The whole year I have belonged to this list, I have struggled with the meaning of classic. I don't like to disagree with Dale's year based definition, mainly because I am a rule follower and consensus builder. In the final hour, Dale's opinion must prevail. I write this to persuade Dale and others to come to my view, at least part way.
For me the classic elements must be MOSTLY in evidence.
1) The frame must be lugged, filet brazed or made during those years for which the age based definition overrides construction method. In other words, aluminum with any construction method would be permitted if it were made pre 1983, but a fine quality steel lugged frame would have to be included even if it were made last month. Any fine steel lugged frame could be considered if it has a high level of craftsmanship, rivaling the finest of the past, or even the average good craftsmanship of the past. The modern frames considered would have to have the spirit of the pride and style that we admire. For example a finely constructed frame would be out of the classic frame of reference if it, for example, had penis shaped lugs. However prideful the construction method, this lug style just had never been employed, and furthermore the spirit of the classic past would be violated. Penis shaped lugs just seem to come from a different and future mind think than, say. the fleur de lys.
2) Rims are a delicate and expendable item that requires replacement with newer substitutes. Clearly deep aero rims violate the sense and sensibility of the past box section rims. Mildly aero rims were in evidence in the early 80's, and so original mild aero should be considered classic, as should modern mild aero that fits the same mold.
3) Bar end shifters, down tube shifters and even (UGGH) stem shifters are all plainly classic. (Well maybe not stem shifters, I am not sure, but I am sure I hate them. Nothing could be less classic than brifters, STI, Ergo or whatever delicate garbage the industry tries to force consumers to swallow. I think I could swallow a downtube lever and safely eliminate it, but those brifters would certainly cause a trip to the emergency room.
4) Seven speeds should stretch anyone's limits but still be included as they were in evidence in those Reagan years. I honestly believe that 8 speeds came in the 90's though. Freewheels as well as freehubs were around, and anything that is 7 looks fine on a classic bike. Wide, wide rear frame spreads, seem out of place on anything classic anyway.
5) Clips and straps, Look and Time all competed for the early 80's cycling buck. Looks for me are just as classic looking as clips and straps.
6) Drop parallelograms!!!!!!! Slants are just as classic. We should not eliminate a derailleur just because it hangs at a different angle. Slants had long since made their appearance too.
In a personal note: I am now considering a few track bikes. One is a genuine early 80's model, while another is a Bianchi of unknown vintage. If you can't just look at it and see that it is or isn't classic without looking at a serial number chart, then it is classic IMHO. I would hate to buy the Bianchi and then find out that it was actually manufactured in 1984, and so I would be unable to wax poetic (and scientific) about its virtues and vices, here on this list. If I replace a tube on an old frame is it suddenly unclassic just because it sports a new tube? Will Sophia Loren be a child of the 2000's if she gets an artificial heart valve this year? Let's be flexible. Garth Libre in Surfside Fl. (a community designed and built up during the 40's and early 50's)