Originally Posted by
LibertyFLS
Isn’t a 2018 a modern bike?
I'm not saying it's not modern. I'm saying that it doesn't have way wider gearing than existed in the 80s. At least not how it's set up in your photos, where it has a 53-39 crankset and a cassette that appears to be an 11-28 or maybe 11-30, for a total range of about 370%.
Your new drivetrain's 53-11 top-end is significantly higher than was practical to put on road bikes in the mid-80s, but substantially lower gears than your ~39-30 were also very possible. For instance, a lot of long-cage rear derailleurs could tolerate a 34-tooth big cog and could wrap 38-40 teeth. This meant, for instance, that you could pair a crankset of something like 52-42-34 with a 14-34 cluster and remain completely within spec, which would give a 371% gearing range with a 1:1 low gear.
In 1973 a 24 was “big” on a freewheel which is what’s on my Falcon and the Campy NR jockey wheel touches it. On my SR I have a 26, wow!
NR and SR were short-cage racing derailleurs, and their mechanical design had made only slight incremental changes from the 1951 Gran Sport. Their limitations have very little to do with what was possible at the time.
Heck, even the limitations of the Gran Sport have very little to do with what was possible at its own time; derailleurs that could tolerate wider gearing than it had already existed for decades.
You're phrasing this as "way wider gearing than existed", but what you're actually describing is way wider gearing than was fashionable in the racing market.