OK, the challenge was laid, and I accepted. The gauntlet is down. We'll call it the Bridge City challenge!
Can this Schwinn Sting be repaired without extraordinary methods? Can the system actually be beat?
I think it can. So I have volunteered my mad sciences to give it a go.
Here is what showed up on my doorstep.
Some rust, some worse, some not so bad, nothing a little OA bath and some polishing can't cure methinks.
BB rear

Not too bad here either.
BB front

Hmmm, this one has been ridden hard. Typical Schwinn Sting brazing cracks. The truth was BITD, if you were going to jump it hard, you should have bought an SX-2000/Sting Comp, which had thicker tubing, and didn't ever crack anywhere, ever. Stings were racing frames. Very typical crack location on a Sting that was jumped hard here.
Rode hard cracked brazing, left side head tube.

Of course, they also cracked around the seat tubes, ....right about........Here. (Cringe)
Left side welds.

And.....here. (Double cringe)
Right side welds.

And also ....by the holes here.....hey, this one isn't cracked here. If it would have been ridden just a little bit harder, it would have been cracked right about....here.

Well, if it was welded with the seat tube in place, I'm hosed, but let's be optimistic, and start by soaking it for a few days with some Kano Kroil, inside, and out.
Kroil.

......Any guesses, bets, or otherwise?

More to come, however, do you see what it is laying on? Yep, blueprints for a 50cc Ultimate 10-300 biplane. I have not built a plane in a while, and I need a fresh one for this spring, so I must be crazy to let this land "on top" of my blueprints!

Well, it's not getting priority status, it's actually getting sort of "co-priority, in between steps" status....

What 50cc engine for your Bipe? We run a area 51 In a 50cc yak and it runs great.