Tsnor, I set mine to one beat per stroke, manageable only because this metronome app goes as low as 10 bpm. My inexpensive music metronome I believe only goes down to 30 bpm minimum, so I really can't use it for rowing 1:1 SPM. You have a thought though...I wonder if using the metronome to lock in a SPM rate for a couple workouts--say, 26 SPM at one beat per stoke--and then slowly wean down by next setting the metronome at 52 bpm, then 78 bpm, allowing the body's natural clock to fill in. I may well try that, thanks. #VarietySpiceOfLife
Popcorn, I experience the exact same thing (especially when watching TV lol) regarding the unintentional variability, sometimes imperceptible. I think there are simple free metronome apps for Android and iOS that you could try. What the heck, give it a whirl and let us know.
GreenStratMan, that's interesting about the stock app metronome click being in rhythm with your creaking erg (I sprayed wd40 on my joint and the creaking never came back ymmv). This particular app that I'm using on iOS is EUMLabs Pro Metronome, and I cannot recall if I paid for it or not. It has, literally, about 30+ different sounds. I particularly like the voice counting "one, two' three, four, five" (can be set to any desired count up to 12 before repeating)...it's like having my own personal coxswain. LOL Although I think this metronome app serves my purpose, I know there are a bunch of metronome apps out there, so I'm sure many are great.

That is super cool about being a hypnotherapist. So you can really appreciate the soothing nature of relaxing while smoothly erging. I admit to a dislike of looking at the PM5 and ErgData while I row. I do it out of necessity, but I much prefer tossing a towel over the PM5 and iPhone once I get it going, then having my only feedback be from an external timer ("Alexa, set a countdown timer for 30 minutes"), and pacing myself only with the metronome. Please keep us abreast as you continue this experiment. I'm sure many other nuances yet to be discovered. Thank you