Originally Posted by
delbiker1
The medium cage will work with a 36T just fine. If you think that is not enough additional low gearing, a 46/30 crankset could be the way to go.
You don't know this. OP still hasn't said exactly which GS derailleur he has. The 6800 will work w/ a 32, the 8000 a 34. I'd normally be comfortable w/ using a 36 w/ the newer 8000 derailleur, but not necessarily the 6800.