If you plotted a three set Venn diagram with low cost, stiffness, and durability as your values, the X9 GXP 3.3 10-Speed Crankset would fall squarely in that sweet spot representing a perfect blend of all three factors. Truvativ uses a hollow forging process to make sure that the X9 cranks meet these performance/value criteria. Sure, their high end carbon fiber cranks are a few grams lighter, but their higher cost puts them off the mark in comparison to this offering.The hollow 7075 aluminum arms are ideal from a durability standpoint. You can stomp on the pedals as hard as you like and you know that not only will they resist deflection, but they'll be tough as nails. And if you ride in rough terrain, that's a nice thing to know when you tag the crank arm on a boulder. Fitted to the aluminum spider, are Truvativ's latest 22/33/44T chainrings which include a highly refined set of pins and ramps to provide smooth shifting under power. A standard 104/64mm four-arm bolt circle diameter and trick dual-sided 5mm/6mm alloy chainring bolts make for work when it's time for replacement or service.The X9 GXP 3.3 10-Speed Crankset uses the proven Truvativ GXP bottom bracket design. While the non-driveside sealed cartridge bearing is sandwiched between the left crankarm and a shoulder on the bottom bracket spindle, the other bearing is allowed to 'float' laterally, allowing for a zero preload arrangement that lasts longer and runs smoother.The Truvativ X9 GXP 3.3 10-Speed Crankset is Black with Grey, Red, or White accents and is available in two crankarm lengths -- 170, 175mm. It must be used with SRAM's GXP or GXP pressfit bottom brackets (GXP included).