Shimano's 105 Rear Derailleur is a sweet upgrade. With a body of light and durable cold-forged aluminum in Shimano's wide-pivot design with their light-action spring, the shifting is practically effortless and always super smooth. The top pulley stays a uniform distance from each cassette cog ensuring that every shift resonates with the plunk of exact gear engagement.
Maximum cog size: 30 teeth
Cassette compatibility: 10-speed cassettes