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Removing a stuck seat post or handlebar stem

Someone recently asked me what to do about an aluminum seat post or quill stem stuck in a steel frame.

First of all, let me explain how this happens.

When two dissimilar metals are placed together, in this case steel and aluminum, and moisture is introduced, ordinary rainwater, a form of electrochemical corrosion takes place known as “Galvanic corrosion.”

The two metals form what is known as an electrical couple, and electrons are exchanged between the two, through the electrolyte, which in this case is the moisture.

The first thing to try to release the two is heat. You could use a butane torch, but a safer and more readily available substitute would be boiling water.

Take the bike outside and lay it on the ground. Leave the saddle or the handlebars in place as you will need these as leverage to start twisting the component to free it.

Pour a pan of boiling water over the aluminum part. If you own an electric kettle this might be a better choice, because you can run an extension cord outside and boil the water right next to where you need it.

Because aluminum expands on heating at a greater rate than steel the seat post or stem is now even tighter than before. However, allow it to cool back to normal temperature, and the aluminum component will shrink. This expanding and contracting again is usually enough to break the seal, and free it.

In the case of a stuck seat post, grasp the saddle and start twisting back and forth. When it starts to move, use a little thin oil or WD40 to avoid tearing up the aluminum.

To remove a stuck handlebar stem, loosen the expander bolt, and tap down the expander wedge to release it, (You must do this.) and then remove the bolt completely before you pour the boiling water over.

As with the seat post, allow to cool completely, hold the front wheel between your knees and start to twist the handlebars. If the stem fails to move try this next step.

Remove the front brake, and try to get the expander wedge to drop out through the bottom hole in the steering column.

You must remove the expander wedge completely. If it won’t drop out, you may need to use a file or a Dremel tool to make the hole at the bottom bigger.

Sometimes you can screw the expander bolt back in again from the bottom and pull the expander wedge out. (Picture right.)

Now you can insert a piece of ½ inch diameter steel bar up inside the stem from the bottom side, and drive the stem out with a hammer.

Put some duct tape inside the fork blades to avoid chipping the paint with the hammer.

Ammonia, a common household cleaner, will also loosen aluminum corrosion, so you may also try soaking the part overnight with ammonia before you try to remove it. Ammonia is also corrosive to aluminum, so this is only a short term temporary measure.

The boiling water trick will also work to remove the crank arms from a bottom bracket spindle, if the extractor threads are stripped.

Only in this case, after pouring the boiling water over don’t wait for it to cool; you need the aluminum crank or chainwheel to expand away from the steel spindle. Drive the crank off while still hot, using a piece of wood and a hammer.

Because prevention is always better than a cure, make sure when you fit your stem or seat post, you apply grease to the inside of the steel frame, and to the aluminum component.

The grease will seal out the moisture, and stop the steel and aluminum from contacting each other. Remove your stem and seat post at least once a year and re-grease. More often if you ride in the rain a lot.

Reader Comments (33)

Useful advice thanks.

January 28, 2010 | Unregistered Commenterstephen_mc

I've been unsuccessful using various methods to remove the stuck aluminum stem from the steel fork/steerer of my vintage Schwinn. Never tried boiling water or ammonia, though. Thanks! I'm going to give this a try.

January 28, 2010 | Unregistered CommenterTamia Nelson

Nice tip Dave, thanks

January 30, 2010 | Unregistered Commenterjeny

Interesting - never tried using boiling water.

I've freed stuck seat posts with lots of WD-40 and/or oil injected through the seat tube via the BB and around the seat post clamp area. Then remove seat, use giant adjustable wrench clamped on seat post and/or clamp into vise - using entire bike as leverage to twist free. Scary though.

Your hot water trick sounds a lot a safer....

