I want to take one of my old road bikes and convert it but can't decide which one. I've got an 86 Schwinn Tempo with stock components (a ho-hum Shimano drive train, Sugino cranks, Dia-Comp brakes, Weinmann rims, Columbus frame) and an 85 Trek 400 series with Campy components, Araya rims and a Cro-Moly frame. Both are road worthy now, although the Schwinn is my normal rider since I've had it for years and the Trek is a more recent acquisition.

Any thoughts on which of these should make the transition? I'm leaning toward converting the Trek, and migrating the Campy to the Schwinn.

This would be my first fixie...

ha...er...Both!

Go with the one you ride the most because after you get it fixed you wont ride the other at all.

Depends, IMO, on what kind of riding you think you'll be doing more of- fixed or geared. If you're going to do more fixed riding, convert the frame you like most. If geared, keep the frame you like most as it is and convert the other. If you're not sure you'll like fixed riding, don't remove any braze-ons just yet.

I'd put the Campagnolo on the bike I planned to ride more often. I'd also lean toward converting the bike that has the tighter clearance between the rear tire and seat tube.

I'd convert the Schwinn, leave that campy road bike alone.
Although what would really be the deciding factor for me would be which level of shimano and campy each bike has.

make the schwinn whichever configuation you plan to ride more.

but i only say that because im not a fan of trek bikes. plus they didnt give me a job i wanted. hahaha.

Unbelievably, but true, I've done each of them, in the same year, too. Well, the Trek was a 1980, but same diff more or less, see here:

https://www.fixedgeargallery.com/2004/e/cowen.htm

I really liked the trek, really comfortable and fit great, the Tempo was waay stiff, (if you like that kind of thing ), Tempo was about 4 pounds lighter in fixed trim.

i'd say that we would need to see pictures. hee.