Shimano Dura-Ace Rear Derailleur
Shimano's Dura-Ace Rear Derailleur boasts a light and reliable cold-forged-aluminum body with a carbon cage and a wide pivot design that boosts rigidity for smooth, speedy shifts. Fluorine-coated pivots minimize friction for nearly effortless shifting. And, the oversize sealed-bearing pulleys are silky smooth, ultra quiet, and keep out dirt and water. Plus, the 7900 accepts up to a 28-tooth cassette cog for even greater gearing possibilities.
An important part of a rear derailleur's job is keeping the chain taut as you change gears. Chain-wrap capacity is a number that tells whether or not a derailleur will be able to do this on the drivetrain you plan to use it on. Calculate chain-wrap capacity with this formula: Chain-wrap capacity = (large chainring - small chainring) + (large rear cog - small rear cog). Example: 53/42 chainrings and a 12-23 cassette: (53 - 42 = 11) + (23 - 12 = 11) = 22-tooth chain-wrap capacity.
Largest cog this derailleur can handle: 28 tooth
The Dura-Ace Rear Derailleur is 10-speed compatible.
For optimum shifting and braking, Shimano 7900 Dura-Ace components are best as a system (they're not recommended for use with previous versions of Dura-Ace).
Weight: 166 grams