HomerSimpson Posted February 23, 2009 Share I would have been very disappointed in my own experience if Coke did work. Still' date=' it's still to have some ice cold Coke with you when taking on this job. If I can emphasise just one point it'll be PATIENCE. [/quote'] I personally believe cold beer works better. But you are right, the hacksaw is the only thing that works. Once you get the seatpost out you'll see how limited the penetration of all the chamicals was.... Link to comment Share on other sites More sharing options...
GoLefty!! Posted February 23, 2009 Share Johan's method is the only way to remove a seized seat post. Link to comment Share on other sites More sharing options...
Marius Posted February 23, 2009 Share My Carbon Seatpost is stuck in a Carbon Specialized frame, how do I get it out without twisting the Carbon saddle in two in the process? Link to comment Share on other sites More sharing options...
Flemish Lion Posted February 23, 2009 Share If the seatpost is alu - just drill a hole through it - put a metal bar through and twist it back and forth... at least u can re-use the alu seatpost and it's lighter too Link to comment Share on other sites More sharing options...
Johan Bornman Posted February 23, 2009 Share My Carbon Seatpost is stuck in a Carbon Specialized frame' date=' how do I get it out without twisting the Carbon saddle in two in the process?[/quote'] I have no idea by what mode the two carbon parts can fuse. The chemists here should be able to help...Hoooooomeeeeer, your phone is ringing. You have some history with this bike so maybe you can provide some clues. If there was grease on the post before it was inserted, you could have a case where the grease had dried out, leaving only the hard waxy soap behind. This has a relatively high resistance to shear (twist) in that application and prevent the two sliding over each other. I'd attempt to fit an old or scrap saddle with steel rails and see if force doesn't twist it out. Be patient and listen for creaks whist doint this. Vulnerable joints are where the seat stays connect to the seat post. If that doesn't work, then go for the method I described above. You'll have to be extra careful since filings from the frame and seat post are both black. Take photos, we'd love to see. Link to comment Share on other sites More sharing options...
Marius Posted February 23, 2009 Share thx Johan, don't remember doing anything special to the Seatpost, have actually not moved it since I bough the bike almost 4year ago, so maybe it's just some dirt that's gotten in, but I'll try the "put new saddle on methord, thx! Link to comment Share on other sites More sharing options...
HomerSimpson Posted February 23, 2009 Share My Carbon Seatpost is stuck in a Carbon Specialized frame' date=' how do I get it out without twisting the Carbon saddle in two in the process?[/quote'] I have no idea by what mode the two carbon parts can fuse. The chemists here should be able to help...Hoooooomeeeeer, your phone is ringing. I was too busy having lunch to answer phones. But you are right, can't think of a reason why the two epoxy/carbon parts should fuse (unless one of the two parts was incompletely cured/tacky, but that's highly unlikely. HomerSimpson2009-02-23 06:22:43 Link to comment Share on other sites More sharing options...
AndreZA Posted February 23, 2009 Share My Carbon Seatpost is stuck in a Carbon Specialized frame' date=' how do I get it out without twisting the Carbon saddle in two in the process?[/quote'] have you tried losening the seat post clamp/collar? Okay, I'll get my coat tomorrow. Link to comment Share on other sites More sharing options...
GoLefty!! Posted February 23, 2009 Share carbon fibre components incarbon fibre components don;t actually fuse. What occurs is swelling of the tube that makes up the seat post. SOmehow the tubes that make up the bike frame are not affected. the only causal effectI can attribute to this phenomenon at this time is that there is difference in Carbon fibre quality between frame and component and a potential gradient still exists which results in ion exchange at the joint intereface. Interetingly the swelling is localised to the contact area only. Link to comment Share on other sites More sharing options...
Johan Bornman Posted February 23, 2009 Share carbon fibre components incarbon fibre components don;t actually fuse. What occurs is swelling of the tube that makes up the seat post. SOmehow the tubes that make up the bike frame are not affected. the only causal effectI can attribute to this phenomenon at this time is that there is difference in Carbon fibre quality between frame and component and a potential gradient still exists which results in ion exchange at the joint intereface. Interetingly the swelling is localised to the contact area only. I've never seen this, most likely 'cause the only carbon in my posession I can think of is stuck t my braai grid. Actually I lie, there's also a bottle of carbon pills left over from my last bout of curry gut. Tim, are you saying that upon examination of the post (once removed), it will display a bulge where the seat post clamp was? Is it visible with the eye? Against a straight-edge? Link to comment Share on other sites More sharing options...
