Specification crank bcd 104gearing 32 34 36 38ttooth widenarrow tooth profile for better chain retentionchain 10sp shimanokmcsram 11sp sram xx1 chainmaterial 45mm plate 7075 t6 aluminum for superior stiffnessano hard black anodizing for longer wearrear derailleur must be used with mid or long cage clutch type rear derailleur example shimano shadow or sram type 2in very rough terrain or just for pure security we still recommend use of an upper guide technology stamped an