Park Tool's Crank Bolt Wrench - CCW-5C is designed for wrenching on older bikes with 3-piece cranksets. Square tapered as well as Shimano Octalink and ISIS Drive splined bottom bracket spindles require that either a 14mm socket or 8mm hex crank bolt be removed prior to pulling the crank arms. The CCW-5C has both the hex and socket and the long and comfortable vinyl-dipped handle offers plenty of leverage to loosen headstrong bolts.