I am 5'10" when I stand really straight while thinking happy thoughts. My actual inseam using the Comp Cycle method is 33". I test rode a 2017 Domane S5 in size 56 and felt it a bit cramped. Note that my other two bikes (one I've had since 1990) are bigger frames. In any event, my LBS had a customer's Domane in the shop that was a 58---no test ride, so don't anyone go off. We checked it out noting the taller/longer head tube allows a bit more upright position. I ended up purchasing a 2017 Domane SL6 Disc in 58 that had gone on summer sale that AM at $1000 off (same price as the 2018s btw). I rode it a couple of weeks and then replaced the original stem (100mmx7 degree I think) with a 70mm x 7 degree. I've since changed the seat, and have a new Brooks B17 Imperial I'm going to install (probably tomorrow since the century I'd set out for cancelled for weather)...I'll be messing with the seat for a bit longer since I've also new pedals and shoes in queue. I have about 620 miles on the bike. It is a great bike.