January 31, 2010 | Unregistered CommenterDan O

Useful information is always appreciable., should work this for me. Have to check how I can follow your instructions ... will tell you how it done

February 1, 2010 | Unregistered CommenterJamesArthus

Caustic is good for Al oxides

The other chemistry suggested is Oxalic acid solution if the problem is corrosion of steel

February 1, 2010 | Unregistered CommenterSweet William

Thanks for the tip Dave! I've used a tie-rod separator to remove a crank arm with stripped threads. (Heating the arms with boiling water would speed things up though!

February 1, 2010 | Unregistered CommenterTony

Thanks for the post. Very insightful.

February 3, 2010 | Unregistered Commenterkfir

Dave, I'm surprised you have to outline this article at all. Do peole not know about basic maintenance these days? I know I'm getting old but when I rode regularly (only as far back as the 70s, 80s and 90s) this information was passed on by parents and club mates but then, in those days we obeyed the rules of the road too. I guess I'm just becoming a grumpy old man!

February 6, 2010 | Unregistered CommenterGeoff Wood

Dave, the heat thing worked for me. Thanks for posting this tip.

March 24, 2010 | Unregistered CommenterJogi

Thank you for sharing the information with us. I have met the same situation due to the corrosion. Your post will help me much in the future.

December 20, 2010 | Unregistered Commentercorrosion control

As mentioned above, pour ammonia in via the bottom bracket, or far more simply, thru the waterbottle bosses whilst the bike is upside down (and outdoors). Leave for 48 hours. If possible, strap a vibrating object (ask your wife:) to the seat tube to agitate the ammonia to help it penetrate the gap between seatpost and frame. Remember rain water got in there to fuse it in the first place.
You'll need to seal up any holes in the top of the seatpost first. wear gloves.

August 9, 2011 | Unregistered CommenterJake

Much appreciated thread. To Geoff Wood- I learned lots from my Dad, but he grew up never having had a bicycle, so yes, GOL-ness may be upon you!! ;-)
I tried everything but the ammonia. What worked for me is 3-4 days of WD40 and Archimedes ("Give me a lever long enough and a fulcrum on which to place it, and I shall move the world."). A 6 foot wooden pole and a bench vise with wood and cushioning to protect the bike finish (also provided the opportunity to re-lube the bench vise to position it optimally).

August 13, 2012 | Unregistered CommenterLarry Ward

I,v used the boiling water trick on a few of my bikes to remove stuck front stems with great success (Carltons for some strange reason seem to be plagued with this fault lack of grease at the time of build both of mine are late 1980/81 versions disgruntled Raleigh employees before the strike killed Carlton off perhaps) Vinegar also does the trick but dont leave it in for more than 24 hours! If all else fails "and it does" resort to the hacksaw/hot spanner (oxy) I had to do this to a 1959 GB Stem on a Carlton Clubman 531 rather than damage the frame & forks when removed they were welded as if they had been a single item no boiling water alive would have shifted them apart regards Carlton Flier

August 30, 2012 | Unregistered CommenterCarlton Flier

After many other attempts, this worked. Thanks for the post.

September 5, 2012 | Unregistered CommenterMorgue

Regarding the ammonia approach, I've had a hell of a time figuring out a way to KEEP ammonia in the seat tube where the corrosion is and let it actually soak.

Do you have any advice for how to seal the narrow gap between the inside surface of the seat tube and the outside of the seat post? There isn't enough corrosion to create a closed seal there. Anything I can use to reliably but temporarily seal that crack?

I tried a rubber plug at the bottom of the seat tube (inserted via the bottom bracket shell) but that leaked too (though possibly I could try a smaller plug and get it farther into the tube.)


September 8, 2012 | Unregistered CommenterSam

Update on my predicament from the last post:
I finally tried wax to seal the crack between the seat post and the seat tube. I lit a candle, let the hot wax liquify and pool, and poured it around the crack until I had it well covered. I also did the same with the area around and below where the seat-post-binder bolt would go.

