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[Closed] CF Seatposts, Aluminium frames, cathodic corrosion.

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[#882527]

Can't move the cf seatpost in my aluminium cross frame- I suspect corrosion has occurred. Is there any way to confirm this is the case? Is there any way to remove the seatpost without too much damage? ๐Ÿ˜ฅ


 
Posted : 20/09/2009 3:39 pm
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How did you grease it? Have you applied anything else to the bonded area since?


 
Posted : 20/09/2009 3:40 pm
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Can't remember, but I suspect Shimano grease, probably about this time last year. Seatpost hasn't been taken out or moved at least all summer.


 
Posted : 20/09/2009 3:51 pm
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not supposed to grease CF post unless you use specific 'carbon friendly' assembly paste.
ie: http://www.jejamescycles.co.uk/tacx-carbon-assembly-item105138.html
(other makes and suppliers are available)

Mine stuck in (at the right height admittedly), so I spent a couple of week soaking it with GT80, and rode it with the seat clamp undone, it eventually came free without any damage.


 
Posted : 20/09/2009 4:26 pm
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I remember something about CF absorbing the components of normal grease, thus swelling and jamming. And not the good Bob Marley sort, nor the WI type.


 
Posted : 20/09/2009 4:29 pm
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coca cola down the seatpost (with bike upside down)? CC is a dilute phosphoric acid solution which should dissolve oxidation.

Lots of warm/hot water around the joint, in the hope the frame will expand more than the CF post?


 
Posted : 20/09/2009 6:06 pm