You hit a rock, sucked a stick into your wheel, a bird flew into your derailleur, JRA we've heard it all when it comes to broken derailleur hangers. Whatever your reason is for needing a new 12x142 Pivot Derailleur Hanger, we've got you covered. Get out there and ride your little heart out. And for members of the cycling jet set that are prone to accidents, we recommend picking up an extra for your next trip. The 12x142 Pivot Derailleur Hanger works for Pivot Aluminum 5. 7, Carbon 5. 7, Mach 4, Firebird, Phoenix, Carbon 429, and Aluminum 429.