World renowned Dura-Ace precision engineered cranks designed for the rigours of the oval circuit Hollow Tech hollow forged aluminium crank arms for light weight without compromising stiffness Splined Octalink fitting for Dura-Ace bottom bracket to create a strong & rigid interface Crank arms only chainrings available separately Weight: 505 grams (170 mm without chainring) Available in 165 170 & 172.5 mm crank arm lengths