Ready for hitting the MTB (mountain bike) trails, this modular double chainset features a hollow carbon fibre crankarm construction with a forged aluminium spindle. This gives it a superior strength to weight ratio as you blast across the rock gardens, tree roots & debris at speed. FSA has also kitted out this model with a unidirectional finish & CNC-machined aluminium chainrings, so you can enjoy its powerful torque, speed & smooth operation, without adding any unnecessary weight to your ride. Megatooth Technology Very long, asymmetric teeth in a thick-thin alternation create a tremendously quiet & secure engagement. FSA's innovative Megatooth chainring has been developed to meet the needs of top-level riders. The design allows the chainring to retain the chainring completely by itself. Modular Thanks to this interchangeable system, any rider or mechanic can easily, quickly, & safely swap out the spider, spindles, & chainrings from one set to another. Lightness The hollow carbon fibre arms with UD finish saves weight & improves the stiffness of the chainset. Manufacturer's Part Number: 313-0312755030