Here's something cool: an Ultegra front derailleur that works as a top pull or a bottom pull. The addition of the Umlenker means that it can be used as a top pull, making it more useful for CX bikes with top cable routing for the front derailleur. I've tried it, it works well. The Umlenker is a German made product by a company called Speen. $30 takes it. 34.9mm clamp.