On Monday, June 14, 2021 at 7:27:35 AM UTC-7, James Carrington wrote:
On Monday, June 14, 2021 at 6:08:25 AM UTC-4, Rolf Mantel wrote:
Am 13.06.2021 um 21:35 schrieb Tom Kunich:

While there are still those who might think it useful I would like to
know why you think it would be useful and what sort of knowledge do
you think that it would impart that you could not detect simply
through your legs without the extra weight of $500 in your wallet?
I'd take a power meter for $100 or so, in the hope that I can see more
easily whether I'm slower than usual

a) due to a bad night's sleep (power low)
b) due to external factors (power normal)

As of today, I can tell easily whether I'm slow due to the wind (speed
difference after the 90 degree bends) but issues like "far too low tire
pressure" and "chain is in desparate need of oil" I only notice
indirectly (Monday after servicing the bike I'm significantly faster
than Friday before servicing the bike).

If the power meter is sufficiently exact, I'd use it to still my
scientific curiosity comparing the wind resistence with various setups
(on the drops vs on the hoods vs recumbent bike, one very full pannier
vs two half-filled panniers etc).

Similary, once in my life I bought a heart rate monitor for cycling
which confirmed that my "feeling good" was a close enough measurement,
and after a few years of bike computers with cadence sensor I'm now
happy with mobile phone GPS without cadence sensor.

Rolf
Power meters are incredibly useful as a metric for fitness and for targeted training. However, if you aren't a competitive cyclist it isn't of much more use than any other electronic gizmo. Since I am a competitive cyclist, I rely on one rather heavily for training. That said, my use of a power meter is exclusively indoor, since external variables like weather, terrain, and traffic often conspire to thwart outdoor efforts. Being in the sport competitively for over 30 years, I have a reasonably good sense of RPE. Besides that, while racing your power numbers are largely irrelevant. If you can go with an attack, you go. Watching a power number is no more than a distraction at that point. It's not uncommon to see riders both pro and amateur put a piece of electrical tape over a power display when racing. Sure, you can analyze the data after and figure out 'gee, no wonder I got dropped', or 'I really shouldn't have been dropped'. As Rolf points out, the data can tell you a lot about your level of fitness, either generally or if you're over-trained. As far as I can tell, there is no one in this forum (aside from me) who would use a power meter for its designed purpose.
James, this is pretty much what I've said, though I would add that power meters only tell you where you are in your fitness since you couldn't even be a pro or advanced racing amateur if you already didn't have the ability. So you really can't improve on your ability but tell how much you've lost over the winter. In a race in the heat of competition for a pro they are useful to stop you from over-riding your ability not that that seems to have stopped anyone as we've just seen in the Tour of Switzerland. I've never seen such block head moves in my life. How do you ride off from your team leader? How do you start a sprint from a km out?