I have a 1989 Schwinn Spirit 10 speed which I've been riding as I get back into cycling. The components (Suntour) work okay given the age of the bike but I've switched out the stem and the seatpost to get a good fit. My original thought was that I would ride this while looking for a new roadbike. The more I think about it, the more I wonder why not upgrade this bike so that it would last me a while until I have the cash (and the riding experience) to justify getting a much better 'first' bike.

I was thinking about swapping out the old 27" wheels and getting newer, better but not extravagant wheels. Would that require updating the drivetrain? If so, would getting a used but more up-to-date group that wouldn't break the bank be feasible? Does this idea make any sense or am I looking at something that would be cost prohibitive to make any real difference? Thanks