Like all components in the new Tiagra range the rear derailleurs have also seen some minor changes. The derailleur gets smoothed over a little bit and again add the longer lever of the more expensive groups with the cable bolt moved past the p-knuckle pivot. The alloy body and outer link leads to lower weight without compromising strength and durability and two fluorine-coated link pin bushings offer low-friction performance. The light shift action is complemented by large 11 tooth pulleys which reduce pulley wear and chain noise. Maximum Sprocket: 30T (Short) 34T (Long)NB: Not compatible with Shimano Tiagra 4600 drivetrains, only compatible with Tiagra 4700 shifters.