To make the BB86 a tough bottom bracket, we use the best materials. This means the shell is made from a combination of fibre and plastic. This allows us to machine it precisely and allows it to fit precisely in the frame and eliminate squeaks. It also provides a stable platform for the bearings and gives them a longer lifespan.In order to make this bottom bracket even more durable we use our patented X-Seals to keep moisture out while keeping drag to a minimum. The optional ceramic TBT bearings are extremely hard making the rolling resistance low and saving you precious energy. And since these bottom brackets are hand-assembled, we can be sure that only the most precisely made bottom brackets are ever packaged and sold. Sure, it’s a lot of effort but details matter.