Originally Posted by Sangetsu

One of the things I most like about the Birdy is it's ability to use standard components. I have an XTR 11 speed driveline on mine, with a Dura Ace crankset and front derailleur, for a total of 22 speeds. And it is all bolt-on, no fabrication or modification. And if and when Shimano comes up with a 12 speed system, it will likely bolt onto the Birdy as easy as the 8, 9, 10, and 11 speed parts do.