Shimano dura ace 9000 11 speed rear mechthe 11 speed dura ace rear derailleur has been redesigned for lighter operation with the help of new low friction polymer coated cables shifting effort is now more even across the range with similar force required at both ends of the cassette features redesigned rear system with new spring mechanism redesigned lighter shorter and more equal shifting operation carbon pulley plate wide link design to reduce shifting deflection and increases rigidity givi