2-piece design double-ring 9-speed chainset from the excellent value Sora range SG-X chainrings feature strategically placed chain pick-up pins & tooth profiles to ensure fast & positive shifting 2-piece design allows the bottom bracket bearings to be spaced wider apart &40;outboard the frame&41; enabling the use of larger bearings & an increased axle diameter There is also the benefit of easier installation adjustment & maintenance Compatible with Hyperglide &40;HG&41; chains Aluminium crank arms Aluminium outer chainring with hard-wearing steel inner chainring Compatible with 9-speed drivetrains 130 mm bolt circle diameter