Bottom Brackets

The mystical inner working part of the bicycle that gets talked about in hushed tones and shouted at when you don’t have the right tools at hand. Bottom brackets (BB) thread or press into your bike’s bottom bracket shell and provide the bearings and support for your cranks. BB shells come in a variety of standards developed by key bike manufacturers like Shimano, SRAM, Trek and Specialised.

BBs form part of the ecosystem between your bike frame and its drivetrain, and it all has to be compatible. So choosing a BB is normally associated with ensuring it’s a) the right fit for the frame and b) the right fit for the cranks. For this reason, BBs are often bundled with cranks so that compatibility is ensured. For a longer read on bottom bracket terminology, check out this great article written by Park Tools.