last christmas, i built my wife a nashbar bike using dura ace 7800 groupset i got from my buddy.
it's 53/39 front and 12/25t back.
my wife doesn't race and finds that very difficult to ride even when we hit some hills.
the front will be swapped to a 7900 compact crank, so i think and hope the 7800 FD won't have issues with it.
as for the rear, since the 7800 RD is short cage, i see per manual, the smallest to largest it will support is 11/27t.
i googled and found ultegra 7900 has them in 11/27t.
so would my 7800 RD have issues if i'm running an ultegra 7900 11/27t in the rear?
any compatibility issues?