Originally Posted by MichaelW
For me , the easiest way to identify a quality frame from low-end when you dont know brands and labels, is to take a quick glance at the rear dropouts. If they are plain stamped steel, it's low-end. If they are moulded (investment cast), with changes in thicknes, then its probably a quality bike.
The forged vs. stamped drop-out rule isn't always true though... My best riding bike, otherwise nicely built out of top grade stuff (rare series of Nervex lug & full 531 DB) has stamped drop-outs. It also has a beautiful enameled headbadge, super comfortable "pencil stays" and a longish wheelbase. It wasn't a dumpster find, but was overlooked at a bike swap meet, probably due to having stamped drop-outs. Another frame I have, a fillet brazed Jack Taylor, also has what appear to be a cheap, stamped drop-out. While they probably were cheaply stamped, they're stamped Campagnolo cheapies, and work just fine.
As for the dumpster diving thing, I say take all you can get with those drop bars, and decide what's really junk when it's in front of you... You can always stick the stuff back in the trash can. BTW- my best dumpster finds were a '80 753 Raleigh Team frame (no parts on it), and a '60ish Bertin frame (Reynolds 531 DB), also with no parts. I was happy to climb in & pull each one out...;^)