Shimano Ultegra 6800 HollowTech II Bottom Bracket

Shimano Ultegra 6800 HollowTech II Bottom Bracket The Shimano Ultegra 6800 bottom bracket offers a slightly updated shape and promises of up to half the friction over the previous 6700 bottom bracket. The Ultegra 6800 bottom bracket shaves approximately 14 grams over its predecessor; weighing in at just 77 grams.