The shimano fc 6700 ultegra 10 speed hollowtech ii chainset offers an ideal balance of light weight and stiffness making it the perfect choice for both road enthusiasts and competitive riders the chainset features hollowglide outer chainrings 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 conjuction with the cn 7900 and cn 6700 chains for increase