Thanks again for the info juvela ,
I am still new to the vintage bike game. I had picked up a couple of odd frames and parts on my travels for cheap (2 frame sets [Cosme? and Chiementin?] and 1 bike [Olmo complete but unassembled; Galli stuff-any good?] @ about 50 euros each, some loose parts [various Campagnolo and more], and a Gaburro Professional frame set [now built] for 150 euros; all with minor dings, a little rust, and a repaint) before moving back to the States, and before I shortly retire so I will have plenty of time learn, and to work on them and figure out what they are.
I cannot find a 27.0 mm post (I don't have many parts), but I took a 26.8 (size stamped on it) post off of the Olmo and it fit quite loose in the seat tube. I will have to remove my 27.2mm (also marked) post from my rider to double check because I just kind of eyeballed the inside tube diameter (with a mm ruler) and it seemed to be slightly larger than 27.0, but my eyes could be misleading me. I have no micrometer to check it with. Another reason I thought it was 27.2mm was due to the frame being 531 tubing and upon research it said 27.2mm post size, but I may be wrong as to what I read or how I interpreted it.
I weighed the frame (with fork) and it was under 6.5 pounds; seemed much lighter than the Olmo (but it still has headset installed, and has Italian BB 70mm for what that's worth, and is a larger frame).
I will see if I can accurately measure the outer diameter of the seat tube to see what it is; I do have an old set of calipers that should work, and just measure the gap with my ruler. I assume that if it should be 28.0mm it will be slightly larger given the paint (correct?); maybe 28.5ish, if 28.6mm closer to 29mm. Just guessing.
Regarding the pantograph, I assume it is the builder and not the brand. I am definitely not familiar with most of these marks including the lug cut-outs. I certainly don't know what type of lugs they are. Most lugs look the same to me except the fancy stuff on some bikes; mine are all pretty run of mill on 4 different frames except specificcut-outs.
The COSME bike shop started in 1985 per their web page so would make this frame no earlier in manucfacture than 1984 (I assume they had some stock prepared before opening their doors in 85; especially if in early 85) if it is indeed one of their marketed frames. I still think the paint is original, but the decals (both sides of the seat tube) appear very new considering the wear and tear on the frame. I thought they were added since you would think there would be at least a headbadge remaining (or pieces thereof). Also, again without any real knowledge here, I thought the wrap over seat stays were odd and may provide some hint as to the builder or marque aside from the pantohraphs.
Thanks again in advance for any light that can be shed. I just kind of would like to know; otherwise I am still going to build and ride with pride regardless.
Edit: tried posting this 1/2 a day ago, but it didn't load (maybe same problem as photos?). Since then I I have used my 27.2mm post and it fits easily without any effort so I will go with that as being the size which as I mentioned earlier agrees with the 531 info I found online. It would appear that this is an 'odd' frame build if what was mentioned previously is the norm. Maybe that difference will help as a determinant for it's true lineage aside from the decals. Again, it is (to me) a lightweight well built frame of quality workmanship; I doubt I will see one when riding it around just like the Gaburro which people on the streets don't seem to have ever heard of.
Last edited by le bici di jaco; 09-04-21 at 02:15 PM.