SRAM 2012 Red CranksetsExogram technology uses a large, hollow cross section all the way to the spider, minimizing weight while maximizing stiffnessStiffer X G lide R chainrings feature thicker construction, advanced shift timing pins and ramps, which are optimized for shifting with the Yaw front derailleurHidden bolt pattern leverages the characteristics of carbon fiber while presenting a sleek appearanceUse same bottom brackets as current SRAM road cranksNot compatible with older SRAM shifters and front derailleurs