Light and strong these s works carbon mountain arms give you the competitive advantagegt best strength to weight ratio on the marketgt third generation hollow carbon crank arms offer superior stiffnessgt oversized alloy spindle with hirth coupling interfacegt 42mm bb30 cartridge bearingsgt fitsgt specialized frames with 845 osbbgt all frames with 73 bb30pf30gt s works chainrings and spiders available separately in triple and double configurationsgt availab