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PostPosted: Fri May 24, 2013 10:31 pm 
Dirt Disciple

Joined: Sat Apr 27, 2013 6:50 pm
Posts: 99
The old chestnut of seat post stuck in frame. Alloy post stuck in an old Fire Mountain, whats the best way of retreiving. Frame is needed but seat post not. Also how to identify age of the frame, using the frame number or just down to the colour scheme? Thanks.

PostPosted: Fri May 24, 2013 10:48 pm 
Old School Hero

Joined: Thu Jul 05, 2012 6:35 pm
Posts: 209
Location: Hull
The best way if all else fails is a hacksaw blade inserted into the post and cut down the length of it very carefully,you might have to make two opposing cuts and it takes ages.You should know when your through by the feel and sound assuming its a steel frame.

PostPosted: Sat May 25, 2013 7:42 pm 
retrobike rider
retrobike rider
User avatar

Joined: Fri Mar 13, 2009 7:19 pm
Posts: 3299
Location: Leeds, for ages!
A process of elimination will make your life easier with a stuck post.

1. Get post in sturdy vice and nip up tight. Hold frame at either end for big leverage, rock (twist) back and forth gently, see how it goes. Could be loose now...

2. IF not, carry on with more pressure. still wont budge? I've heard of people bunging up exits at the post end and pouring anything from coke to plusgas fuel down the seat tube via bottom bracket shell and leave overnight to soften up the oxidised metal that's causing the problem, then repeat step one. May well work.

3. IF not. Try freezing it out as alu will move twice the rate of steel in either direction, which may shrink the post enough to release the bond.

see here for tips......

viewtopic.php?p=1706925 Brilliant example of mechanical intervention before destroying anything.

4. Still there? bloody thing! Now, can you see how the above has been low-cost and making chemicals work for you? that's the idea. So, from here you will have to decide whether or not the frame needs a repaint or to spend £20 on tungsten carbide hacksaw blades and days of stress and blasphemy. been there, done that, it has been done successfully but what an ordeal!
IF you have 60mm of post in there, fine. but you will probably have 150mm+. it's very hard to get pressure at lower point.
frustrating and time consuming with no guarantee of success.

Caustic soda. melt it out, hence "need a respray" as paintwork will be sacrificed.

see here for tips...

By stage 4 you can see how it gets messier and more expensive so, always worth trying the first options, first. It all simply reflects how badly seized in the post is.

good luck.

PostPosted: Sat May 25, 2013 8:33 pm 

Joined: Sat May 25, 2013 8:16 am
Posts: 4
Done #4 after getting through all the other phases this past week. Took some bloody time. Good thing is there was only some 4 inches inside the frame.

Main advice is DO NOT try to bulge it until you've at least sawed it to the frame on at least two sides.

I didn't and it costed me two more hours of work.

Patience and steady work. 20 mins here, 20 there. If you feel the urge to take it out but haven't reached the frame go and do something else. Really.

PostPosted: Sun May 26, 2013 8:24 pm 
Dirt Disciple

Joined: Sat Apr 27, 2013 6:50 pm
Posts: 99
Many thanks for the informative replies. I've tried the vice and i think the 2 piece post split rather than breaking the alloy steal seal but will try again tomorrow. If that fails then move onto the next step, thanks again.

PostPosted: Sun May 26, 2013 9:31 pm 
Gold Trader
Gold Trader
User avatar

Joined: Thu May 20, 2010 9:13 pm
Posts: 5614
Location: All you other Iron Men are just imitating
Steel frame with alloy post. Try ammonia before you down the caustic route. You can get it from wilkos etc for a couple of quid. It will eat away at the alloy oxide. Frame upside down squirt it in through the bottle bolt hole. A squirt of penetrating oil down there will ease it as the corrosion is attacked. May take a day or two but you paint work will be ok.

Oh.....and it stinks so best not done in the lounge :D

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