Trsnrtr

You'll get a diverse set of opinions on the Stages cranks but I'm very happy with mine; I own two. My usage is pretty much what you are looking for. Accuracy isn't my goal as long as it's repeatable from an averaging thing. Also, it gives me work-related calorie readings though they are calculated strictly on the amount of work done so if you aren't pedaling, you get no increase in calorie calculations even if your HR is 185.

WhyFi

Oh, no - that would certainly be way more work. "Happy Bday" x2 is ~20 seconds, the current CDC recommendation for hand washing. My hands were less dirty than if I were to bare-hand swipe the bottom of any of my shoes.

Trsnrtr

My FB has been littered with CV backlash posts the last day or so. I listened to a psychologist a few days or so and he said we were nearing the end of our honeymoon season where everything is togetherness and we're going to get through this and that soon, the "me" side of human nature was going to start rearing its ugly head.

Trsnrtr

Hmm.. a little stereotyping going on there?

Trsnrtr

Trsnrtr

I own a P2M that I quit using. It's an original and eats batteries, relatively special batteries at that. It's in the scrap section of my workroom and will probably never see the light of day again.

WhyFi

That sucks - what kind of rate? I think that I've changed my battery (NGeco) once in the two years that I've had it. Typical coin-type battery that you can find at Target or the like, too.

MoAlpha

Yes. Apologies.

Trsnrtr

About every 4th ride. I bought it used cheap and that's probably why. It's an original and takes a CR2450N which fits slightly different than a 2450. I talked to support at P2M and they said to make sure and buy fresh batteries and NOT to buy from Amazon which I had, of course. Then, I tried to buy some at Batteries Plus but the guy said they were old that they might not work for long which they didn't. Anyway, I gave up and bought a second Stages.

bampilot06

would you sell it?

MoAlpha

Thanks. I saw lots of opinions from people using it that way in the course of my "due diligence" and still sort-of think it would do for me. The danger is getting into it and wanting more, as LAJ , in his insightful way, is predicting.

Actually, I don't think you get any energy credit for HR, except for the negligible increased demand of the heart muscle itself. As I understand it, once you estimate your metabolic efficiency (something like 20%?) it's all kJ to kcal.

MoAlpha

I'd need a new BB for that, no?

WhyFi

Yeah, that'd get old quick.

WhyFi

Power2Max is in the spider business, not the spindle business; they bolt on to cranks for every standard. Mine happens to be 24mm. What BB do you have?

Trsnrtr

Thanks, that answers a question that I've had for a long time. I know my Garmin output is ludicrous. Add an HR monitor and the calorie rate drops by half. Add the PM and it again drops about 25% but I'll never know for sure because the PMs are on my lightest and most efficient machines. Maybe the computer plus HR on my heavy machines is correct. I'd never know unless I installed the PM on my heavier machines like my gravel bike and then rode the same route for which I have records.

What I do know and I find interesting is the difference in calorie calculations from the PM when the conditions change, like winter clothes vs. shorts and no jacket. It's really obvious on into the wind vs. a tailwind, of course, and going up hill gives huge calorie readings. Standing helps, too, for a lot of burn over a short period of time.

Trsnrtr

Depends.

Edit: What WhyFi said.

MoAlpha

Aha. With the original rings? It's some sort of BBright-Shimano conversion, probably Wheels mfgr, from the look of the visible parts.

Trsnrtr

We need to go to messaging for this but I can tell you that it's an FSA Gossamer 165mm 50x34.

MoAlpha

If it's calculating kcal on power normalized to FTP or something, then you might be getting more credit for higher efforts. I think that's how Strava does TSS. I don't know if that's valid for metabolic measures or not.

My HR to training load software is pretty good as these things go, and uses time in HR zone, rather than average for the ride, but it still overestimates everthing, especially on long rides, because the HR for a given power output increases steadily with fatigue and the model doesn't include that. That's one reason I'd like even a half-cranked estimate of power. My wife just says, "You look terrible; eat something!" Probably just as reliable.

Velo Vol 

Do you mean just you leaving? You've got both "we" and "I."

Trsnrtr

I can watch the output on my Garmin during the ride. For example, on a tailwind and not pedaling, no calorie credit. I showed my wife just the other day that my calorie burn at our rest stop was XXX into the wind and that it would be 25% less or so going home on the tailwind. I was pretty darn close. I obviously spend too much time staring at my computer while riding.

Edit to clarify, you can watch calorie output change while riding. If the effort is high like on a steep hill, the rate goes up significantly. If coasting, the calorie number won't change.

Velo Vol 

Good time for a fresh start.

Velo Vol 

Or Miami.

BillyD

+100

The country would be a better place if those types of people just eradicated themselves.

WhyFi

Depends. Until recently, the vast majority of cranksets had spiders integrated in to the spindle, in which case you'd buy a compatible crankset with their spider installed (like I did with my Rotor) and possibly move the chainrings over to the depending upon hole pattern and BCD. Recently, a number of manufacturers have gone to separate spindle/arms/spider. If you have something like this, you can buy just the P2M spider, take your crankset apart and replace the spider and carry over the majority of your crankset.

Edit - oh, duh. I tracked down your R3 photo because I couldn't remember what crankset you have. It's the stock Shimano, of course - I was thinking of the FSA, but that's on the Ti bike. Yeah, you'd need a 24mm spindle like I have.