The SD V2 External Euro bottom bracket runs its bearings outside the BB shell rather than inside it, in forged and CNC machined aluminium cups. SD build the bearings specifically for BMX use, and the external layout is there for greater durability.

It threads into a standard BSA/Euro shell, 1.37 inch x 24 TPI English, in 68mm or 73mm width. Any 24mm spindle crank suits it: SD Expert Lite, Pro and Pro Hollow, along with cranks such as Shimano, Rhythm and Bombshell. The whole unit weighs 128g.