Hollowtech II cranksets use a dual-bolt clamping system to secure the non-drive side crank arm to the spindle, and this Shimano Crank Arm Clamp Bolt is the OEM replacement for that application. The M6 x 21mm bolt includes an integrated washer for proper load distribution across the crank arm's clamping interface. Shimano designed this fastener for use in pairs, with two opposing bolts creating the clamping force that holds your left crank arm in position.

Installation matters here. The correct technique involves gradually tightening both bolts against each other in alternating passes before setting final torque. Torquing one bolt completely and then addressing the second creates uneven clamping pressure and risks the arm working loose under pedaling loads. A dab of grease on the threads keeps things running smoothly and makes future removal easier.

This particular bolt specification fits a wide range of Shimano cranksets across road, mountain, and e-bike platforms. Road applications include the 105 FC-R7000 and similar Ultegra-level cranks. Mountain compatibility extends through the SLX and XT families with dual-bolt clamping designs, including the FC-M7000 series. E-bike cranks like the FC-E8000 and FC-E8050 from Shimano's STEPS system also use this same bolt. Because Shimano uses different fasteners across their lineup, verify your specific crankset before ordering. Shimano's exploded view technical drawings confirm which bolt specification applies to your particular model.... Read More