The Ron Cooper looks close, but I don't think Ron ever had headbadges, so the two holes in the head tube don't match.

Oh, yeah, those head badge holes. You'd think that would be a strong clue, along with two, rather than three, top tube cable guides. I suppose I should start scanning the British Lightweights site.

Shame about the cable guide on the Ron Cooper gouging the paint as it slides up.

this is nothing but a hunch, and based on nothing, too, but in spite of the initial similarity to a London-made frame (Holdsworth Super Mistral) there's something about it that seems more "Yorkie" to me...and by that broad term I'd include Harrogate, Leeds, Huddersfield...all them and more.

Yeah, I think your getting close with this thought. I said 70's but now I think it could be early 80's as well. What is the width for a rear hub?

Apparently Raleigh and Carlton used that sloping fork crown earlier. Have a look at this.

Rear is 120mm, so definitely 70s. I'm fairly convinced 1973, given that's the first two digits of the serial #.

Really the same, or just similar? All the similar treatments I've seen, by Eisentraut, Cooper, Trek, etc, were only similar. I haven't seen the same treatment anywhere.

Does the pinch bolt thread into the ear on the left side, or is it a two piece bolt? It looks like the former to me, which strikes me as an anachronism. Other than that, I agree with your 1973 date.

Oh, I suppose it's a similar treatment, not identical, but given that I'm mostly comparing to photos of various quality, it's hard to say for sure. As far as that pinch bolt, it's conventional: one piece, threads in from the drive side.

One thought came to me today. The dropouts on the front fork, are they Campagnolo or not? Could the fork not be original, is basically where I am going with this. Also a shot of the bottom of the bottom bracket lug would be nice.

Okay, that thought lead me to look at Eisentraut more closely. Look at this album for a 1973 Eisentraut, everything is pretty much there except holes for a head badge. The fork doesn't seem quite right either. but I know that people like Eisentraut and his students (Gordon notably) used Campy dropouts back in the day and all did that style of fastback stays. The flair on the lugs is right in this track bike from the same year and that fork looks close to what you have. So I'm going more in that direction now that I see that lug and yours.

https://www.flickr.com/photos/cortez...57626406158540

by cortezcycles, on Flickr

1975 Eisentraut here:

Office Bikes | LandUseOregon.com

Not saying it is an Eisentraut but I think that is the lug. However how the rear seat stays on both of those are slightly different than what you have as well as that fork crown. That 1975 had a 6 digit serial code too. Maybe an email to someone like Mark Nobilette or Bill Stevenson may help.

This is a fun game.

It has some very, very minor damage! But nothing too detectable.

Fork has Campy dropouts, so it's likely original (though 40 years later, who knows?). Here's a pic of the underside of the BB. Pretty nondescript:



And for the sake of comparison, here's a pic of the back of the seat stay treatment, followed by a pic of the seat stay on my '84 Gran Course:

I don't think it's "finessed" enough to be anything by one of the California Custom builders who did variations on this style fastback seat cluster. Eisentraut's signature style (which MAY have been the original that launched stylistic departures by his students and imitators) was certainly much more detailed and craftsmanlike than the simple fillet-brazed tubes on the OP's frame.
The full-sloping forkcrown on the example shown is a different brand, too, plus all his lug edges are thinned and smoothed...like the artist he was/is.
Nothing bad or wrong about the OP's frame, but I think it's more plain-vanilla, 1970s, and British-made.

I agree. In looking at those Eisentraut frames, I see a seat stay treatment that's fairly different, particularly with those scalloped ends.

I agree, those are the same lugs; but they are a widely available model as was already mentioned when [MENTION=17926]unworthy1[/MENTION] first chimed in. I'm pretty sure we'll know what this frame is when we find another bike with the same stay attachment, which was done by hand by the builder.

Here's a pic of a quite similar Hurlow fastback cluster:



I'm finding some interesting similarities with Hurlow/Condor frames that I'm seeing online.

Yeah, if you search for early 70's Condor Italia, you get a frame with the same lugs and same seat cluster as yours. Forks vary, and I haven't seen the two brake cable guides. Condor head badge appears to be a good match, though.

I'm voting for Condor Italia.

This repainted one was on ebay lately; fork and brazeons don't match, but...

The Condor's all get close:




The green one has the wrong fork crown, but the red one above lacks the right head tube lugs.


I wouldn't be surprised if it were something else from the same time period, though.

The wrong fork on the green one doesn't bother me much since both frames have obviously been repainted. Either one, or both, could be a replacement. The same goes for the various brazed on stuff on both frames; could be original, or not. Doesn't mean much.

What I'd like to know now is where were Condor serial numbers?

[MENTION=184818]dyander[/MENTION] has SN 7245 built in 1972 in this thread: https://www.bikeforums.net/classic-vi...ure-heavy.html

I love these kinds of threads. I have a Falcon frame that I would like to find out what model it is. I also have a bike with no decals or serial number that I would like to know the make/builder.

Thanks for the info on Condor. Certainly seems like lots of key similarities. I also managed to go on an extended test ride today in the very wet roads of the Boston area. Really could have used a fendered bike as I was soaked by the time I got home, but ah well. Here's a pic at the end of the ride. That's the snow pile at the top of the driveway:



Build is with SunTour Cyclone mechs with black bodies, Stronglight 49D crankset, Mavic rims with Campy low-flange hubs (5-speed rear), Challenge Eroica tires (30mm fit this frame just fine), Weinmann Carrera brakes, SunTour barcons, Shimano brake levers (not a C&V match, but probably my favorite brake levers), Brooks Swift, Nitto stem, some kind of rando bars. Yes, and that's a CF seat post; I don't see it at all when I'm riding!