Someday, you may wax poetically as you regale your children with tales of mechanical rear derailleurs malfunctioning at just the wrong time. You'll shake your head as you explain how you'd have to throw your whole arm into the lever, hoping to get to the gear you needed in time to cross the finish line in the lead. But that nostalgia's for the future. For now, you're about to have a damn fine time celebrating progress. Set up your SRAM Red drivetrain then get out and go experience the most perfect shifts of your life with the Red eTap Rear Derailleur. Wireless AIREA technology sets eTap apart from earlier generations of electronic drivetrains, and its skill is as apparent in the rear derailleur's instant, crisp shifts as it is in your frame's clean, uncluttered appearance. Full carbon fiber cages don't add an ounce more than is necessary to your frame, while ceramic pulley bearings come with the pedigree to withstand years of lead outs, thrilling sprints, and impossible climbs without the slightest bit of hesitation.