Stuck seat post

[gazza19]

Hi everyone hope somebody can help me I’ve got a carrera mirage and the seat post is stuck any idea how to loosen it any advice would be greatly appreciated

 

[biggs682]

Been there had the tee shirt .
I would suggest trying to get some freeing off or release spray through bottle cage bosses if there any on seat tube , i read somewhere that somebody used a big length of 4 inch square timber with a hole cut out as per the clamp on top of the post and with some gentle persuasion a stuck post came out .
I have tried similar ways but till today i have never had one free up and have either sawn them out or machined them out using a drill both are messy and long winded .
If it's a 27.2mm dia post i have a special drill bit you could try

 

[gazza19]

Been there had the tee shirt .
I would suggest trying to get some freeing off or release spray through bottle cage bosses if there any on seat tube , i read somewhere that somebody used a big length of 4 inch square timber with a hole cut out as per the clamp on top of the post and with some gentle persuasion a stuck post came out .
I have tried similar ways but till today i have never had one free up and have either sawn them out or machined them out using a drill both are messy and long winded .
If it's a 27.2mm dia post i have a special drill bit you could try

not sure of the size i got it like that but didnt realise the post was stuck until i tried to move it as the seat was to oneside and not in the middle

 

[Gillstay]

And spray into the chainstay tubes where you can, then leave it upside down to soak. Use good stuff not WD40. Warm the tubes up as well so the penetrating oil can work its way in. If we get another hot spell leave it in the sun.

 

[Cycleops]

That looks like a aluminium post in a steel frame. Quite common for them to fuse over time. The demise of many a good frame.
There are all sorts of methods from Coca-Cola to acid.
Have a look on YouTube 'RJ the bike guy' has about half a dozen videos which might give some guidance.

View: https://youtu.be/aXuc9dTH9qE


Also quite a clever one using a car scissors jack I hadn't seen before:

View: https://youtu.be/51tcpMS-j1E


The best of luck.

 

[iluvmybike]

Don't even go there . Contact John The Seatpost Man - https://theseatpostman.com/
He will remove it without any damage to your bike but dont make his job more difficult by attempting some of the things above...

 

[Arrowfoot]

If it is aluminium, penetrating oil does not work with aluminium oxide build. Ammonia or drainer cleaner is a better option. Place the bike up side down, pour the liquid thru bottle cage bosses and keep it like that for a day Do slight tapping every 6 hrs on the sides to allow more penetration. Hope it works.

 

[Cycleops]

Don't even go there . Contact John The Seatpost Man - https://theseatpostman.com/
He will remove it without any damage to your bike but dont make his job more difficult by attempting some of the things above...

I'm sure he does a grand job but on a budget bike the cost might exceed the frame's worth. Doesn't do any harm to get a quote I guess

 

[presta]

Also quite a clever one using a car scissors jack I hadn't seen before:

View: https://youtu.be/51tcpMS-j1E

I've used a car jack for removing fence posts like that a few times. On a bike, I'd be looking for the jack to be located more securely than that to prevent slippage before I tried it, and possibly the symmetry of a pair of jacks to prevent jamming or bending if it was tight.

 

[Cycleops]

...I'd also be worried about stressing the top tube. Those jacks can exert an awful lot of pressure.

 

[rogerzilla]

I'm sure he does a grand job but on a budget bike the cost might exceed the frame's worth. Doesn't do any harm to get a quote I guess

It will be more than the whole bike is worth: over £100 including shipping.

Try more twisting leverage first, applying it to the saddle. As soon as there is ANY motion, penetrating oil will get in there and free it. If that fails, the only chemical method that really works on an alu post in a steel frame is caustic soda. It will absolutely work, and you can save the paint if you're careful, but it is dangerous and needs the right approach.

 

[vickster]

See if an LBS can help?

 

[boydj]

Bike upside down with the seat in a vice, or jammed somehow, and twist, using the frame for leverage.

 

[Cycleops]

Bike upside down with the seat in a vice, or jammed somehow, and twist, using the frame for leverage.

That's fine if it's not badly stuck. If it is you run the risk of bending the frame as the amount of force you can exert is considerable.

 

[Ajax Bay]

Yup, spraying stuff on doesn't work. You can try the caustic soda bomb (I'm still wincing and feel little itchy splotches on my face and hands) or all the stuff you can read about on the internet ranging from Coke to organic lime juice, nothing works. Keep this recipe for when you decide to take the plunge:

1) Get a new seatpost now. Look out for an attractive bargain, buy it and store it.
2) Saw the existing post off 25mm above the frame collar.
3) Remove the hacksaw blade from the saw frame and wrap a cloth around one end. Keep beer on hand and swallow some patience. This is not quick.
4) Have a nice small torch handy.
5) Saw vertically through the remainder of the post stuck inside the frame. The idea is to saw a slot right through the post wall along the length of the post. You will score the frame but be patient, look frequently and adjust your aim as needed.
6) Once you are right through (you'll notice a different colour come through as you nick the frame, take a sip of beer.
7) Now take a pair of standard pliers or one of those hinged pliers (not longnose, you will destroy it) and grip the seat post stubby right next to the slot and wind the post up inwards. By that I mean you open it like an old fashioned sardine can.
8) As soon as the tube bends inwards, pressure is immediately relieved and it will come out in one piece. This seems surprising to most people but remember, it is stuck not through adhesion but through swelling. There is no bond between post and frame.
9) Clean as described above and fit your new post using copper compound or similar.
10) Promise yourself you will remove and check it every six months.

@Yellow Saddle 's recipe.