The new TR12 rear derailleur is able to provide a quiet and accurate ride over the roughest trails. The key feature to this pursuit is the Hall Lock. During the Race season, lead mechanic for Intense Factory Racing, John Hall, noticed excessive movement around the B-knuckle when riding over rough rock gardens and in tracked out corners. This was leading to more chain skipping and slapping creating possible variances in shifting. This inspired John's idea to lock the B-knuckle to the bike's derailleur hanger. TRP engineers worked closely with Hall to create this feature, The Hall Lock. - Hall Lock - G-Spec Ratchet Clutch - G-Spec finishing touches - Carbon fiber cage & upper link - Extra-wide parallelogram pivot - Sealed cartridge bearing pulleys