Aluminium seatpost seems stuck in steel seat tube - any suggestions for removal?

[Oxford_Guy]

Hi - I tried to remove my black anodised aluminium Ritchey Comp seatpost (one of these) from the steel seatpost tube of my Hewitt Cheviot tourer today, only to find to my dismay that it seems to be completely stuck - it won't budge even a mm. :-(

Admittedly I've probably not removed the seatpost for about 3 years, when I bought the Ritchey Comp one, after the original Kalloy seatpost was stolen (along with the Brooks Imperial saddle that was attached to it...), but I'm going to need to be able to remove it before the summer, as am probably going to have to box the bike up for air travel for a planned cycle tour and it will need to come out!

The bike is used as a year-round commuter, as well as a touring bike, so is out in all weathers.

Any suggestions for how I might be able to get the post out? It seems absolutely stuck. BTW I don't care if the seatpost gets destroyed in the process, but it must come out!

[Oxford_Guy]

Am even considering using the services of "The Seat Post Man" (http://theseatpostman.com/service/ ), though that would cost at least £69.99 - though if it would mean I could get the post out without damaging the frame. I'd be prepared to pay that.

[igauk]

I presume you've tried soaking in Plusgas or the like? Can sometimes take a few days of repeated application. Gentle heat, e.g. hairdryer not blowtorch might help.

[hatler]

Where's that thread about dissolving the seatpost out?

[hatler]

Found it.

[Oxford_Guy]

I presume you've tried soaking in Plusgas or the like? Can sometimes take a few days of repeated application. Gentle heat, e.g. hairdryer not blowtorch might help.

I've not tried anything other than twisting/pushing/pulling the post by hand, in case I made the problem worse or damaged the (expensive 725 chromoly) frame... That's why I'm asking here for advice before I do something I shouldn't...

[Oxford_Guy]

I presume I should have used some sort of anti-seize product when I originally fitted the post? What is generally used?

[handcyclist]

I presume I should have used some sort of anti-seize product when I originally fitted the post? What is generally used?

Anti-seize grease, better quality = longer between check removal and refitting.

[Wowbagger]

Are we to assume that the seatpost is not broken?

[handcyclist]

Any suggestions for how I might be able to get the post out? It seems absolutely stuck. BTW I don't care if the seatpost gets destroyed in the process, but it must come out!

Your problem is probably that the aluminium and the steel have become chemically bonded (sometimes called 'cold welded'). Soaking in lube will not help much in this situation.

Rotational force (ie twisting) is better than hitting it in terms of benefit/risk of damage. Clamp the seatpost firmly in the biggest vice you can get access to, with the frame upside down, and twist the frame. Steel frames can take a lot of force if you push at the headtube.

If that doesn't work, a lot of heat to the seatpost only. You may lose a little frame paint if you get it really hot.

If that doesn't work, it can be cut out, but you might want to stump up the £70 for someone else to take on that risk.

Good luck!

[Canardly]

The last time I had this problem I was lucky in that the local LBS managed to get it out with brute force (took two of them) but this was a steel frame. Process destroyed the post. Liberal coating of copper ease/slip thereafter.

[Torslanda]

I can vouch for 'the Seatpost Man' and have used his services twice. Both happened to be stem related - stuck quill stems - but that's by the by, has a fully equipped workshop and is a precision engineer.

a method that has worked for me in extremis is to fit a piece of 2x2 into the dropouts, (having stripped the frame completely) and screw two long pieces of 2x4 together either side of the frame, coming to a point beyond the head tube and joined together at the drop outs. Effectively bracing the frame end to end and protecting the dropout spacing.

You then need a big vice - the motorbike shop next door to me has an 8" Record engineer's vice which is welded to a steel bench which in turn is built into the wall - trap the seatpost and turn the frame back & to. a friend to help would also be an advantage. You could, of course, dispense with the wooden bracing but you're risking distorting the frame.

A friend who is a science teacher tried the caustic route. Three weeks to dissolve a Kalloy el-cheapo post.

TL/DR Hard work or pay the man.

[Oxford_Guy]

I can vouch for 'the Seatpost Man' and have used his services twice. Both happened to be stem related - stuck quill stems - but that's by the by, has a fully equipped workshop and is a precision engineer.

a method that has worked for me in extremis is to fit a piece of 2x2 into the dropouts, (having stripped the frame completely) and screw two long pieces of 2x4 together either side of the frame, coming to a point beyond the head tube and joined together at the drop outs. Effectively bracing the frame end to end and protecting the dropout spacing.

