Hey all - my wife, brother-in-law, and I are all in the market this spring for some nice entry-level roadbikes, and I'm thinking that being patient and watching Craigslist for some 80's bikes in need of a bit of TLC might be a great and rewarding way to go.

The thing is, I'm kind of a neophyte at this - I'd be a lot more comfortable buying a new bike, or an old motorcycle.

As I understand it, there are differences/incompatibilities from bike to bike on stuff like bottom bracket threading & size, hub width, derailleur mounting, shifters, steering stems, brakes, pedals, etc. etc. And what seems like a minor problem might turn into a major pain if I happen to have scored a "deal" on an oddball bike that needs hard-to-source parts.

What's the prescribed standard approach? Buy a bike, disassemble, clean everything, lube everything, put it back together with new tires, brake pads & bar tape, give it a tune and hit the road?

Is it stupid to buy an older bike with the intention of upgrading components (carbon fork, 700 wheels, STI brake/shifter, 9-10 speed cassette, tri bars, etc.)? I'm guessing that trying to retrofit modern components like this to a vintage bike would quickly end up as an exercise in frustration and a waste of money compared to just buying something new that has the desired features/components. I'm not looking to make all of those upgrades to a $150 CL bike - just trying to get a sense of what is or isn't eligible for upgrades over time.

Any info, advice, or guidance would be much appreciated.