HomerSimpson Posted February 23, 2009 Share What occurs is swelling of the tube that makes up the seat post. SOmehow the tubes that make up the bike frame are not affected. the only causal effectI can attribute to this phenomenon at this time is that there is difference in Carbon fibre quality between frame and component and a potential gradient still exists which results in ion exchange at the joint intereface. Interetingly the swelling is localised to the contact area only. There can be no potential gradient or ion exchange (could conceivably happen with glass fibre but not carbon). The only possible reason for apparent "swelling" would be improperly cured repoxy resin, so that some exudation of resin (or garvitational flow over a long period) to the surface could cause some contact adhesion. Epoxide resins will swell only upon exposure to chlorinated aliphatic solvents (like chloroform or dichloromethane) which are unlikely to come into contact with the seat post/bike unless the owner is a complediot (commonly known as a complijit) who decided to clean his bike with these solvents... Link to comment Share on other sites More sharing options...
NotSoBigBen Posted February 23, 2009 Share Oi Homer do you mind drawing me a picture ....... Link to comment Share on other sites More sharing options...
Marius Posted February 23, 2009 Share WHAT did you call me Homer??!!? I know what you look like and I think I can take you!! - I think I use to use chloroform on her the first few times I wanted to ride her, but after a while she got use to it and now I don't have any hassels, just get on and ride her when I feel like it! Link to comment Share on other sites More sharing options...
The_Break Posted February 23, 2009 Share What effect could sweat have on the parts (with/without carbon paste)? My club captain's post did the same. He eventually used a mallet to gently give the seat a smack in order to try "shock" release the parts if you know what I mean. It worked! But I must admit, it was the last thing he had an option of trying. Link to comment Share on other sites More sharing options...
NotSoBigBen Posted February 23, 2009 Share WHAT did you call me Homer??!!? I know what you look like and I think I can take you!! - I think I use to use chloroform on her the first few times I wanted to ride her' date=' but after a while she got use to it and now I don't have any hassels, just get on and ride her when I feel like it![/quote'] Hey M I didn't say Homo I said Homer ....... Link to comment Share on other sites More sharing options...
GoLefty!! Posted February 24, 2009 Share carbon fibre components incarbon fibre components don;t actually fuse. What occurs is swelling of the tube that makes up the seat post. SOmehow the tubes that make up the bike frame are not affected. the only causal effectI can attribute to this phenomenon at this time is that there is difference in Carbon fibre quality between frame and component and a potential gradient still exists which results in ion exchange at the joint intereface. Interetingly the swelling is localised to the contact area only. I've never seen this' date=' most likely 'cause the only carbon in my posession I can think of is stuck t my braai grid. Actually I lie, there's also a bottle of carbon pills left over from my last bout of curry gut. Tim, are you saying that upon examination of the post (once removed), it will display a bulge where the seat post clamp was? Is it visible with the eye? Against a straight-edge? [/quote'] Yip, thats what I'm saying. There is an increase in diameter of the carbon post where it was inside the carbon seat tube. Can't find orthink of a reason for this. It is not gallingbecause there is no powder present. As for the impossibility of electrical potential existing between carbon fibre components it is worthwhile reminding the reader that there different types of carbon fibre.PAN or Poly AcryloNitrile and Those derived from Regenerated cellulose. These yiled carbon fibres with varying properties and a wide range of tensile, yield strengths and electrophysical properties. So there exists a potential for an electrical gradient. Seatposts are typically made from cheap low yield, low tensile strength fibres whilst frame are made fromhigher tensile, higher yield strength material. Carbon content also varies in these fibres. We must remember that carbon fibre is very very seldom 100% carbon. It is usually an Amine chain with other groups (depending on base material). Of Course an ISP makes all these problems go away. Link to comment Share on other sites More sharing options...
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