The deore m617 10 speed 3622 mtb chainset from shimano is a great value 2 piece chainset for 10 speed dyna sys mtb hg x transmissions the 2 piece design features an external bottom bracket system which is a lightweight rigid design that is incredibly strong and durable the axle is made from a lightweight and rigid steel and the chainrings are steel with a lightweight aluminium outer ring the chainrings are sg x dyna sys plus chainrings with patented spike pins to give smooth and fast gear sh