Shimano Dura-Ace R9200 12 Spd Road Crankset The Dura-Ace R9200 12 Speed Chainset from Shimano provides the optimum balance of strength and rigidity at a low weight. Shimano's Hollowtech II and Hollowglide technologies provide outstanding power transfer and smooth gear shifts while it's engineered to excel specifically with the Shimano 12-Speed road groupset systems. The Dura-Ace FC-R9200 chainset is the driving force at the heart of the bicycle. This chainset ensures that no portion of your pedal stroke is wasted. With hollow arms and chainrings, weight is kept to a minimum but stiffness and shifting precision is maximized. Hollowtech II Technology for World-Class Strength at a Low Weight The Dura-Ace FC-R9200 crank performs two vital functions: transferring your pedalling effort into the drivetrain and ensuring the fastest, most precise front shifting available. With Hollowtech II crank arms to ensure lightweight and Shimano's class-leading chainring designs, the FC-R9200 won't let you down. And the FC-R9200 12 Speed Chainset is offered in even shorter crank arm lengths to ensure there are options to fit any rider. Hollowglide Chainring Technology Hollow technology on the outer chainring. The Hollowglide construction ensures high rigidity while its hollow structure cuts down on weight yet maintains strength. This provides better power transfer and quicker and more precise front shifting performance. Hollowtech II Forged Crank Arms A lightweight crankset not only reduces the bikes weight but decreases rotating mass to aid in acceleration. The challenge is to reduce the weight of the crank without reducing its strength and rigidity. Shimano's advanced forging technology has solved the problem through the HOLLOWTECH crank. Just like high-quality frame tubing, a hollow crank arm can provide amazing strength and rigidity at very lightweight. The Best Balance of Stiffness, Strength and Weight The concept of Hollowtech II technology is focused on producing a superior crankset that will maximize a riders power transfer. The rigidity of the crankset ensures pedalling efficiency while its low weight, a key element of the crankset, aids in cycling longer distances over which the rider needs to pedal more. Naturally, Shimano strove for the optimum balance between the conflicting needs of stiffness while producing a lightweight crank. The addition of Hollowtech II technology integrates the bottom bracket axle with the right crankarm for more stiffness and weight savings to achieve a high-dimensional balance. Its outboard bottom bracket bearing system provides better weight distribution and more pedalling stability, allowing for more efficient power transfer. The Shimano Dura-Ace R9200 12 Speed Chainset has been developed by pursuing the optimum balance of stiffness and rotating performance in a lightweight and beautiful crankset design.