Greetings,
My guess is that it was built by one of the many somewhat anonymous US frame builders that sprung up and then disappeared during the mid to late 70s.
The seatstay caps or "eyes" are nicely done but the lug work is not very refined.
3977 could very well be March 9, 1977 ???
Looking at the components for hints of the frame's pedigree is a red herring as those kinds of bikes were usually custom assembled to the owners tastes and pocket book.
Chas. Colerich Oakland, CA USA
Dean Kernan wrote:
> All
>
> A pal has posted an unknown frame on another forum, and sadly none of us
> have been able to identify it.
>
> Two threads
> http://forums.roadbikereview.com/
> http://forums.roadbikereview.com/
>
> It is a mid to late seventies (seatstay clamp is fitted around the "new"
> Campagnolo bolt). Takes a 27.2 seatpost, English threaded BB, has all
> Campagnolo equipment including dropouts. Italian-esque long point lugs, flat
> fork crown (Cinelli?) Semi-wrapover seat stay attachment--looks almost like
> a Holdsworth...
>
> The distinguishing mark to my eye is the chain stay bridge. It is fairly
> small diameter and attached with diamond-shaped bosses that are cutout (so
> not like solid the deRosa diamonds he used on the chain stay bridge). For
> someone who knows (?)English frames this feature should be distinctive--you
> can see the bridge best in the pics in the first thread.
>
> Thanks,
> Dean Kernan
> Pomona, New York