Originally Posted by
rydabent
The bottom line here is money. It is far cheaper to just filet weld bike tubes with robots rather than braze a frame with lugs. Just plain money grubbing greed.
I don't think many bike frames are robot TIG welded. There are some factories in Taiwan I've heard of doing that but I believe most are welded by hand. Lots of robot MIG for low end steel bikes and also aluminium.
There are plenty of ways to screw up the brazing of a lugged frame and I don't think anyone would argue it's really better from an engineering or reliability standpoint. It was done historically before TIG became widespread and because at the high end we only had non-weldable alloys like 531 (which may have been a bit of a chicken/egg type scenario). It's still used on custom bikes for aesthetic reasons.