My typical ride takes 30-36 minutes from day to day.
ONE ride does not make a definitive test.

However the OP got more speed today; placebo effect, being in the zone, a better breakfast, wind shift, or just maybe better gearing, we should be sharing his happiness instead of tearing him down. If it is the placebo effect nothing tears that down faster than scientific naysayers.

It's possible that it was the chainring. Some people are spinners, some are torquers. If in the past he was running out of rpm before he ran out of troque, than he would benefit from a higher gear. I agree that most people don't realize their potential because they try to get maximum speed in to high a gear, but that isn't true of everybody.

To the OP, if it works go with it. If it's only your imagination, who cares.

FB I must say you are right to point out the benefits of moderation and support. Looking at my own post I realized it started at the middle of a sentence, and that I left out the word scientifically. I've moderated it a bit but there's another dynamic going on here.

In reviewing my posts I see that I almost exclusively offered facts to counter false beliefs. That's important because not only the OP is affected by those false beliefs continuing, but all those who read the thread. I also offerered a lot of information on his wavering chainwheel(s) and support for his being open to learning and feedback.

What prompted my last post was that the OP suddently seemed to go back to the belief that the larger chainwheel increased his speed, and that he "proved" that was the case. In addition he refers to how much "tougher" it was to push the 52, which means he is not having that easy a time torquing. Even without the addition to my post (before 1/2 mph) I don't think my post was harsh, though I do see that the total of several non-supportive responses might feel like piling on.

To the OP - two mechanical concerns:

1. It's great that you did not have to move the front derailleur up - probably the shifting will be better, as it would have been a bit too high before. If the large chainwheel still wavers the problem is the spider - unless you have not done the procedure I recommended to check for a loose fixed cup, though usually you would feel that when pedaling hard as well.

2. You should check the chainwheel bolts for tightness after you have put in several miles, or if you begin to hear any high-pitched clicks when you pedal. It is not unusual for newly reinstalled chainwheel bolts to loosen.

This is exactly what I was thinking. I was never very talented at cardio but squats were my best weight lifting exercise when I was into that. I'm not serious enough about it to spend 90 minute a day on a bike, just trying to get to the burn and the "runner's high". 34 minutes was my previous best, so to get down to 33 on the 2nd day with the new chainring got my attention. The scientific thing was just a joke... wouldn't be using a cell phone if I was serious.