It's funny you posted this! I am 6'1", a bit big for a 56, so I am on a 58. But when my seat is set at just the right spot, I felt like I was reaching JUST a tad... So my local bike shop gave me a 100 to replace my 120 stem, and MAN what a difference... 10x more comfortable now. My bike shop just gave it to me for free, too.

6'1" + 58 bike + -20 stem = perfect for me. I would say my leg, to torso, to arm length is right about average all around.