Removing a seized seatpost

by Otis Bragg   July 4, 2014  

The seatpost on my Allez is well and truly seized-I took it to my LBS and they could do nothing with it. At Wits End I have tried all the different approaches except for sticking it in a bench vice- unfortunately I don't know anyone who has one (although to be honest I don't think it will make much of a difference anyway). The heating/freezing approach doesn't work because both post and tube are aluminium so expand and contract together. I've tried penetrating fluid (loads of it) and every other suggestion I can find, so it looks like I am going to have to sacrifice the post so that leads on to my questions-

What is the best way to cut the post so that it can be removed (ie how many cuts and in what direction?)
What is the best thing to use? I have hacksaws etc but someone did mention a Dremel with a metal cutting bit. My big fear is cutting down to the seat tube and being unable to cut enough of the post still in the frame to remove it.

Simply put I don't want a cut seat post that still won't come out!

Any suggestions as to cutting (or any radical new approaches I may not have tried yet) would be more than welcome.

Thanks
Marty

12 user comments

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Oh fun and games.....

If you have tried EVERYTHING possible and the LBS have tried it, then it is a case of cutting it out.

I'm trying to think, does the allez have a small hole underneath the seat clamp?

That is your best bet for getting it out. There are MANY ways to get it. I would go on as low as you can in the seatpost with a drill. If the frame does not have a little notch then go in as close to the frame as possible without touching the frame.

Start with a small drill bit, put a hole in BOTH sides and go up in size. Until a point you can put a something sizeable through, a like piece of round bar.

Get someone to sit on the frame to keep it held down, while you take each end of the round bar or similar and twist and turn it, until the seatpost comes loose.

If this does not make sense. I could make a simple video for you, I have a couple of old frames with stuck seatposts in the workshop ready to be scrapped.

Gkam84's picture

posted by Gkam84 [9201 posts]
5th July 2014 - 1:26

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Thanks Gkam,
Yeah there is a slit with a small hole under the seat clamp-I've been spraying penetrating fluid in there as well as around the top of the post and, after turning the bike upside down, down through the hole for my bottle cage. Drilling is something I have been thinking off-now to find a suitable metal bar...

Otis Bragg's picture

posted by Otis Bragg [142 posts]
5th July 2014 - 1:36

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Always try and twist it out, don't try and pull up or push it down.

Once you get it twisting, give it a pull up, if it comes out first time, prefect, if not, put some oil down and keep twisting.

If you have tried this already with the saddle, fine, but with a bar through the seat post as close to the frame as possible, that will give you much better torsion compared to the saddle method.

Gkam84's picture

posted by Gkam84 [9201 posts]
5th July 2014 - 2:42

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Slide hammer attached to the top of the tube. I used one on a seized motorcycle suspension linkage. Nothing would remove a seized shaft, heat lubrication or prying. But fitting a slide hammer in the direct plane of pull, slowly worked. A completely rusted shaft removed after 30 mins of work

Get them from any decent automotive hardware centre for not alot.- the company that sells clarke products Smile

posted by CXR94Di2 [389 posts]
5th July 2014 - 16:05

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Gkam84 wrote:
a bar through the seat post as close to the frame as possible, that will give you much better torsion compared to the saddle method.

Really? Wouldn't have thought a seat post would suffer from wind up, irrespective of length of post exposed. (On other hand might break clamp rails.)

posted by surly_by_name [213 posts]
5th July 2014 - 17:42

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surly_by_name wrote:
Gkam84 wrote:
a bar through the seat post as close to the frame as possible, that will give you much better torsion compared to the saddle method.

Really? Wouldn't have thought a seat post would suffer from wind up, irrespective of length of post exposed. (On other hand might break clamp rails.)

Normally a seat post wouldn't suffer from any kind of torsional force. But everything else has been tried, the LBS has tried it aswell. So I bet it has been in a vice a couple of times there, depending on how tight they had it in a vice, I wouldn't trust putting stress on it to far from the frame.

This kind of thing will happen
http://saarf.net/2012/05/06/messy-master/

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posted by Gkam84 [9201 posts]
5th July 2014 - 18:04

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Had this before. Solved it by sawing off the post about 50mm above the seat tube top. I made a handle for a power hacksaw blade out of 30mm dowel, taped together. Then htfu and cut the tube lengthways down the tube! Took about 1 day, lots of penetrating fluid, lots of effort, then got a set of molegrips and twisted the end round. Nothing's ever easy,but it came out!

posted by GrahamF [15 posts]
5th July 2014 - 18:58

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Otis Bragg's picture

posted by Otis Bragg [142 posts]
5th July 2014 - 22:16

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Talking of penetrating fluid, WD40 is pretty useless, Plus Gas is as good as it gets.

All Campag

posted by Flying Scot [794 posts]
6th July 2014 - 13:50

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Have you tried tapping it down a little to free it? I have had to do this a few times on restorations, cut the post near the top so you can get a piece of broom or dowel for extra support, get a good grip with vice grips, gently tap down while twisting.

As far as the cause of this, assuming its both aluminium parts fused together by oxidisation, if I remember Phosphoric Acid will dissolve it, but I dont know what else it will do, but coke has Phos as an ingredient, you could try a bit if you get some movement, dont know if it will be strong enough, but you have nothing to loose

posted by jason.timothy.jones [303 posts]
7th July 2014 - 9:01

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Jason....NEVER tap down on a seized seatpost that you know nothing about.

There are a few reasons it could be seized, but most are caused by two things. Inserting it wrong or forcing the wrong size in.

So if you tap down and it is the wrong sized post...you are going to end up splitting a frame

Gkam84's picture

posted by Gkam84 [9201 posts]
7th July 2014 - 9:44

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Gkam84 wrote:
Jason....NEVER tap down on a seized seatpost that you know nothing about.

There are a few reasons it could be seized, but most are caused by two things. Inserting it wrong or forcing the wrong size in.

So if you tap down and it is the wrong sized post...you are going to end up splitting a frame

Nothing mentioned wrong sized post, if this were the case then there are more problems.

I was offering a suggestion that has worked for me several times, no need to be such a dick in your response

posted by jason.timothy.jones [303 posts]
7th July 2014 - 11:05

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