As Mountain Bikes continue to become more diverse, components must evolve. Deore XT addresses the needs of today"s riders just like it did when it was first introduced back in 1982 as the world"s first MTB group. Revolutionary new designs like the Shimano Shadow rear derailleur complement the the latest evolution of traditional designs to give you the right choice for your riding style. DEORE XT Hollowtech II Cranksets featuring smooth shifting SG-X chainrings, hollow forged crank arms, and integrated pipe billet axles.