When I got this bike (over 10 years ago now) I was told it was a Paramount....
Wasn't sure then, but didn't care as it was a softer ride than the Criterium series Cannondale I had just gotten rid of.
It was repainted before I got it, so decals are nonexistent.
Serial numbers don't make any sense from all the info I've gotten off the internet, so I 'm here asking for help.
I just want to know what I have, and maybe what it's worth.
The date code on the head badge indicates 77 or 87, I'm thinking 87 based on the Shimano 105 group, but the serial number on the BB has me very confused.

I've attached some photos.

"I" wasn't used in any Schwinn serial numbers/date codes from all the websites I've been to..
Which is why I'm so confused.

The aforementioned Cannondale had the same 105 group on it, with the same levers, and I bought that one new in 1987.
So if the component group is not contemporary, judging by the badge the frame is 77 (unless that was changed).
I'm wondering if the 8 on the BB means anything as well, and if the design/style of the lugs is a clue.
The assumption here is that the bike is a Paramount. I don't think that it is, and would like to know what it could be.
The Letour's had serial numbers on the rear dropouts, this has no other numbers on it.
I'm still wondering what I have.....

What kind of dropouts does it have?

I don't know Paramounts, but that doesn't look like one to me for some reason.

Dropouts are unmarked, definitely not stamped, most likely forged with integral der. hanger, can take a photo if needed.
Frame brazing is not silver, design of the lugs does not match any photos of any paramount I've seen, Waterford or Japanese.
I'm saying it's not a Paramount - but what is it?
Weighing it on the shipping scale at work it's 23-24 lbs - no heavyweight by any means.....
And I'm not the only one with a similar problem - see this thread
https://www.bikeforums.net/classic-vintage/408281-schwinn-serial-number.html

I'm also going to say it's a 1987 frame - based on the design of the head badge

https://www.re-cycle.com/history/Schw...nC_Badges.aspx

I know.. year and a half old thread, sorry for digging it back up.. I've got the same deal, only the stickers are still in place, I 've got a Schwinn Tempo.. Serial number is I632022 and I found a strange symbol and a "G3" stamped on under the head tube lug... I was trying to date it. It has 105 shifters and derailleurs, and is in pretty decent shape... from what I've found it kind of looks like a '83, but it's in far too good of a shape for that, and it doesn't look like the head badge matches (maybe an '84? The frame is Columbus Tenax steel (according to: https://www.re-cycle.com/history/Schw...nC_Badges.aspx) but there is nothing stamped in the head badge... it's pretty weird. It looks like an awesome bike and a mega craigslist deal for da free, I'm just curious about how old it is and I though I could share what I've found so far...

I believe Tenax only popped up around 85, 86, and 87 timeframe? Post some pictures and we'll see if we can track it down.

You may just have yourself a Schwinn Circuit. That is if you still own it. I put in a semi-detailed response in another thread that you linked this one to.

In Short: My Schwinn Circuit has Headbadge 0257 and SN I637223
Did you say your Bike's Headbadge Stamp is 0267 and SN I637212?
also, I have the "8" stamped on my Circuit like yours

Based on the somewhat unique Shimano 600EX headset the OP's bike was most likely a 1987 Super Sport, which was made by Schwinn in Greenville MS. The serial number format matches other Greenville built bikes at the time. It was probably repainted because Schwinn chose a rather unpopular color scheme for the bike that year: