The newly designed crank arms offer an optimized balance between lightweight and efficiency. The crank, formed with hollow aluminum technology, is anodized with a beautiful gloss black anodized finish, giving it a luxurious look. The resin ribs on the back of the chainrings are SHIMANO 105's unique structural design that achieves both thorough weight reduction and crisp shifting performance.

• Optimal balance of stiffness, strength, weight and rotational performance
• HOLLOWTECH II structure cuts weight yet maintains strength for better power transfer
• Crank arm length: 160, 165, 170, 172.5, 175 mm
• Gear combination: 50-34T, 52-36T
• Q-factor: 148 mm