The shimano fc 6800 ultegra 11 speed double chainset contains the latest in hollowtech ii features creating a super rigid light weight performance chainset perfect for anyone looking to improve their ride the outer chainring has been hollowed for increased rigidity leading to a highly improved shifting experience at any level of stress imaginable this road chainset boasts solid build features all the way through ranging from the improved best selling hollowtech ii cold forged 4 ar