I know these come up now and again.

I’ve just brought a second hand Charge plug and the seat post is well and truly stuck. It seem as though the alloy post is a touch to big for the frame as on close inspection I can feel a bulge in the frame 🙁

I’ve tried the following:
– Removed the collar fully
– Twisting motion
– Upside down standing on the saddle (vice like) whilst 2nd person tries to twist frame
– GT85 soaking
– Ice / Boiling water
– Given it a telling off and a stern look
– General violence

What next, cut it out or hand it over to the lbs to have a crack at it?

To top it all I thought I’d replace a brake cable on my commuter and stabbed the old cable into my thumb, grrr…. 👿

The lbs will repeat exactly what you’ve done only they’ll charge £30 an hour.
http://www.sheldonbrown.com/stuck-seatposts.html

hmmm… looks like cutting it out, if only I had an extra 1-2″ longer legs it wouldn’t be a problem

Platform shoes?I’ve got a 456 with a very stuck thomson post to sort out at some point.

I have had best success by combining your point 3 with points 4 and 7.

Liberally apply penetrating oil, wait, apply more, repeat till bored, remove saddle, hold seat-post in vice (say goodbye to seat-post), apply brute force using frame as lever, twist and pull at same time. (Of course I hold no responsibility for you bending the frame either).

I’ve sucessfully used number 10 in sheldon’s list. Tried using various things to dissolve the oxide but all failed. It was a really long job though, I reckon about 6 hours split over 4 days to cut the seatpost twice lengthways. You will still need to prise the two surfaces away – I used a big screwdriver and a mallet.

If your stuck seatpost is one of the ones that is a tube with a the clamp assembly bonded on you could look to break the bond, pull off the clamp and cut the post down to the right length before putting the clamp back on. Secure it again by drilling a small hole through both post and clamp and using a bolt the same diameter as the hole you drilled to keep it tight – also use some loctite bearing fit to bond the two surfaces again.

I had thd eaxct same thing.

The bulge is butting in the seat tube AFAIK

Penetrating oil won’t work as it’s aluminium oxide and that won’t be disolved by that.

Ammonia solution will dissolve it.

Or get a big ass bench vice, bolted to a big heavy bench, remove saddle, clamp post head in vice and use the frame as a big lever.

Don’t heat it as Aluminium expands quicker than steel.

Last option is a small reciprocating saw and cut the bugger out.

SilentSparky, i have a lot of experience of seized seat stems and what i normally do is mark the stem at the bottom with a black marker, so if the stem moves at least you know. Cover the top of the stem with a strong piece of wood and using a really heaver hammer / mallet, wrack the stem downwards towards the bottom bracket and normally this will start to break the bond, secondly if you can rig up a 3ft / 4ft pipe connected to the top of the stem and whilst somebody is holding the frame try and lever / twist the pipe around, unscrewing the stem out of the frame.
Good look !!

I was told once that Coca Cola does the job of breaking down the oxidisation ………. not drunk the stuff since!!

Drill a hole crossways through the post (yes, bye-bye post), as near to the seatclamp area as possible (hole goes through thickest bit and through inserted bit of alloy in 2-piece seatposts). Stick something through it, such as massive screwdriver and the put long bar on the screwdriver. Hold on tight to the frame and start turning the seatpost, putting upward pressure as it turns.

Sorry to hijack the post but whats the best way of stopping a carbon post welding its self to an alu frame?

Thanks for all of the advice, just got to decide:

a, Sell the bike on, but actually mention this problem unlike the seller did with me, not a problem if you have a c.33″ leg as its not a bike where you’d move the post once its set.
b, Get the LBS to tackle it (I don’t have a vice)
c, Buy some retro platform shoes
d, Get busy with a hacksaw

Re: a, Charge Plug – Medium, so if your 5’11-6’2ft with a c.33″ drop me a line 😉

Had exactly the same problem on exactly the same bike.

Linky

hmmm…. acid do they sell it in Tesco’s 😀

Glad to know the frame is ok though, the bulge is in exactly the same place.

I fit that description. How much for the bike?!

Yeah it’s been fine ever since, just needs a lick of paint to tidy up.

Girlfriends Dad supplied the acid and came up with the suggestion, I’d pretty much exhausted all other options by the time I let him loose on it!

jimmyjames – £140