Self-extracting crank caps on SRAM and RaceFace cranksets use a 16mm hex fitting that you can't reach with a standard hex key set. Park Tool's BBT-16 Self-Extracting Crank Cap Tool is the dedicated interface for those caps, shaped to engage the 16mm hex hole and drive the cap in or out without damaging the fitting. The butterfly-style body gives you enough grip for hand-driven installation and removal under normal conditions.

Where the BBT-16 earns its keep is the built-in 8mm hex fitting on the opposite end. When a cap is seized or overtightened, you can insert an 8mm Allen key through the tool body and use that lever arm to break the cap free. That matters because self-extracting caps sit in a threaded interface that sees preload torque, threadlocker residue, and corrosion over time. Without a way to multiply your leverage, a rounded or stuck cap turns into a much bigger problem.

The tool is investment cast steel, so it handles repeated use and the occasional drop without concern. If you're running any SRAM, RaceFace, or Truvativ crankset that uses the one-key release or self-extracting cap system with a 16mm hex hole, the BBT-16 is the correct tool for the job.