaculatus

Maglia Rosa wrote:

You stick lemon juice down the seat tube then call using coca cola bizarre?

Yeah, lemon juice did sound a bit odd when I read of it somewhere, but I figured it might be worth a shot as it's acid and might dissolve any corrosion. I wasn't surprised as it didn't work. Coca cola sounded even weirder as it's mainly sugar. So far I've been cautious, I think; I wasn't hitting the saddle with much more than a brisk tap.

I've thought of using heat, from a hair drier maybe but haven't tried it yet as I was worried that might melt the paint.

I might try the hot water thing this weekend, Keef66. Thanks.

svetty

If it's moving as you describe it is likely a matter of heat/cola and gradually working it free. It's when they won't budge at all that things get serious

lpretro1

If all esle fails this guy is brilliant: http://www.theseatpostman.com/

nicklouse

read the 14 (I think it is now) ways to remove a stuck seatpost on Sheldon Browns web pages. link below.

shaw8670

Use a fairly wide and very coarse round file. File 2 or 3 sections until the seatpost gets this, then gently chisel through them and it'll start breaking/peeling away. You obviously need to saw the top off first. Sawing can be harder and can just leave you with 3 seized sections and no way to lever. On an aluminum frame don't worry too much if the top part gets a wee bit splayed out, the tightening of the collar will sort it out. I recently did this on a Kinesis that was severely seized. I'd say to do a bit at a time. It can be a bit disheartening if you set about the task in one go!