Update: A front-derailleur clamp for braze-on front derailleurs, like the BBB ShiftFix, might be an even better option than the seat clamp. I especially like that an FD clamp hinges open; this eliminates the risk of marring the finish of the handlebars when sliding the clamp over the thicker part. Another big plus is the lack of an inner lip that has to be filed off. I’ll definitely try one on a future project and report back.
