The only way to take maximum advantage of Double-Tap shifting is to employ the SRAM Red 22 Rear Derailleur. This is the lightest eleven-speed rear derailleur on the market, and it works like a dream thanks to the engineering smarts of SRAM. This is the same design derailleur launched with Red 22, though the graphics have been updated. The weight is a scant 145g for the short cage, 165g for the mid cage. The medium handles cogs as small as 11-teeth and as large as 28-teeth. The long cage ranges from 11-teeth up to 32-teeth. Several things stand out. First is the 1:1 actuation ratio, meaning that the distance the cable travels matches the distance the derailleur moves. Not all shifting systems do this. The benefits are easy setup, as long as the upper pulley is directly underneath one cog, it will be underneath all the cogs, and it’s easy for the derailleur to stay in adjustment. As you can imagine with such a light derailleur, liberal amounts of carbon-fiber are used. The inner and outer pulley plates along with the inner cage plate are all molded out of the wonder material. Titanium, the slightly older wonder material, is the stuff used for the hardware an pinch bolt. The pulleys are new and are called AeroGlide. These 11-tooth wheels employ a new tooth design to improve both sound damping and energy efficiency. The pulleys are finishes with ceramic bearings for virtually zero frictional drag. The Red 22 Rear Derailleur is designed to work with all SRAM 11-Speed shifting systems, including Red and Force Double-Tap, and SRAM’s bar-end shifters. The SRAM Red 22 Rear Derailleur lightens the load and increases confidence.