Been thinking about this for a while and thought I would get the wisdom of the forum.....why did/do lugs (internal or external) persist so long on steel framed bicycles (not talking about new fangled aluminum here)? I have been around vintage motorcycles forever and one of the turning points for a manufacturer of mc frames is when they stopped using lugs (heavy cast bits) and started using "all-welded" construction, yet we continue to see lugged steel construction even today, on very lovely and high end frames.

I admit I love the looks of a lugged bike but I also love the workmanship in a beautifully crafted italian motorcycle without them (or I like to laugh at the bubblegum welds on spanish dirt bikes of the 60s)....so what is the reason behind the persistence of lugs?

On a related note, if you are going to use lugs then why braze the tubes - why not space age glue? Never have to worry about warping or heat treatment.....

Mark