So I was looking at other similar bikes geometry, and looked at the Trek Domane in size 56. Whats funny, is the frame reach on that bike is EXACTLY the same as the frame reach on the defy medium (54.5 size). 37.7. It also may explain why other mfg's sizing charts suggest 5'9" height being the cutoff for a 54, while Giant says medium goes all the way up to 5'11" height. The specialized however, run longer reach on both sizes for the robouix