Also, after trying to just pour ammonia directly into the bottom bracket shell and losing too much of it that spilled out, I wised up with a funnel and plastic tube to get it in there.

It finally worked! Soaked it for about 2 and a half days. This morning I first hammered the seat post straight down until it moved , then hammered it in a rotating direction (mine has a non-symmetrical part where the seat mounts, like these, so I had something to hit for torque), and finally pulled it out by hand once it had loosened enough.

Success! A little of the excess ammonia spilled into the down tube and the chain stays in the process, but it's all out now and since the frame is steel, I shouldn't worry about any damage from that, should I?

September 20, 2012 | Unregistered CommenterSam

Hi I recently had the trouble of a stuck stem in my forks, I tried to just loosen it with wd40 with no effect at all, In the end I chopped off the handlebars just below the weld so I could just remove the forks and work with them on there own, I then clamped the forks in a workbench upside down, I then heated the forks where the quill/stem was left in the forks, after about 5 mins of heating evenly I got a solid steel rod the size of the stem and beat it with a Jameson it popped out of the too, heating the forks is key to this method as it expands the metal enough for it to loosen the remaining stem left in the forks, I think this method is best as I tried alot of other ways with no hope, thanks for reading and I hope this helps you, good luck

November 6, 2012 | Unregistered CommenterMatt oakes

I would be cautious about twisting handlebar stems too hard on the bike as it is easy to twist the fork or damage the welds where the legs join the cross piece because the leverage is both very high at that point and twists as the fork legs flex several mm.
Unless it is a particularly rare stem saw off and drill out is safest.
PS I have noticed that GT style frames are particularly difficult to remove corroded seatposts from because the complete and strong surrounding of the seat tube by the crossbar causes a slight "egg timer" half way down.

November 15, 2012 | Unregistered CommenterPaul

When all else fails pour Caustic Soda into your seat tube and keep emptying/refilling until your alloy seat pin is dissolved.


You may need to seal the seat tube at the bottom bracket (I used Blu-Tac)

You will need gloves and goggles because Caustic Soda is very dangerous

* Well it works on Alloy frames as well but you won't have much frame left.

January 17, 2013 | Unregistered CommenterFred Dered

Tony that boiling water trick did the job thx, the stem was seized big time, i have never thought of this before, very clad for the advice.

June 28, 2013 | Unregistered CommenterTony

Thanks for your suggestions. I tried the boiling water, and although it did not solve the problem on its own I am sure it helped. After two or three cycles of boiling water and at least a week of repeated PB Blaster I finially unstuck the aluminum stem from the steel fork of my friend's 1976 Schinn Superior. The pivotal step was to submege the stem in ice water twice for about a half hour at a time. Of course repeated twisting and hamering with a metal rod was required to finish the job.

July 27, 2013 | Unregistered CommenterRichK

I tried the boiling water on a Schwinn Beach Point with frozen stem. Worked like a charm. Thank you so much for this post. It would have been cheaper to buy another bike rather than take it to a shop. This cost nothing. Great tip!!!

September 11, 2013 | Unregistered CommenterCindy

After failing with penetrating oil, I tried the boiling water trick on my aluminium seatpost, stuck in a steel frame. No joy after four or five attempts. Subsequently I found someone with a table-mounted vice, and I was able to get it out following Sheldon Brown's #5 tip by moving the frame with the top of the seatpost in the vice. Very happy not to have to resort to the destructive methods :).

April 30, 2014 | Unregistered CommenterRicardo

This worked with a combo of a constant tiny stream of hot water on the steel, (electric kettle allows that control) and gel ice pack on the stem. Then it was a matter of twisting the stem with two Irwin quick clamps holding the fork to a work bench, and one quick clamp holding the other clamps in! When it broke loose, it sounded like it was breaking. It was so tight it made a crack noise when it would go back and forth. WD and massive force while twisting back and forth and she was out.

