The easiest way to have a front derailleur that can work with every frame is to buy a braze-on front derailleur, and then purchase a derailleur clamp when necessary. The Shimano SM-AD91 Front Derailleur clamp is that accessory.It is fabricated out of aluminum, hinged, and has a space for a braze-on derailleur fixing bolt to go through the clamp. It works not only with Shimano derailleurs, both mechanical and electronic, but also with non-Shimano front derailleurs.There are two sizes. 31.8 and 34.9mm. The 31.8mm size comes with a shim for 28.6mm diameter seat tubes.