Among Shimano's multiple groups of road bike components, Dura Ace represents the company's premium offering. The Dura Ace 10-speed rear shifter uses a cable connected to a mechanism known as a bicycle derailleur in order to actuate gear changes. The derailleur is located at the end of the cable opposite the shifter. When shifter cables stretch too much, they no longer offer the tension needed to pivot the derailleur to certain gears. A new cable, adjusted properly, allows the shifter, cable, and derailleur to work effectively.