GCRyder

I would not be so quick as others to belittle this frame. I own three Univegas from that era. Lawee saw fit to use dozens of different model names over a fairly short span of years, so I'm not familiar with the "Maxima Sport." What I see right forward of the seatpost in the photo, however, looks like it might be the "CTB- Chromoly Triple Butted" sticker that went on some of their nicest, lightest frames. It would surprise me to see that on a bike with suicide levers and stem-mount shifters, but nothing really shocks me when it comes to Univega. Lawee put some really weird component mixes on some really nice frames, for some reason, and the orientation of those sidepull control arms makes me suspect that this might be one of those strange amalgamations. As long as you don't have unrealistic expectations - this bike is never going to be a 15-pound wonder-climber - there's no reason not to make some changes. If it does happen to be a gas-pipe frame, on the other hand, I'd tend to agree with the "naysayers."

The "upgrades" you're suggesting, though, might not really be improvements. Changing a fork, for example, is a hit-or-miss proposition that I would advise against. That fork is a 1" threaded-steerer design, and was built for 27" wheels. The headtube on the frame limits you to a 1" replacement. You could theoretically go to a 1" threadless fork with a new headset, but just going to a threadless system is not an improvement. Forks you'll find for that wheel size won't be threadless, and most won't be as good as the fork you've got. If you use a fork built for 700c wheels, you'll be messing with your steering geometry, and probably wouldn't like the result. If you want the more modern, lighter 700c wheels, you'd be better advised to just put them into this frame and get longer-reach brakes.

This frame probably uses nutted brake-mounts, at least in the rear, and I'm not sure if the reach of your 105 brakes will fit. There have been several variants of "105" over the years, also. If I had the levers available, I would definitely ditch those brake levers and replace them with aero levers. It also looks to me like a 105 crankset would be an upgrade. That would probably call for a new bottom bracket, of which a sealed-bearing cartridge would also be an upgrade. I'm assuming the current cogset is on a 6-speed freewheel, with something like a 14-28 spread. A short-cage 105 might be marginal on the 28.