Innovation often comes from places you'd least expect. In order to make a lighter crankset, SRAM made it bigger. To add stiffness, SRAM used less material. The new SRAM Red 2012 Exogram Crankset is completely hollow all the way to the spider. Its hidden bolt pattern makes better use of carbon fiber to further improve stiffness & shed weight. The stunning X Glide R chainrings are optimized for use with the YAW Technology in the front derailleur, delivering seamless, flawless performance. Exogram: The new Hollow Carbon Construction starts in the crank arm & extends into the cranks' spider. It maximizes the stiffness to weight ratio. X-Glide R Chainrings: The chainrings are designed for an optimized shifting performance with the Yaw front derailleur. The stiffer rings (5mm 7075-T6 aluminium CNC-machined) feature upshift rivets with an advanced design adopted from SRAM XX. CNC machining allows for precision control of each tooth shape, ramp, & nearly every shifting feature of the chainring. Chainrings, chain, & front derailleur are designed as a single integrated system for optimized performance.