I recall seeing something similar on inexpensive Italian bikes, circa 1975. Those head tubes were not investment cast, though. But the idea and construction technique, were the same.
Fred Rednor - Arlington, Virginia (USA)
> From: donald gillies <gillies@ece.ubc.ca>
\r?\n> Subject: [CR]Trek and the IC Head-Tube?
\r?\n> To: classicrendezvous@bikelist.org
\r?\n> Date: Thursday, October 16, 2008, 12:15 PM
\r?\n> Re: (This is borderline on-topic, my apologies if it
\r?\n> isn't) :
\r?\n>
\r?\n>
\r?\n> http://ebay.com/
\r?\n>
\r?\n> in particular:
\r?\n>
\r?\n>
\r?\n> http://img1.iwascoding.de/
\r?\n>
\r?\n> Is TREK the only company to make investment-cast (IC)
\r?\n> head-tubes? Can
\r?\n> someone comment on the quality (either the weight, or
\r?\n> durability) of
\r?\n> TREK IC head-tubes? Has anyone ever had a failure with one
\r?\n> of these?
\r?\n> How did TREK deal with the 'orange-peel' from the
\r?\n> sand casting process?
\r?\n>
\r?\n> This innovation was developed in about 1983 or 1984. It
\r?\n> saved a lot
\r?\n> of time and cost in the manufacture of the lower-end TREKs,
\r?\n> as no lugs
\r?\n> had to be brazed onto the head tubes, and they probably
\r?\n> didn't need to
\r?\n> mitre the top or downtubes on these bikes. Any idea how
\r?\n> many hours of
\r?\n> work it saved in assembling a frame? Thanx.
\r?\n>
\r?\n> - Don Gillies
\r?\n> San Diego, CA, USA