Another thing that has worked for me in the past:
Assuming that you can get to the other end of the bolt (i.e. it's not a blind hole), you can drill into the end. The drag of the drill on the bolt after it's gone in a bit will often undo it.
But I'd give the bolt a good soak with plusgas beforehand to try and loosen it up. Protect the carbon post as best you can.
Assuming that you can get to the other end of the bolt (i.e. it's not a blind hole), you can drill into the end. The drag of the drill on the bolt after it's gone in a bit will often undo it.
But I'd give the bolt a good soak with plusgas beforehand to try and loosen it up. Protect the carbon post as best you can.