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Discussion Starter · #1 ·
Any ideas how to solve this, short of sawing through post in strips (sounds dangerous on a carbon fibre frame). I heard that Aluminium oxide is the cause and that this can be disolved in ammonia - but what will this do to the carbon??

Any help would be much appreciated!
 

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Discussion Starter · #3 ·
It's an ITM Millenium black coated post - I've tried manually 'working' the post side to side using leverage around the seatpost clamp but it seems to be 'welded' to the seat tube!

Any ideas?
 

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If you have access to a sturdy bench vice you can turn the bike upside down and clamp the post so you can use the whole bike frame for leverage. A second set of hands makes this a lot easier. Cooling the post with an ice pack may help, the aluminum should contract more than the frame and give you a little extra clearance.

I am guessing the post is stuck because it was greased, this can cause the resin to soften and bond to the aluminum.

HTH
 

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Much wrongness

Furrner said:
I am guessing the post is stuck because it was greased, this can cause the resin to soften and bond to the aluminum.
Repeat after me: Complete and utter nonsense. If grease attacked carbon, then all those CF hub bodies, cranksets, BB tubes, and derailleur parts would be going to gunk and bonding to the adjacent aluminum. Doesn't happen, and didn't happen with this post either. If you have a respected source for this information, it would be instructive. Note: "bike shop mechanic" is NOT a respected source.
 

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I had a similar problem with a frame:

1. Turn bike upside down
2. b4 or after the 180 remove bottom bracket
3. pour some motor oil in seat tube( not believing viscosity matters, any grade)
4. twist and shout ( I let it sit a while)
FYI do not attempt over carpet... OOPS! sorry honey
 

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I am in the middle of a similar problem with a steel frame, with advice from this forum. I took a break for a vacation though so I have not solved my problem.

I just posed the question to a submarine mechanic here at work (one of the best I have ever met). He suggested an idea that I had not thought of. He suggested using a pneumatic nibbler hammer to vibrate the post and break the corrosion bond. Seems like a good idea to me, if you have the tool.

Read my thread to get some other ideas "The Worst Bike Problem I have ever encountered". Dry ice may work very well for you. The Coeff of Thermal expansion of carbon layup structures is very small. That means when cold the aluminum shrinks a lot, and the carbon only shrinks a little (if at all).

Ammonia did nothing for me, and it does not sound like a good idea for a carbon frame.

Be very wary of heat. THis could very easily damage the carbon. Plus it will make the aluminum expand a lot, but the carbon will not expand very much (if at all). So the grip will be tighter.

Good luck.
 

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I have used ammonia successfully with Ti and Steel frames. It will dissolve Al oxide if you leave it long enough, you have to give it enough time to work. Turn the frame upside down, remove bottom bracket, pour in the household ammonia and let it soak for a few hours. I'd contact the manufacturer, but I dont know why it would harm the resin on your frame. Certainly seems safer than ham-handed force, thermal expansion or attempting to cut-
 
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