Bob Sutterfield wrote:
I forgot to mention: The boom tube is oval. I wonder if that's unusual, a narrow overlap in time with the Marathon lateral. Lots of bikes with Marathon laterals had twin boom tubes of regular-profile tubing, and ovaled tubing came later.
I'm preparing a photo gallery of its interesting details. Meanwhile
it's in action at
http://picasaweb.google.com/
<snip> +++++++++++++++++++++++++++++++ Bob - It's not terribly important, but I've rarely seen on-topic tandems with twin boom tubes. In my experience, by far the more common was a single oversized tube, which I assumed was either plain-gauge 4130, or salvaged from a kid's swing set. :-). Oval boom tubes were available in the "proprietary" Taylor 531 tandem set, and Phil (Wood) made an ovalized tube for a number of years, too. The dual tubes would have been very labor-intensive.
Indeed, Santana gave up the laterals when they realized that a single large diagonal avoided something like 9 fillet-brazed joints that required finishing, and resulted in a stronger frame. I don't remember the details, but it was stimulated by buying the tubing stock of another tandem maker who had gone out of business, if I recall correctly.
What do you call a tandem with twin laterals? "al dente"
harvey sachs
mcLean va.