Shimano Ultegra FD-R8150 12sp Front DerailleurCombining Shimano's new Di2 platform and the road incarnation of HYPERGLIDE+, the ULTEGRA R8150 front derailleur shifts between chainrings with our fastest, most seamless action. BENEFIT Our fastest ever front shifting, 45% faster than FD R9150 BENEFIT Smaller, sleeker, lighter FEATURE Frontal area reduced by 33% FEATURE Weight cut to 116 g BENEFIT Top gear teeth capacity: 46 52T