Stuck seatpost (I've tried everything)

Try Mercian: http://www.merciancycles.co.uk/renovation.asp

I sent an MX Leader with seized seat pin to Mercian a while back. I tried hanging the frame upside down, filling the ST with 'plus gas' (after the coca-cola trick didn't work!) and then putting pin in a vice. TBH was worried that the seat cluster was going to twist.

Cost for collection / return was £30 + £25 to remove the pin. They used an acid of some sort and thank the gods, the original paint work was untouched...... Hallelujah

After the amazing success that caustic soda did on my stuck stem I'd recommend blocking off the top of the seat tube/post and turning the frame upside down, then pouring caustic soda solution down the seat-tube somehow. In two days it will have dissolved.

After the amazing success that caustic soda did on my stuck stem I'd recommend blocking off the top of the seat tube/post and turning the frame upside down, then pouring caustic soda solution down the seat-tube somehow. In two days it will have dissolved.

What...Everything?

i had a 26.8 post stuck in a steel frame tried all sorts of ways to get it out heat slide hammer drills etc....

the best way to get it out it with a hack saw blade.

basically wrap one end of the blade in a cloth and keep the blade as level as you can and start sawing.it can be a bit long but i went to engineering shop and got a slightly longer wider blade so it wasnt so flimsy and sawed.

the idea is when you eventually saw threw the post it kinda collapses on its self.i stuck seat post is like a compressed spring...so wen the balde goes threw it weakens this and it kinda "pops" next thing you no you can slide the remainder of the post out

Had this problem on a 1950s Claud Butler. Coca cola didn't work, but a strong solution of caustic soda did the trick. This dissolves the alloy but it won't harm steel (although it will ruin the paint). Had to renew the caustic solution every day and within a week it had dissolved the entire seatpin. Obviously, you have to take great care with caustic and it will only work if you can seal the seat tube at one end or the other. It's a last resort really, but it works if you've got a steel frame. Wouldn't want to try it with an alloy frame though...

If you can get a bike shop to remove the seatpin for around a tenner, that's the best and easiest option.

bet you didnt try...putting your thumb in your mouth and blowing as hard as you can?

My brother managed it on a 50's Holdsworth using the hacksaw method. You just have to bide your time with it, take it nice and easy.

Having a vice/work stand would probably help.

yeah yeah yeah. cutting was an option although i did try and progress was slow. Also i dont have half the equipment and if im gonna spend £20 buying stands, new hacksaw blades etc would rather stump up for a professional to do it. Found this which was good: http://www.carlgerrard.org.uk/seatpost/ for anyone who does want to try cutting method.

really what i wanted to know when i started was who i can go to in london who'll do this for me (which vinyl villian kindly answered 3 days ago!)

Here is a picture of the Dave Russel, post heating - the paint removed by the process showed where the blade used in previous attempts had broken through the steel - 531 can be insanely thin in places - these cuts were not visible through the paintwork, and only became apparent after the heating - my point is be very careful if you do attempt to hack saw, as you might significantly weaken the frame without realising it - i m going to get the seatube replaced now, as it is a frame worth saving

waltham forest bike recycling centre have a great vice ( with teeth ) that will grip the seatpost you then turn the frame ( max leverage ) and hey presto seat post comes unstuck
i think they charge about a 3'er or a 5'er to rent tools and a workstand most saturday mornings
i tried everything to budge mine and could get it to move an inch.... the vice they have there has a special adaption which freed the seatpost in two shakes of a lambs tail

bet you didnt try...putting fizik bartape all over it and blowing as hard as you can?

fixed

update: went to mend-a-bike and they managed to get it out... for a tenner!took 4 days or so. Helpful sorts too...

brilliant stuff. Thanks all for the advice. Saved me about £40...!

Good stuff!

This forum could do with a FAQ section...

the forum is a FAQ, i'd advise using Sheldon's website or the Park Tool website for more concise advice.

laughs. My guvnor is sheldon browns auntie, so I doubt i'd need either tbh.

with steel frames, ignore sheldon's or anyone's advice on cutting.

I've said it so many times before, use caustic soda if the frame is steel and the post is alloy. you need the post for leverage with any other method, cutting it off will not help if it is welded to the inside of the frame! ally reacts with steel and that's what happens.

If the post is just tight, then lubricant and leverage will work, after all, someone got it in there in the first place.

As a side note, Mend a Bike are excellent. I work over Fulham way so when something goes wrong on the commute I always just drop in and they seem to fix on the spot. Just 2 days ago they fixed my BB that had cracked loose. Nice one fellas!

with steel frames, ignore sheldon's or anyone's advice on cutting.

I've said it so many times before, use caustic soda if the frame is steel and the post is alloy. you need the post for leverage with any other method, cutting it off will not help if it is welded to the inside of the frame! ally reacts with steel and that's what happens.

If the post is just tight, then lubricant and leverage will work, after all, someone got it in there in the first place.

I have had a stem stuck in a fork in caustic soda for about a week... I didn't help much, it was still stuck.... cutting it took less than 2 hours.

mend a bike sorted my stuck seat post the other day - cost £25 but i'd tried everything. They ended up sawing it out so i didn't even have to repaint the seat tube. Legends !

OK folks, I bought the best part of a bike (off organicorigin) and school boyed it and didnt ask/check if anything was stuck in, guess what? EVERYTHING is stuck in... couple of days, WD40 and a large hammer got the BB out so I am now on to the seatpost, alloy (i think) in cro mo, tried WD40 and previously mentioned large hammer with no luck so moving on to chemical based methods.. going to try coke first, then ammonia, and finally caustic soda, am I right in thinking caustic soda will render anything alloy unusable? cheers.

OK folks, I bought the best part of a bike (off organicorigin) and school boyed it and didnt ask/check if anything was stuck in, guess what? EVERYTHING is stuck in... couple of days, WD40 and a large hammer got the BB out so I am now on to the seatpost, alloy (i think) in cro mo, tried WD40 and previously mentioned large hammer with no luck so moving on to chemical based methods.. going to try coke first, then ammonia, and finally caustic soda, am I right in thinking caustic soda will render anything alloy unusable? cheers.

have a read through this: http://www.velonews.com/article/99640

i might use caustic soda as a last resort. if you're not precious about the seatpost, then i'd use a benchvise first, then a hacksaw if that doesn't work, and then move from there.

good luck.

Stuck seatpost (I've tried everything)
Then there isn't anything left for you to try.

Coca cola for a week?
http://www.londonfgss.com/thread1083-3.html

The seller should have disclosed the issues!