Originally Posted by
Salamandrine
Given this bike is 600 equipped as is, meaning nice 'groupset' already. Most likely by upgrade we are talking cross grade at most. If you have a box full of modern parts fine, but to refit the bike from scratch you'd be looking at an ultegra group, set of wheels, and a frame realignment. I figure that cost at least $1200+ if bought new from online retailers, not including labor.
Right. As has repeatedly been said here, newer does not equal "better."
I don't even use "upgrade" for something like replacing downtube shifters with STI or Ergo, or clips and straps with clipless pedals, or even 6-speed with 10-speed. I reserve the word "upgrade" for a clear improvement of quality. That's what it means: Up (in figurative) grade. I would use it for replacing a 105 derailleur with a Dura-Ace. I would not use it to describe replacing a Nuovo Record derailleur with a 105.
The term "update" is a better word for putting newer stuff on, because that's what that means: Up (in) date.
Of course, one can do both things at once. But better not to conflate them.