Shimano's 105 Rear Derailleur 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.
Largest cog this derailleur can handle: 27 tooth
The Shimano 105 Rear Derailleur is compatible with 9- and 10-speed cassettes.
Weight: 228 grams