Chainring bolts rarely make the priority list until one goes missing or strips during a ring swap. Shimano's FC-M970 Inner Chainring Bolt Set provides the factory replacement hardware for an unusually broad range of cranksets spanning both mountain and road disciplines. The same M8 x 10.1mm bolt that secures the inner ring on XTR M970 and M980 cranks also fastens chainrings on Dura-Ace 9000/9100/9200 and Ultegra 6800/R8000/R8100 road cranksets. If you're maintaining multiple bikes across categories, one bolt set covers a lot of ground.

The set includes four aluminum bolts finished in black anodizing to match the factory aesthetic. Each bolt uses a Torx T30 head, which provides more positive engagement than hex interfaces and resists cam-out when you're applying proper torque. That matters because these bolts thread directly into receivers machined into the outer chainring on road cranks or through the spider on mountain cranks. Overtorque strips threads in expensive components, while undertorque lets bolts back out under load. Neither outcome improves your day.

Shimano applies a light green threadlocking compound from the factory, which holds bolts secure under normal riding conditions while still allowing disassembly with standard tools. If you're the type who swaps rings frequently for event-specific gearing or seasonal changes, a touch of standard grease works instead. Just check bolt tension periodically if you go that route. The official torque specification runs 12-16 Nm, though field experience suggests the lower end of that range reduces the risk of thread damage in aluminum chainring receivers.... Read More