"My guess is that the riders I was comparing myself against were using bigger chainrings like this one, or more likely those modern compact crankset-and-cassette combinations that give greater effective power. I’ve read that the power advantage of 52t versus 50t is about five percent, all things being equal, but honestly it feels greater than that. No longer am I forced to coast when I get going too fast. I’m finding it easy to maintain an 18 mph pace on the flats, with no huffing and puffing and general overexertion.

You know, the clues were all there. Other people were pedaling at the same rate, but they were traveling further with each stroke. Duh. It was the gearing. It had nothing to do with the number of gears or the lack of index shifting or any of those modern conveniences. I just needed a bigger front gear. And I discovered it by accident. I probably would never have figured it out if that triple crankset hadn’t been just a tad bigger.

That first ride, I was thinking holy cow the entire way."

I didn't see it in the thread above, so apologies if it's already been covered:

OP...A balance of aerobic and anerobic energy expenditure will get you to the finish line in the STP "faster" and may improve your finishing position next year.

Chain rings can have an impact, but I didn't see a rundown of Spinning vs. Mashing in this thread...IMO, it's a topic you might dive into or start a thread about.

PS- Spinning was uncommon in the 1970s.

​​​​​​HTH.