Rotor cranksets are available with two spindle configurations -- 24mm and 30mm. Given this, it only makes sense that they'd make a bottom bracket to fit both. Well they do, and this BSA 30 Road Bottom Bracket will allow the fitment of their 3D+ Crankset, with its 30mm alloy spindle, into frames with a standard 68mm English-threaded (BSA) bottom bracket shell.It uses the same 6906 steel bearings as a BB30 or Pressfit 30 bottom bracket system. However, this Rotor bottom bracket assembly carries the bearings in external cups rather than inside the frame like the aforementioned configurations. Rotor CNC machines the cups from 7075-T6 aluminum, and then they get polished and anodized Black. Since they're larger in diameter than a standard external bearing cup, Rotor includes a laser cut tool-steel wrench for installation. In addition to its handle, the wrench has a 3/8" square hole for your torque wrench, and the torque spec for the cups is etched right there on the wrench so you'll always know it.The Rotor BSA 30 Road Bottom Bracket is Black and will mate the Rotor 3D+ Crankset with any 68mm English-threaded bottom bracket shell. It uses high quality steel cartridge bearings.