Derailleur: SRAM Red WiFLi Derailleur

High cadence is the key to climbing: The faster you can spin the gear, the faster you'll ascend while reducing muscle fatigue. The WiFLi – short for wider, faster, lighter – lets anyone amp up the rpms thanks to an 11-32 cassette that provides a greater (and smoother) selection of gears than almost any available triple chainring. Invest and your quads will thank you. [$380; sram.com]