I'd like to find something fairly comprehensive, so it would probably have to be an online reference. Is there such a thing, or things?

more vintage focused but velobase is the closest I know about VeloBase.com

Manuals & Technical Documents

This will give you everything on Shimano parts and tech docs. Good luck on other manufacturers!

Campagnolo has user manuals and parts catalogs going back to '94

https://www.campagnolo.com/US/en/Sup...#documentation

Back in the day the Sutherland's Manual was our bible. Andy

For a sort-of historical reference, the Bike Pro catalog: BikePro.com / the Buyer's Guide / Bicycle Parts at their finest!, 2015 is good for '90's era components.

The thing is, what are you looking for? What parts work on what frame? That's nearly impossible because bicycles are infinitely fungible: parts and components can be swapped across eras with impunity given a little knowledge and perhaps some tinkering.

Here's where I'm coming from. I spent most of the '80's working in the bicycle business, working in shops and parts warehouses, finishing up at Bike'alog, an information service for bicycle dealers. We tried to collect as much information as we could and cram it into our database. Because of this, I'm aware of what fits what for that era. I've kept up with things somewhat, but my knowledge of some of the later variations is a bit spotty.

For instance: in my garage is a 1977 Schwinn Superior, rebuilt and now equipped with first series Shimano XTR components from the early '90's. It took a smidgen of finagling, but everything works perfectly together and the bike is a pleasure to ride. Certainly the Schwinn company never imagined the changes in bicycle design and component selection that would happen in the decades after the frame was produced, but since bicycle "standards" stayed relatively consistent putting this bike together was straightforward.

I see that you are a Lightning P-38 recumbent owner. Are you looking for something for that bike? Here's mine, bought in 1990, ridden through the '90's, rebuilt multiple times. I broke it in half (a design weakness of early extra-large frames) and it was repaired by Pat Franz at TerraCycle. It's a garage queen now since I have several other bikes that get ridden.

Thanks everyone for the replies. Referenced sites bookmarked.

I maintain a Lightning P-38 and a Catrike Pocket (wife's), so these references should do. I want to eventually upgrade the components on the Catrike as they wear. I'm pretty happy with the P-38 as it is, though I might be interested in upgrades if they had some real advantage in terms of maintenance, durability, or function.

Thanks again!

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...Velobase is good, but for sheer wealth of information on derailleurs specifically, (some of them are a little esoteric,) look for a documents stash on your specific model on Disraeli Gears. This has been a huge help for me several times when puzzling out stuff from the '50's and 60's.

Another source that has helped me is velo-pages.com .

Got them, thanks!

Got it. Aside from suspension bits (the Lightning fork or the Catrike front knuckles- I'm not saying you have those) recumbents use "standard" bike parts so repairing or replacing should be straightforward. Parts keep evolving but a lot of stuff is still available if you know where to look. For instance, I built my new RANS Phoenix with a triple crank and 9-speed cassette. These are generally "obsolete" but I had no problem sourcing brand-new components that bolted together without a problem.

If I want to get wacky and try electronic shifting I'll probably try the Xshifters: https://www.sportcrafters.com/products/xshifter . I watched them in action yesterday and they look slick. They'd eliminate the miles of cable and housing on the Phoenix.