11-Speed Campagnolo Athena Chainring Campagnolo's Athena chainrings are 11-speed compatible. The outer rings have pick-up teeth to aid in shifting. Campagnolo chainrings have Campagnolo specific bolt center diameters. Chainring teeth 53-39 135mm BCD Chainring teeth 50-34 110mm BCD 5 Bolt 11-Speed Compatible