Sram pressfit gxp ceramic bottom bracketceramic bb bearings exceed the needs of the most demanding riders they offer a performance advantage over traditional bottom bracket bearings thats almost too great to believe besides being 10 lighter than standard bearings ceramic bearings require an astonishing 78 less energy that the next most efficient bb on the market ceramic bearings are more resistant to dirt and moisture and when properly maintained will outlast and outperform any other bb o