SLX Hollowtech II Cranksets feature hollow forged crank arms, durable pipe billet steel axles, and smooth shifting SG-X chainrings.

• Model FC-M660 features traditional MTB triple chainrings.
• Composite middle chainring double's its service life.
• Improved shifting and smoother pedaling.
• 2 tone coloured crank arm.
• High rigidity crank arms.
• Accurate chainline.
• 2-piece structure design.
• Reinforced construction for extreme riding styles.
• Increased ground clearance.
• Sizes: 170mm, 175mm crank arm length.