I'm currently doing a build with 2013 SRAM drivetrain minus the crankset. The frame has an English BB shell and I installed a GXP BB. I have a 7900 groupset. I'm also going to building up a carbon bike(970 g) within a year. My plan is to move my SRAM drivetrain over to the carbon bike, hence my quandry. The carbon bike is a BB30 shell which wouldn't work if I bought the SRAM Red GXP crank. So, any thoughts how a 7900 crank would work with the 2013 SRAM yaw front derailleur?