To be the fastest, you want lightweight products, and at 133g the MXR BB is just that. This lightweight Euro bottom bracket has threaded CNC alloy cups, alloy spacers and 4 high quality sealed replaceable cartridge bearings.¢Euro Type 68mm BB shell (BSA)¢19mm axle compatible (axle not included)¢Variable, adjustable chain line.¢4 replaceable sealed bearings.¢Alloy CNC cups and spacer kit¢Weight:133g