Quoted message said:Barra of France was building welded, oversized tubed aluminuim bikes
back in 1936,
tandems and single bikes, vertical drop outs. I handled a '36 Barra
frame recently
looks a lot like a Cannondale, oversized down tube, ovalized at the BB.
The biken had an aluminuim fork with a double plate crown, very cool.
Bikes are great, people are regularly reinventing the wheel.
Scott G.
Scott G.
thanks for pointing that out! of course, it's /possible/ to weld
aluminum with a gas torch, which is what had to be done back then, but
the problem is that welds are of much poorer quality due to much higher
inclusion counts, gas porosity, etc and consequently have highly
inferior fatigue properties. the alloys for the tube weren't great
welding candidates back then either. not to mention the fact that the
holder of the torch had to be amazingly skilled - aluminum is a great
conductor, so keeping the heat local enough to weld without having huge
chunks of molten metal fall from around the intended weld area takes
almost super-human powers!
that said, if you can post pics of the barra, that would be awesome.