Shimano's new Ultegra 6800 SM-BBR60 Bottom Bracket was made with the same high level of precision that you've come to expect from the engineers at Shimano. The silky-smooth steel bearings, advanced sealing, and high manufacturing tolerances make the SM-BBR60 the perfect bottom bracket choice for either your frame. The 6800 bottom bracket weighs in just around 76 grams, making it close to 15 grams lighter than its predecessor. In addition to the making the bottom bracket smaller and lighter, Shimano says that the design of the BBR60 reduces rotational friction by 50%. This is said to be due to advancements in Shimano's sealing technologies.