**Warning: Not compatible with pre 2015 Groupsets**Chorus 11-speed's shifting precision is comparable to its Record and Super Record siblings.The design and geometry of the rear derailleur are exactly the same. The only difference lies in the materials used, which made it possible to keep a favourable price without lowering performance levels.A groupset dedicated to competition, as the Chorus 11x is, shows off its carbon fibre front plate. The new shape of the external components allows the rear derailleur to move efficiently to give maximum performance at any angle. A new internal design keeps the chain closer to the cassette to ensure better power transmission, and a more positive drive, whilst allowing the component to move along a trajectory that perfectly follows the curve of the sprockets, on both the 11-23 cassette and the new 11-29. A better chain/sprocket interface also gives greater durability of components.CARBON FIBRE CAGE PLATE: Shifting positioning is exceedingly precise - extremely light.CARBON FIBRE PARALLELOGRAM, AND EXCLUSIVE ULTRA-SHIFT" GEOMETRY: Maximum shifting rigidity, fast actuation, precision, friction reduction.ALUMINUM FIXING BOLT: The new two-part system is 53% lighter than steel and 22% lighter than titanium, without compromising resistance and rigidity levels and prolonging component life.**Technical Specifications:*** Carbon fibre forged aluminium upper and lower body* Metal-carbon cage* Ultra light 2 part hanger bolt* Parallelogram with 11x geometry* Lightened special rubber pulleys* Weight 183g