Shimano's 105 Rear Derailleur for triples is a sweet upgrade. Shifting is almost effortless thanks to the light-action spring. Plus, the 105's top pulley stays a uniform distance from each sprocket so shifts resonates with the plunk of exact gear engagement. And the wide outer-pivot design increases rigidity for precision shifts every time.
Features and Information
Also available in Slate Black (image unavailable from manufacturer).