You guys are not wrong, but I purposely did not include the top cap and any shims under the cap to keep the focus on head tube length. The choice of top cap, where most of the variability in headset stack height occurs, is something I didn't want to complicate the discussion with. Since the bearings "disappear" into the integrated headset and don't change it's stack height, I normalized the non-integrated system with the same parts ending at the pressed in top race and bottom cup with bearings on top and inside the bottom. After that it is just a matter of choice.

Chaad, your reference to the 1" threaded steerer and headset is valid, but not for someone looking to buy a new bike today. I didn't mention the 12 cm head tube on the Romic to hearken back to our previous discussion about what bikes may or should have in the way of head tube length, but just to give an example that I had handy of how the head tube length changes when you add in the pressed in parts and bearings to a non-integrated head tube. Since the Romic was in the garage, I was able to easily measure it with and without those parts. I'm not trying to compare the finished height to any other bike. I just wanted to establish a base line for comparing head tubes on both kinds of bikes for someone in the market today.

So on the Giant, the head tube was a fixed 15.0 cm with the bearings hidden inside. On the Romic the head tube with bearings is about 13.5 cm. I can make those look more the same by choosing different top caps, but that is not my point. And Chaad is right that in a threaded headset setup the tall top cap with incorporated nut and also lock nut there would be more height making the two systems quite comparable. As it is, I'm using at threadless fork right now on the Romic, so things are different.

Please keep in mind this is neither a discussion of good and bad in head tubes, nor one about all the factors that contribute to final bicycle stack height. It is only meant as a reminder to folks to be aware when reading published head tube heights that the final bike stack height will depend quite significantly (AT LEAST 1.5 cm or so) on whether the threadless headset is integrated or not. Other factors in the bike design and other headset choices will also play a part, but the basic difference of 1.5 cm between the integrated and non-integrated designs should not be ignored. That's all.

On second thought I suppose I could have said all this more simply: for two head tubes with the same length the bearings in an integrated headset head tube will be about 1.5 cm closer together than with a non-integrated headset. That is really all I am trying to convey.