Great value Deore 2-piece design chainset for 9-speed transmissionsThe 2-piece design chainset features an external bottom bracket system which is a lightweight rigid design that is incredibly strong and durableLightweight and rigid steel bottom bracket axleSG-X chainring with patented spike pins give smooth and fast gear shifts under loadLightweight aluminium outer with steel middle and inner chainringsWe recommend that the bottom bracket is initially installed by a bike shop to ensure perfect facing and fitMega9 compatible