Bought this frame from a guy. Don't know who made it. He told me it's a 1980s Vintage frame. Thank you all!

Serial number: C524185

Short slot horizontal rear DOs, Dual bottle mounts, under BB cable guides and brazed on TT brake cable guides do point towards the 80's..... Looks to be good quality from what I can see so far.
Will need more close up detail shots of things like the frame lugs, fork crown, seat cluster, brake bridge and drive side rear dropout area to help people here figure out what it is.

Chombi

Images attached. Thank you!

Serial nbr format could be Miyata, but then it would be from '75, which is a bit early for those braze-ons. Or maybe 2001, if they restarted with A after Z.

Anyway, whatever it is, it looks pretty decent. Congrats!

looks similar to a couple of trek frame i have had from 83 and 85.

just a guess.

I don't see anything unique enough on the frame to immediately ID it, but notable features on that frame that someone here might recognize:
Tubular shaped top tube cable guides.
Plain Bocama-like lugs that seems to have more of a backswept cut at the head top and bottom lugs.
Something slightly different seems to be going on with the shifter lugs (is it damaged or is it Shimano type).
The plain treatment (no reinforcing diamonds) of the brake bridge and its center that looks like it has brazed on thick washers and not a block.
The tubular style cable guides under the BB.
Chisel point stay ends at the rear DO.
Unusually long looking chain hanger on the right chainstay.
Could you see any sign of a name on the rear or front dropout faces?
What threading is the BB? Do you happen to still have the BB cups that was originally on the frame?
Unfortunately, the rather thick repaint might be covering up some critical evidence on the frame's ID. Original color of the bike might also give a sign to what it is.
Otherwise, it looks like a good quality frame. Certainly worth finding out what it is and building up.
My wild guess at this point that it could be Japanese.....
BTW, the marks on that seat tube you are showing on your pics could be just be the front derailleur mounting band distorting the paint when it was mounted before the thick repaint was dry. Don't think you need to worry about it.

Chombi

I'll tell you exactly what it is. A nice frame!

Chombi,

I don't have the original BB cup from the frame. I measured the BB and it came out to be 68mmx34mm. I also measured the spacing from the rear dropouts and it came out to be 126mm.

The stamped number of the BB bearing cups would have given you the threading information that could also close to determine what region of the world the bike was made in... The 68mm width is pretty typical, not sure about the 34mm measurement....
126mm dropout (6/7 speed) spacing measurement at the rear indicates the bike is probably from the early to a little bit later than the mid 80's

Chombi

+1 on Japanese/Orient make. The forged DOs with adjuster holes make it appear to be a higher end 80's racing bike.

It looks like a Centurion LeMans to me. Not sure that the serial number matches though.

I'm not sure what it is, but that chain hanger on the rear stay is unusual. The cylinder part of the chain hanger is longer and thinner than the ones I'm used to seeing. Might be a clue. The eyelets on the fork and rear dropout suggest a sports model, rather than a purebred racer.

I agree. It must be a mid-level sports with the forged DO's and all. I don't believe that the LeMans' had forged DO's.

1985 Bridgestone manufactured frame.

You are good, T-Mar. Real good.

600?

Rb-t? Rb-3?

I took it to a LBS today and the guy told me it's a Univega. I asked him to help me build it and he said all the parts and everything to put it together costs about $300. He said he'll call me tomorrow to let me know. I left the bike frame there so that they can find the parts for it. But $300? Really?

Did he say which parts?
$300 to me would be late 80's Shimano 600 or equivalent in really good condition, with wheels of comparable quality, serviceable tires/brake pads, and new cables/housing. Not unreasonable IMO if that is the case.

If, however, it is a mish-mash of random vintage parts of varying quality and condition, I'd want to get more details and would suss out other options if the mix doesn't fit the bill.

Almost everyone on here knows where/when to stock up on cables, casing, tires... for pennies on the dollar compared to walking into the lbs and paying retail. Cheap alloy wheel set $80, normal sealed bb $25, cranks $40, 2 tires+tubes $45, bars+stem another $40, seat, seatpost, bar tape, brakes, levers, shifters, freewheel, chain,... It adds up real quick putting together a bike piece by piece when paying retail. If that's the case watch e-bay for a period correct gruppo buy it and just have them install your parts

If you have someone else build it, it will be too expensive. Even if you build it, it's not worth it unless you have at least some of the parts on hand already.

Normally, I would defer to a knowledgeable person who has the opportunity to examine the frame in person, but in this case I take exception. A Univega frame of this apparent period would almost certainly have been manufactured by Miyata. However, if this were a Miyata manufactured frame, the serial number would place it circa 1974, predating the existance of the Univega brand. Given the era and serial number format, a Bridgestone manufactured frame is the best candidate.

Reminds me of my 1983/4 Schwinn "Super Sport" - here's a pic of the guides under the BB:



and the hanger looks v. similar, as does the crown of the fork, and the rear drop-outs.

Here's a link to some more pics of mine: Super Sport

Yours is a nice frame! I was given a Schwinn Le Tour (just the frame) in the same colour as yours and I'll post more pics when I've finished restoring it!

First off, that's a really nice bike that you have. Second, now you make me think if what I have is a Schwinn Super Sport or not.

Those cable guides were standard items used by many manufacturers. That Schwinn has an entirely different serial number format from your bicycle. The Schwinn has a serial number format that is consistent with Matsu****a (i.e. Panasonic).