I acquired another old Schwinn but, as per usual all the decals are fubar'ed. Maybe one of you historians can help..
It's probably a mid seventies but, I don't know for sure.... The serial # off the bottom reads SD402668 and, the number stamp on the badge reads 1024. It's a 12 speed 4130 chromemoloy frame. Any thoughts????

Your bike is probably a Japanese-made Schwinn assembled in either 1974 or 1984.

The headbadge number can be decoded as such: 102nd day (April 12) of year ending in 4. So April 12, 1974 or 1984.

There were various serial number formats over the years. Your format looks like the format S(month letter)(year number)(frame number) which was used for Japanese-made bikes. So SD402668 would be the 2668th bike assembled in April 1974 or 1984 in Japan. That's consistent with your headbadge number.

Post some pictures and it should be easy to tell if it is from the 70s or 80s. The model can be gleaned by looking at the catalogs once the decade is confirmed.

How do you know it's chrome-moly?

A 12 speed most likely points to 1984--- unless someone in the past upgraded the original 5 speed freewheel on a 1974 to a 6 speed Ultra or narrow spaced Suntour, Atom or Regina. However, with that said, IIRC, the four digit date code stamped in head badge did not become universal until 1975-76? My money is on 1984. Take a look here at this Findley-Cooper Page.

This is probably going to sound stupid but, it has the decal. I know it can be faked but, it looks like it's been on there a long time. Someone could have changed the free wheel from 5 to 6. It's easy I've done it myself. I have a 79 that is very similar. The 2 things that stand out are 1) the spoke guard is metal. That makes me think it's older 2) the suicide shifter is screwed to the frame. It's got Suntour arx derailures and, wheels. That probably got added later. Idk why I just like the old Schwinns!!! That what I stumble across most of the time. It was a freebie!!! To me free is good!!!lol

​​​​​​Oh, I thought all the decals were gone per your original post.

Still post pictures if you can. Should be quick to ID it with pics.

You'll have no argument from me on picking up old Schwinns. I currently have 3: a '95 Super Stock (BMX), '86 High Sierra, and '73 Sports Tourer. And I used to have an '88 Paramount. They're all cool bikes!

'84 LeTour is my best guess. Shifters will be bolted to the TOP of the down tube, rather than the sides.
Note the bike on the right.

You're right it's an 84 probably a Le Tour by the looks of it. The remnates that are left of the decals are yellow. I wish I could post a pic!!! The site won't let me take one from my phone. The 74s have a much larger spoke guard.

The Suntour ARX derailleurs point most likely to either the Super LeTour or LeTour (and take a look at the next page). What's the brand of the freewheel?

LeTour Luxe vs. Super Letour should be easy to sort, based on the crank (triple vs. double), and the paint color.
It likely isn't a '74. The only lugged frames that Schwinn sold in '74 were the LeTour, Voyageur and Paramount.
The 74 LeTour wasn't made of chrome moly, the Voyageur that year had chrome lugs, and the Paramount... well those are obvious and easy to spot with chrome Nervex lugs.
Your '84 LeTour tubing decal would look like this:
Pay no attention to the Schwinn downtube decal on the photo above. I removed the original yellow and white graphic and replaced it with the decal from about '79.

It is too bad more people don't have access to cameras.

Hilarious. I did the exact same thing to an '84 Tempo that started with the same wretched yellow/white decals. Even chose the same replacement decals.

HA!

That's the decal in the exact same spot. It's a double crank set Surgino BT. It's got Weiman 614 stainless wheels I didn't think to look for a brand name on the freewheel.

Yep. Sounds like an '84 Super LeTour like @pastorbobnlnh suggested.

How many teeth are on the small ring? 36?

The factory rings on that 86mm BCD Sekae Super Custom crank were 50-42-28. As shown in the photo, I'm currently running 50-40-28.

One thing that I don't think has been mentioned, is that the manufacturer was Bridgestone.

I'm not one to disagree with you lightly Tom, but I'm pretty sure mine was brazed in Greenville, MS.
I believe a number of other Schwinn models were made in Japan that year, however.

Sorry, I thought I'd read that it was Japanese model.

Well thank you for enlightening us that models made in Japan during this period were made by Bridgestone.
I would have just assumed Panasonic, like it was in the mid-70's.

They could be from either. The serial number format will distinguish between the two.

Sorry to bother you but, what size spacers did you use on your triple and, am I going to be forced to change the BB going from double to triple? I got the exact same front and, rear derailleures you do.

Not sure how thick the spacers are... they're the factory ones. I can measure them sometime in the next day or two. When I took it apart to refurbish it, I was a bit surprised that all three rings used the same bolts.
As far as the BB spindle length, I would assume you'll need a longer one. I never measured the length when I had it apart.

Third-ring spacers appear to be 5mm thick.

Probably a good thing you don't want to accidentally capture someone else's soul ...