Shimano Dura Ace Di2 RD-7970 Rear Derailleur

Product Description

Programmed motion allows for quicker and smoother shifting with less chain drop. Servo motor keeps gear changes identical and precise every time, as the computer control unit analyzes each shift. Built-in saver (fuse) function moves the derailleur inward under impact, reducing the potential for damage in the event of a crash. Derailleur recalibrates and realigns itself with the cassette following an impact. Carbon pulley cage and P-body with titanium B axle lighten the load while maintaining strength, rigidity and performance.