XX1 Direct Mount:~ Developed for maximum chain control, each tooth's thickness is precisely CNC-machined to support the chain's inner and outer links perfectly. Come standard with 32T direct mount rings. Each X-SYNCª chain ring fits a single, universal spider - allowing you to change rings without removing the light-weight carbon crank arm. BB not included.
• New tooth profile alternates thickness by inner and outer links, providing maximum chain control
• Carbon arms with forged aluminum spider
• Weight: 650 grams with ring and BB(approx.) - BB not included.
• Must be used in conjunction with SRAM's XX1 complete group (rear derailleur, cassette, shifter, chain, cranks/chainrings)