Arm Material: aluminum Arm Length: 175mm, 170mm Chainring Sizes: 30, 32t Bolt Circle Diameter: direct mount Rings: 32 Shimano has raised the bar with its 12-speed crankset, featuring an optimal gear combination and ratios designed for trail riding. Delivered in a powerful package with stylish details, the FC-M6130 crankset features a direct mount chainring with 30-32t chainring options to meet your needs. Offering superior chain retention for smoother riding over rough terrain, this crankset delivers the stiffness you're looking for on the trail. Dynamic chain engagement offers stronger chain retention and smoother pedaling for your afternoon ride while a 2-piece design ensures a balanced ratio that's stiff and lightweight with efficient power transfer. And, you'll be sure to turn heads on the singletrack thanks to the Deore logo color gradient that changes hues with light angles.