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 riders HollowGlide hollow outer chainring gives vast improvements in rigidity by virtually removing outer chainring flex and hugely improves shift performance, even under high load The chainring teeth have been developed to work in conjunction with the CN-7900 and CN6700 chains for increasedcontact to provide greater efficiency and improved power transfer Industry leading HollowTech II cold forged hollow crank arms have been evolved to increase rigidity, reduce weight and improve strength A wide range of chainring options and crank armlengths are available to meet the needs of all riders and racing disciplines HollowTech II integrated bottom bracket uses a wider bearing placement and larger axle diameter for increased stiffness and efficiency HollowTech II integrated bottom bracket seal design has minimal bearing interface ensuring smooth rolling and increased durability Weight including bottom bracket 785 grams