The HollowTech II 11-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 11-speed HG-EV chains for increased contact to provide greater efficiency and improved power transferIndustry leading HollowTech II cold forged 4 arm hollow cranks have been evolved for maximum rigidity while reducing weightA 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 interfaceensuring smooth rolling and increased durability