An integral part of the Shimano Ultegra 12-speed road lineup, the FC-R8100 crankset builds upon Shimano's legendary front shifting and transmission efficiency. With new refinements for seamless 12-speed shifting, the Ultegra crank is now offered in a wide variety of lengths, bringing performance and improved fit for smaller riders, triathletes, and riders with specific biomechanic requirements. Optimal balance of stiffness, strength, weight and rotational performance. Hollowglide structure cuts weight yet maintains strength for better power transfer and quicker, more precise front shifting. 148mm Q-factor. 44.5mm chainline.