Well. 45s do not fit. Let me rephrase. I got it in there, the wheel spins, but the lugs hit the chainstays. 700cx45, measured 42.5 with my calipers.
I picked this and a 700x40 at the Bike Collective yesterday. The 40 ought to fit. The 45 can be on the front I suppose. I also picked up 4 different lengths of stems for my other bikes... Fine tuning positions.