COMPATIBILITY For Shimano 2×11 speed cranks with 110 mm Asymmetrical bolt circle diameter (4-arms): Dura-Ace R9100 Ultegra R8000 105 R7000 and Dura-Ace 9000 Ultegra 6800 105 5800 Tiagra 4700 Not compatible with Shimano 2×11 cranks with PowerMeters Chainrings you may use the following chains: all 11sp, 12sp Shimano 11sp, 12sp SRAM Flattop KMC chains Note: the chainring 1X is not compatible with the 2X setups INFORMATION ALUGEAR chainrings are some of the lightest chainrings on the market. Using our experience and vigorous testing, we tweaked the arm design and strategically machined the chainrings so that only minimal sacrifices were made in impact strength in exchange for large gains in weight reduction The chainrings are CNC machined from 7075 T6 aluminum and hard coat industrially anodized to provide protection from mechanical impacts, a good look, and an excellent tactile feel to each of the chainrings that lasts a long time A unique tooth profile eliminates chain noise, reduces wear, and provides smooth operation on the entire system of all the most common combinations, such as 10, 11, and 12-speed drives ALUGEAR chainrings are the best choice if you are looking for a technologically sound chainring with a unique design and low weight RECOMMENDATIONS For the best appearance, you may use ALUGEAR AERO COVER (for Ultegra R8000 cranks) Also, you may use ALUGEAR chainring bolts and nuts for mounting: 7mm nuts and 6,5mm bolts are required We recommend the use of a clutch system rear derailleur for the best chain security It is also a good idea to use a new chain with your new ALUGEAR chainring It is recommended to use a well-lubricated chain on every ride INSTALLATION INSTRUCTIONS The chainring installation scheme The chainring installation scheme with Cover The chainring installation scheme with Nuts and Bolts