Originally Posted by
john m flores
Interesting down "tube".
The "Deltec" cable. Dahon claims great things about strength and pedaling efficiency based on testing (results advertised but details not yet made public.)
There was a manufacturer in the late 80s/early 90s that used cables for the downtube as well based on the idea that a typical downtube operates primarily in tension.
Bike frames with tension cable members: Dursley-Pedersen, 1890s.