How to remove seat post stuck in frame?

[PaulB]

My carbon fibre seat post is totally welded in to my aluminium frame. It is at a perfect height to ride and will not go down by even one millimetre and no matter how much force you put on it, it will not come out of the frame. I need to get it out so I can pack it for a foreign trip next month so how can it be done? I don't mind replacing it so I'm happy to saw it or something. I've also tried heating the frame so it may expand but to no effect.

All suggestions welcome.

 

[iLB]

i wouldn't go heating carbon fibre too much...

soak the area in wd40 (other multi purpose lubricants are available) and leave it for a few hours, then try again, if it's still not working then give it another wd40 bath...?

sawing it off wouldn't do much good as you would still have a piece wedge in the seat tube...

 

[Norm]

Does it need to come out for packing, or can you just remove the saddle?

I think most answers are in this thread. Are you happy to write off the seat post?

 

[PatrickPending]

Mmm heating didn't work try some of the suggestions in the link but its a different case with alloy posts in steel frames than yours - chances are it just needs a good twist

 

[accountantpete]

In theory a "sausage" of ice packed down on the inside of the carbon and heat applied externally to the alloy seat tube may be worth a go.

 

[JensR]

I had exactly this problem and fixed it a few weeks ago by pouring boiling water on the outside of the frame so that it expanded (this worked fine - I think you need to get the metal to hold the heat for a bit, not just get it hot for an instant). But if that doesn't work, I've heard of everything from taking the bottom bracket out and pouring cola down the inside, to using a hacksaw on the seatpost.

In my case it turned out to be galvanic corrosion building up inside the frame, I suspect caused by a build up of dampness after wet rides.

After I got the post out, I did quite a bit of scraping with a wire brush and screwdriver but some of the material wouldn't come off. I put some carbon fibre assembly paste in to hold things but I don't know if copper-slip would be better to prevent the seizing - I've heard that it also can react with the aluminium. Even so, the seatpost now almost glides in and out compared to before it got stuck, so I will definitely be checking inside the frame at least every month.

 

[Globalti]

For an ali post stuck in a steel or ali frame Sheldon Brown recommends sacrificing an old saddle by fitting it to the post then fixing it in a vice and twisting the frame to get the leverage.

Your carbon post is stuck because the steel frame has oxidised and iron oxide takes up more space than the original metal, which has wedged the post in tight. There's no chemical bond there so a good hefty twist using the Sheldon method ought to shift it.

 

[TheDoctor]

For an ali post stuck in a steel or ali frame Sheldon Brown recommends sacrificing an old saddle by fitting it to the post then fixing it in a vice and twisting the frame to get the leverage.

Your carbon post is stuck because the steel frame has oxidised and iron oxide takes up more space than the original metal, which has wedged the post in tight. There's no chemical bond there so a good hefty twist using the Sheldon method ought to shift it.

According to the OP it's an aluminium frame.

 

[JensR]

Aluminium reacts with water and the result is similar to steel rusting - there is no bond between the carbon fibre and aluminium, just a "wedging" effect, so Globalti is in essence correct about twisting it out.
It is worth noting that the seatpost will probably come out very scratched but should be structurally sound.

Jens

 

[RecordAceFromNew]

Assuming aluminium oxide is the cause for the carbon seatpost getting stuck, then perhaps one of these is worth trying?

 

[Globalti]

Yeah, whatever - aluminium oxide also takes up more space than the metal.

 

[PaulB]

I tried loads of the above and nowt worked so I took it into an LBS and they are going to give it a bath (ahhh, bless!) in WD40 for several hours and then giving it a try. I'll let you all know the outcome.

 

[PaulB]

He's done it and I can collect tomorrow. He bathed it in WD40 and got an implement in to increase the saturation then brute strength from several of his staff got it out!

 

[Moodyman]

Note to you Paul:

Anti-seizure grease next time as a preventative measure.

 

[PaulB]

Note to you Paul:

Anti-seizure grease next time as a preventative measure.

Cheers, big ears