Subject: Re: [CR]Walter Serena= Serena bikes (vs. old Schwinn)
dddd asked:
I was at first wondering if it was related to Schwinn's "butt-brazing" (isn't that what they called it?). Obviously not related! Anyway, does anyone know what that long-standing method entailed? I've always wondered, and believe it wasn't brazing at all but was really welding.
ddddwas right, some Schwinn models used "spot welding" or "resistance welding" in which two tubes were brought into contact with a very strong electric running through them which melted and welded the ends of the tubes together. This produced a ring of "flash" on the outside of the tube joint that had to be ground/sanded away.
Schwinn's method was fast, cheap, effective, and smart, but it did require the use of fairly thick tubing. Combined with Schwinn's production of seamed tubing from strip and stamped/formed/welded "lugs" used for the bottom bracket and head tube, Schwinn's method was extremely efficient and nearly vertical in operation (everything produced "in house").
Hugh Enox