evo.com | Shimano Chainrings > You can't see the Shimano SM-CRM81 XT M8000 1x Chainring while you're riding (hopefully), but you know how cool it looks. Shimano just nailed it with the aesthetics this go-around, on top of the excellent wear and chain retention we've come to expect. Bolt Circle Diameter 96 mm Dynamic Chain Engagement A special tooth shape that results in 150% better chain retention. 12 Speed Shimano Drivetrains 4-Bolt Connection | Shimano SM-CRM81 XT M8000 1x 96 BCD Chainring 2022 - 34T