DaveWh
November 2, 2019, 2:39pm
68
Nice work! I’ve speculated on this before. Interesting to see that you’ve measured a difference.
FWIW, I think the Assioma pedals are measuring accurately, and others are off.
As I mention in one of the posts below, a similar issue arises with oval vs round chain rings.
Ironic that we all think power meters bring an objectivity to measuring our work effort, whereas we may sometimes be fooling ourselves and RPE is more accurate!
There’s two possible reasons here - with the first I think being a lot more likely than the 2nd.
You find low inertia/speed riding (small ring) easier than high inertia/speed riding (big ring). This is true for me also. Others, however, report the opposite. This likey is due just to different physiologies between riders.
Your trainer (or power meter) measures power differently bwteeen high inertia and low inertia riding. This would obviously be a flaw in the power measurement, but there is…
Check out the thread linked to above about big ring vs small ring.
Separately, I actually think that some trainers (and power meters) measure power differently between big gear vs small gear. I’ve seen enough people talk about pretty noticeable differences in how easy a workout feels between big gear vs small gear. And I suspect it’s not all due to inertia.
I think it’s related to how power meters can sometimes measure power differently between oval vs round chain rings.
In mathematical term…
I’ve thought about this for a while to try figure out why there is a difference between high vs. low inertia riding. I believe it comes down to the variation in angular velocity over the course of the pedal stroke, and how that’s different between high vs. low inertia riding.
I’d love to see the angular velocity data that maps to the torque data from the screenshots you took from Shane’s video, but since I don’t have that data, in good scientific practice, I’ll propose a theory, and hopefully s…