SHIMANO Dura-Ace CS-7800, Ultegra CS-6600, 10-Speed 11T Cog Review Posted by GiantPandaisy July 2, 2018 in Drivetrain Components This fits your . Make sure this fits by entering your model number. Cog Teeth: 11teethTeeth: 11 Teeth Dura-Ace/Ultegra 10 speed CS-7800/CS-6600 cogs. Cycling Outdoor Recreation Parts & Components SHIMANO Sports & Outdoors