Fsa tt bb386 cranksetthis hollow carbon crankset is the newly re designed model for the tt family the hollow carbon arms and the al7075 cnc chainrings allow minimal weightcombined with maximum performance features hollow carbon arms with ud weave forged al7050 bb386evo spindle al7075 cnc chainrings al7075 torx t 30 alloy chainring bolts available for shimano 11 speed system weight 750gbuy fsa components from chain reaction cycles the worlds largest online bike store