Wolf Tooth Aero Direct Mount 1x Chainring - 50t 4-Bolt Drop-Stop ST Compatible Shimano Dura-Ace R9200/R9200-P Only BLKWolf Tooth Aero Direct Mount 1x Chainring 50t 4 Bolt Drop Stop ST Compatible with Shimano Dura Ace R9200 R9200 P Only Black. Designed for racing and for those looking to optimize each detail in pursuit of speed Wolf Tooth Aero Chainrings are strong lightweight and profiled to mate perfectly with your crankset for a clean integrated look. Taking advantage of 1x drivetrain systems and wider range rear cassettes Aero Chainrings for Shimano Dura Ace R9200