May 6, 2014 | Unregistered CommenterEricoftheNorth

Thanks a million! The hot water on the aluminum tube worked like a charm! Thanks again!

October 23, 2014 | Unregistered CommenterTaylor

I have tried it all and a hot tip from Adam at Lunar Cycles/London. I have cut the wobbly adjustable stem off and pulled out the fork. Will bo soaking the stuck remenent in a jar of caustic soda solution till de solved and then replace with a solid stem. Adjustable stems always wear out quickly. Wish me luck!!

February 3, 2016 | Unregistered Commenterthierry

It worked a dream! After 4 fresh mixes of caustic soda ( using a total of 500 grams) there was a couple of mm that just wouldn't dissolve ,but I was able to prize it away with a small screw driver.

Many Thanks to Adam at Lunar Cycles/ London for for the HOT tip.

March 8, 2016 | Unregistered CommenterThierry


So I have never seen this anywhere, but today (well over the last few days) I have had an incredibly stuck stainless steel seat post in a stainless steel frame of a winter beater bike i just purchase for snow commuting. Nothing worked WD40, Apple cider vinegar (may have helped a bit in the end), clamps, pliers...nothing.

So I thought what if i get a large metal drill and drill through both sides of the seat post (near the top) and insert a tempered steel bar inside the holes to create leverage (warning: make sure you drill a pilot hole in each side first before using the large drill bit).

Once you get through insert the tempered metal bar at get a hammer flip the bike upside down on a nice steady elevated surface. Now whack the bar alternating either side of the bar and you will definitely be able to knock it out. Your choice if you want to use the "holy" seat post (I did and its working fine as its a beater).

Can't recommend this enough and I can't believe no one else has done this!! Not sure how it would work for Carbon Fibre, but would work for Aluminium I expect and beats the hell of out caustic soda, which is incredibly dangerous for you and the environment

October 16, 2016 | Unregistered CommenterDavid M

I am in the process of bringing a Carlton Franco Italia of about 1965 (l think) back to life and was having a problem removing the handlebar stem. Your instructions worked like a dream, very pleased. Many thanks Mr Moulton .

January 2, 2017 | Unregistered Commenterchris nunn

I had a VERY stuck stem. Cut it off, removed the fork, heated the steering tube (which was exciting when the penetrating oil caught fire) then put the whole mess in the freezer. The hot / cold loosened things enough for extraction. My better half did question the burn marks on a bag of frozen peas....

February 7, 2017 | Unregistered CommenterClyde Putman

I had a VERY stuck stem. Cut it off, removed the fork, heated the steering tube (which was exciting when the penetrating oil caught fire) then put the whole mess in the freezer. The hot / cold loosened things enough for extraction. My better half did question the burn marks on a bag of frozen peas....

February 7, 2017 | Unregistered CommenterClyde Putman


Here's an issue that hasn't been addressed. The bike came this way so it's not me who failed to grease the seat post.

I too have a stuck seat post but,

1) It's an aluminum frame - with an aluminum seat post and so I can't use the Ammonia or other chemical tricks

2) It's an ALAN (screw and glue) aluminum frame, so it's not strong enough to use the "put seat post in vise and spin frame method".

Before I cut off a perfectly good Campagnolo seat post and then very carefully hand saw out the remains (which must then be replaced for about $200) I am seeking a shortcut.

My plan

I would wrap the seat tube lug with cloth, then turn the frame upside down and insert the exposed seat tube in a can and add liquid nitrogen to the can until the exposed seat post tip is covered almost to the lug. After two minutes the post should be seriously frozen. I'd remove the can of liquid nitrogen and and then lay the frame on it's side and pour boiling water on the seat tube below the seat tube lug.

If it fails I still have the cut -it-out option....

My question for Dave is:

Can you see any downside to this attempt? Could the temperature extreme between the boiling water and the liquid nitrogen weaken or even destroy the screw and glue?


September 17, 2017 | Unregistered CommenterWGB

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