Genuine Shimano Dura-Ace R9200 series. 40T Inner Chainring. Shimano Dura-Ace FC-R9200 54-40T Chainring Upgrade Kit – 12-Speed. 54T Outer Chainring. This is an upgrade over the standard 52-36T or 50-34T gearing, ideal for riders chasing higher speeds or racing performance.
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