Originally Posted by
Chombi1
Technically I guess the fork leg tubes going over extensions from the crown does work the same as frame lugs, but in a reverse way. Most people otherwise recognize lugged construction as lugs going over the frame and fork tubes.
Yes, internally lugged crowns were available from a number of manufacturers, including Cinelli, Davis, Vitus, and others. They do take a little more care in brazing since you can't directly visualize the degree of braze penetration into the joint. Often, brass rings were inserted into the blades prior to assembly, and these melted with heat and provided internal penetration. Here are a couple examples from Takahashi and Zeus:
