Campagnolo's Comp Triple Rear Derailleur is tailor made for triple-ring set ups for the ultimate in high-range gearing. Using Campy's standard advanced-parallelogram design, the Comp boasts the precise and quick shifting that they are well known for. Plus, the pulleys are even made from a special material that renders the drivetrain practically silent.
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: 44/29 chainrings and a 11-28 cassette: (44 - 29 = 15) + (28 - 11 = 17) = 32-tooth chain-wrap capacity.