Easton Direct Mount CINCH Chainring - 42t, 12-Speed, For Flattop Chains, Blackhe Easton direct mount CINCH chainring for Flattop chains has an updated tooth profile optimized for SRAM Flattop 12 speed chains. They use a narrow wide design specifically tailored to road cx gravel applications. The individual tooth profile has moved from the traditional symmetrical shape to more directional specific design with the intention to create a positive chain roller engagement to help with chain retention, critical to prevent chain slip