Hollow forged chainrings for Ultegra FC-R8000 crankset with 110 mm BCD and 4-arm spider. Hollowglide technology The chainrings are hollow to save weight and drastically improve stiffness and aerodynamics. They ensure optimum power transfer and improved shifting performance. In addition the bigger chainring (50, 52, 53 teeth) feature parts of carbon fiber reinforced polymers (CFRP). Note: These are chainrings from different types (MS, MT, MW). For optimal shifting performance only use chainrings from the same type. So it is recommended to combine MS with MS, MT with MT and MW with MW. Fitting for derailleur: 11-speed
