What is this frame?
 

I picked this up on craigslist for a song. It is beat up really badly, but should be ride worthy. I know nothing about its history but it seemed sketchy. The cheap white rattle can paint is obviously not original. Judging from the fork the frame was most likely a yellow color. It has a vintage Shimano 600 headset that I'm guessing was original to the bike, but who knows. Shimano Dura-Ace 7402 crankset, 600 EX brakes and levers, 600 front and rear EX (RD 6207) derailleurs and downtube shifters, Campy hubs. The parts seemed all over the place so who knows if anything was original. It has Campy forkends/dropouts on the bent and destroyed forks as well as the frame (luckily only pelted with dents and not completely useless). I've photographed some of the seemingly more distinguishing characteristics to help, but I'm totally baffled. I thought the fork crown was sort of unique, but maybe not. The bottom bracket English threads, 68mm. 126mm rear dropouts. Guessing it is Japanese. Frame weighed about 4.6 lbs (with seat post binder bolt) and is 60cm center to center. Serial numbers under BB shell 14101 and 21588. Eager to hear what members have to say. Thanks for looking.

Fork crown is Haden and I think the lugs are Prugnat. I'd say it's from the late 70s. I haven't seen much of that crown on production frames so this could be a custom?

Interesting, thank you

I'm guessing not custom (although the previous poster could be right about the fork crown being more common in custom bikes). It doesn't have quite as much detail as was typical of custom bikes around this time was made. I want to say Japanese but the campy drop outs point in a different direction. Still I believe that a few Japanese high end bikes were made with campy drop outs. There are folks here with more expertise who will chime in. Nice bike; it will be fun to rebuild.

Thank you, I like it... seems like it will be worth the effort of getting it sorted. Hopefully someone does have the expertise to figure it out. It's a tough one to pin down.

could be a Batch produced UK or Japan frame .. nothing really unique .. put your name on it .

all the frame parts\ can be used by anyone , the seat stay pieces could be Cast caps , or they could be add-on flat sheet pieces .

I'm just going to piece it together as cheaply as possible with the existing parts and have some fun with it. I was wondering if any framebuilders would be interested in the damaged fork. I've got my dimensions for the new one and have no use for the bent old one. Wasn't sure if some of the parts would be reusable.

The seat stay style and brake bridge look just like my Centurion Ironman, same for the bottom bracket. Other than the campy dropouts, it looks like a Japanese frame to me.

I'm starting to lean towards Japan more and more. I just saw a Centurion Cinelli Equipe on ebay with Campy dropouts.

Any chance the bent fork could be cold set back to a usable state? It has a sizable dent on one of the blades but is not creased. I do not believe it bends where the steerer meets the crown.

don't use that fork. Use caution when putting it on the recycling pile for fear it might explode

Sounds like it's toast. I'm forked... time to buy a new one.:(

Stripped the frame and found stamp on down tube. Reynolds 531 Butted 20/23! That may help figure out the manufacturer.

No, that is not particularly useful information to lead us to the manufacturer. Reynolds used to mark their tubes to identify it was 531 tubing (they had other models) and the wall thickness. 20/23 describes the sheet gauge thickness that is roughly the equivalent of .9mm/.6mm. This was the most common tubing used by American builders in the late 70's. Actually all the parts of the frame look like pieces we could buy from American suppliers back then.

I've repainted hundreds of frames since the 70's and think this is most likely American made. What makes me unsure is the binder bolt. It looks like a binder was brazed onto a lug without binder ears. Japanese Nikko lugs didn't have ears like Prugnat lugs but these look like Prugnat lugs. They don't look like Nikko lugs at all.