Head tube length alone does not tell the whole story since it doesn't account for BB drop. Stack height is what gives a complete picture of your position on the bike, and they are wildly different from the previous one. 23mm taller stack height increase from the old bike is crazy. That's almost an inch taller! The 613 number doesn't look right since the carbon HT is only 15mm taller than the aluminum (which also doesn't seem right considering they look the same in pics), but Specialized assures that the published numbers are correct, which doesn't bode well.
2018 vs. 2017
Stack: 613 vs. 590 mm
