I thought this might be useful if someone ends up in my situation, it took me a bit of digging but I got the idea here https://www.youtube.com/watch?v=wU9jbwVuSCQ
The dry ice was enough to remove the seatpost by shrinking it compared to the carbon, it was absolutely caked with corrosion. Lesson learned to always use carbon assembly paste. The bike stand was not enough to secure the seatpost, you need a bench vise and clamp it on the seat mount so it's secured for twisting.
by Barkinsons
3 Comments
i saw some mentally-ill people recommended toothpaste instead of carbon assembly paste…
The same happened to me, only in reverse: carbon seat post on steel frame. Found galvanic corrosion inside the seat tube and the only thing that worked was breaking the carbon seat tube into small pieces and use a long file to remove the corrosion. It took me several rides to be able to remove all the carbon shreds.
Use copper anti seize. I’m not sure carbon paste (the only one I’m aware of and used is friction paste on carbon on carbon and isn’t designed for metal to carbon) will do anything. It may buy you some time. Carbon and aluminum (or any metal) alloy will cause a reaction because of dissimilar metals. The copper in the paste will prevent the two materials from seizing. Aside from grease, copper anti seize is the most used “lubricant” I use on my bikes and cars. Tech changes so fast so check with the manufacturer as to what to use when rebuilding/reinstalling a part.
Kduos to a great solution though. This technique is commonly used in automotive when “pressing” together tight tolerance parts like frame bushings, etc. Works like a charm. Many times I’ve had bushings in my freezer overnight and they always slip right in the next day.
Although I don’t know what that extreme low temp does to carbon fiber. It may have become brittle? So watch that area.