You then need a big vice - the motorbike shop next door to me has an 8" Record engineer's vice which is welded to a steel bench which in turn is built into the wall - trap the seatpost and turn the frame back & to. a friend to help would also be an advantage. You could, of course, dispense with the wooden bracing but you're risking distorting the frame.

A friend who is a science teacher tried the caustic route. Three weeks to dissolve a Kalloy el-cheapo post.

TL/DR Hard work or pay the man.

I'm definitely gravitating towards getting a professional to remove the seatpost, though as well as the £70 fee, there's also going to be the cost of sending the bike there by courier there and back (I'm in Oxford, Seat Post Man is in Chorley in Lancashire, I also don't own a car...).

[Feanor]

Where's that thread about dissolving the seatpost out?
Found it.

There was another thread, called something like 'how I cooked my bike', with pictures of a frame clamped in a workstand over a cooker, with the seatpost in boiling Caustic Soda.

I can't find it now.

[Roy]

When I had a similar problem my LBS suggested pouring boiling water over the seat post / frame several times to get it hot then hit / shock the seat post as in the previous post. I had to do this two or three times with a few squirts of WD40 in between. It worked with no damage to the frame or the seat post.

[giropaul]

Coke ( Coca Cola full fat) has been known to work ( acid attacks the alloy bonded to the frame).

[Torslanda]

Where's that thread about dissolving the seatpost out?
Found it.

There was another thread, called something like 'how I cooked my bike', with pictures of a frame clamped in a workstand over a cooker, with the seatpost in boiling Caustic Soda.

I can't find it now.

The only one like that I can remember was using alum to remove a broken steel bolt from an alloy frame . . .

[igauk]

PlusGas can work on steel and aluminium, not just steel/steel. You could also try Loctite Freeze & Release (cools down to -40 or something). For the cost both of these are worth trying before anything else more expensive/invasive/destructive.

[zigzag]

Where's that thread about dissolving the seatpost out?
Found it.

There was another thread, called something like 'how I cooked my bike', with pictures of a frame clamped in a workstand over a cooker, with the seatpost in boiling Caustic Soda.

I can't find it now.

The only one like that I can remember was using alum to remove a broken steel bolt from an alloy frame . . .

more accurately i've used this method to remove a broken tap (hardened steel), which i used to remove a broken bolt..

but this is not suitable for a stuck alloy seat post!!

[andyoxon]

My alloy seatpost is also stuck very fast in steel frame.    Unfortunately I inserted it years ago, without copper slip, which I routinely use these days.  Although it was one of those extra long posts I cut it to match the fluted post I was taking out, so hacksaw blade route for removal may work - when the time comes (not yet).  Makes me think, that testing this when buying a second hand bike may be a good idea - fortunatley a recent purchase was OK.

[Pickled Onion]

Coke ( Coca Cola full fat) has been known to work ( acid attacks the alloy bonded to the frame).

If that works, then plusgas and reasonable force would have worked. If the post is properly stuck then all that will happen is you make everything sticky. It makes a good story, but the acid in coke is (pretty obviously!) not very strong.

If you've got somewhere you can safely leave the frame for a week with caustic solution in it, then I can vouch that it does work and won't damage the frame.

[Oxford_Guy]

Think I'll try Plusgas and Loctite Freeze and Release (both over a period of time), if neither of them work, then I'll probably just send the bike of to the Seat Post Man. Thanks for all the suggestions!

[ElyDave]

Coke ( Coca Cola full fat) has been known to work ( acid attacks the alloy bonded to the frame).

If that works, then plusgas and reasonable force would have worked. If the post is properly stuck then all that will happen is you make everything sticky. It makes a good story, but the acid in coke is (pretty obviously!) not very strong.

If you've got somewhere you can safely leave the frame for a week with caustic solution in it, then I can vouch that it does work and won't damage the frame.

It's phosphoric, which is quite a strong acid, but quite dilute.  I'd avoid conc phosphoric though as that's rust remover which will also do the same to paint.

[tonycollinet]

I had my seatpost wedged in the grate of a cast iron road drain while rotating the frame. All I managed to do was rotationally bend the seatpost. I took it to LBS and they charged me £20 to remove.

[Feanor]

Where's that thread about dissolving the seatpost out?
Found it.

There was another thread, called something like 'how I cooked my bike', with pictures of a frame clamped in a workstand over a cooker, with the seatpost in boiling Caustic Soda.

I can't find it now.

The only one like that I can remember was using alum to remove a broken steel bolt from an alloy frame . . .

more accurately i've used this method to remove a broken tap (hardened steel), which i used to remove a broken bolt..

but this is not suitable for a stuck alloy seat post!!

Yes, I think that may be what I'm remembering.
My memory of the thread is vague.