2 piece design double ring 9 speed chainset from the excellent value sora rangesg x chainrings feature strategically placed chain pick up pins and tooth profiles to ensure fast and positive shifting2 piece design allows the bottom bracket bearings to be spaced wider apart outboard the frame enabling the use of larger bearings and an increased axle diameterthere is also the benefit of easier installation adjustment and maintenancecompatible with hyperglide hg chainsaluminium crank armsalumini