The HollowTech II 10-speed Ultegra chainset offers an ideal balance of light weight and stiffness, making it the perfect choice for both enthusiast and competitive ridersHollowGlide hollow outer chainring gives vast improvements in rigidity by virtually removing outer chainring flex and hugely improves shift performance, even under high loadThe chainring teeth have been developed to work in conjunction with the CN7900 and CN6700 chains for increased contact to provide greater efficiency and improved power transferIndustry leading HollowTech II cold forged hollow crank arms have been evolved to increase rigidity, reduce weight and improve strengthA wide range of chainring options and crank arm lengths are available to meet the needs of all riders and racing disciplinesHollowTech II integrated bottom bracket uses a wider bearing placement and larger axle diameter for increased stiffness and efficiencyHollowTech II integrated bottom bracket seal design has minimal bearing interface ensuring smooth rolling and increased durabilityWeight including bottom bracket 788 grams