The Shimano 105 rear derailleur is the new version of one of Shimano's most prestigious road rear derailleurs, now converted to 10-speed for a wider gear range. Without a doubt, it's a rear derailleur that's tough in all conditions, increases stiffness and is designed to maintain precision over long periods of use. The linkage design is wide to reduce shift deflection. It has a total capacity of up to 32 teeth.