Hey guys!
Greetings from the new guy

I am in the final stages of building my own bike but a tad bit confused about the dimensions of the head tube for a 1 1/8" threadless headset.
I found a resource called Sheldon Brown's Bicycle Headset Dimension (sorry, the forum not allowing me to post URL before I complete 10 posts). Does it say that the internal diameter of head tube for the 1 1/8" threadless headset should be 30.0 mm?
Can someone please help me?
Thanks in advance
Best wishes,
Hughes