Why the Stages meter is good enough for me

meanredspider

I know this is verging on trolling for some people - in that I can predict the responses before I've even posted. And I also want to put a big caveat on what I share in that it's far from "scientific" but it is also typical of my experiences of the Stages meter. It is also my opinion and reflects my needs only Blimey - I hope that's enough - but I know it won't be - that's OK.

I did two loops: last Saturday morning and this Saturday morning of pretty much exactly the same route (due to the road being dug up in Weesp, it was slightly different in a residential back street area)

Over a distance of 62km, there was 0.3kmh difference in average speed (30.9 vs 31.2 - it's actually slightly warmer today), 1bpm difference in avg HR (and 3bpm in max), 1rpm difference in avg cadence and 1W difference in avg power (and 1W difference in NP too and 2W difference in max avg power (20min)). In fact, by far the biggest variation was in elevation recorded by the Garmin 800. There are bigger differences between the way that Garmin connect treats precisely the same data and Strava (not benchmark systems I know). And, sure, avg power is a pretty low hurdle of precision.

But my point is this: for a lot of us, this is good enough: I know that next Saturday morning, I could target the same power and get pretty much the same results. Or I could push a bit harder because I'm feeling pretty good. I know that some people need more - I've never criticised any other system - but there's also a segment of the market for whom this is just peachy

NeXXus

Great.

Tom Dean

Fair enough if you think it's good enough. Your speed etc don't tell us anything about the reliability of the power data though.

imposter2.0

Did it need a new thread? Or maybe just add to the old one?

meanredspider

Tom Dean wrote:

Fair enough if you think it's good enough. Your speed etc don't tell us anything about the reliability of the power data though.

I know - short of riding against a calibrated standard, I'm not sure what would? I don't need to know if it's really, say, 300W. All I need to know is, if it says 300W this week, that's pretty much exactly the same as the 300W it said it was last week. I know that the data is only broadly indicative of that (same route, same speed, same PE, same cadence, same conditions, delivered by the same power) but it's quite a few variables that line up (I'm actually pretty surprised how consistent I am)

meanredspider

Imposter wrote:

Did it need a new thread? Or maybe just add to the old one?

Thought about it but that was Stages vs P2M. The only facts I have on P2M is that it would be a PITA to swap between my bikes due to different chain ring sizes and that it was going to be a month before it arrived.

mulletmaster

The fact that you feel that 2 loops at slightly different speeds using almost identical power is evidence that a stages is a useful pm let's me know it is also sufficient for your needs. Using such slack selection criteria might I recommended a powercal which could more than cope with those requirements.
For other people, that wouldn't suffice. I had a stages and it was total garbage, unreliable inaccurate and non precise. Thankfully they were great at replacing it, I get the impression they have done that a few times. Power2max ever after. Zero skin off my nose if you are anyone else wants to use one, just don't try and tell the rest of us they are equivalent to any kind of crank pm without expecting objections.

frisbee

mulletmaster wrote:

The fact that you feel that 2 loops at slightly different speeds using almost identical power is evidence that a stages is a useful pm let's me know it is also sufficient for your needs. Using such slack selection criteria might I recommended a powercal which could more than cope with those requirements.
For other people, that wouldn't suffice. I had a stages and it was total garbage, unreliable inaccurate and non precise. Thankfully they were great at replacing it, I get the impression they have done that a few times. Power2max ever after. Zero skin off my nose if you are anyone else wants to use one, just don't try and tell the rest of us they are equivalent to any kind of crank pm without expecting objections.

Out of interest, what were you comparing it against to determine that it was inaccurate?

meanredspider

frisbee wrote:

mulletmaster wrote:

The fact that you feel that 2 loops at slightly different speeds using almost identical power is evidence that a stages is a useful pm let's me know it is also sufficient for your needs. Using such slack selection criteria might I recommended a powercal which could more than cope with those requirements.
For other people, that wouldn't suffice. I had a stages and it was total garbage, unreliable inaccurate and non precise. Thankfully they were great at replacing it, I get the impression they have done that a few times. Power2max ever after. Zero skin off my nose if you are anyone else wants to use one, just don't try and tell the rest of us they are equivalent to any kind of crank pm without expecting objections.

Out of interest, what were you comparing it against to determine that it was inaccurate?

Yup - I'm interested in that too. Given all the key parameters were within 1% of each other - if I'd said that I was comparing two different meters, the view that they'd have been pretty comparable. Covering the same route at the same speed at the same PE at the same cadence at the same recorded power is what you'd hope for. It isn't my selection criteria - I've long since selected and have absolutely no regrets. What would you expect differently from your P2M? And, in contrast to what you have written, I've not claimed anything about their equivalence or otherwise to other crank PMs (where did I say that?). I would challenge you to show me that your P2M is better (only because I'm interested to see how you do it)

RChung

If the Stages meets your needs and you're happy with it you shouldn't care what we think -- at least, about the Stages. Maybe you might care what we think of you for starting this thread but the Stages? No worries.

meanredspider

RChung wrote:

Maybe you might care what we think of you

That's so funny, Robert. "Road - Training, Fitness and Health" is the vipers' nest of BR forums. Nobody posts on here if they care in the slightest what other people think of them

RChung

Excellent point. Carry on, then -- and so shall we.

janesy

now now children, use what ever you want but dont preach that yours is the best.

Team4Luke

Stages by it's nature and price has brought a decent level of power measure to the masses and clearly upset everyone else that thinks their device is more accurate, better, more pro, reliable etc etc.
You can not measure your performance off one single variable, and that includes power. If you train at 300w one week and 300W many weeks later it is not a given that the two are same, ensuring the device is set up and reset every time must be done as well. The body is very smart and will adapt and change to fitness, health, training load etc, if you are on a bad day or a good day for that matter it does not follow that you have genuinely lost or gained power.
Use all available information to assess potential gains.

Tom Dean

Team4Luke wrote:

You can not measure your performance off one single variable, and that includes power.

Yes you can. Performance is performance.

Team4Luke wrote:

If you train at 300w one week and 300W many weeks later it is not a given that the two are same,

- that the two what are the same?

Team4Luke wrote:

ensuring the device is set up and reset every time must be done as well.

yes, people actually do this!

Team4Luke wrote:

The body is very smart and will adapt and change to fitness, health, training load etc,

'the body will adapt to fitness' what does this mean?

Team4Luke wrote:

if you are on a bad day or a good day for that matter it does not follow that you have genuinely lost or gained power.
Use all available information to assess potential gains.

Why would power on a good day not be genuine?

whoof

I'm sure that I heard somewhere 'Don't put you data on the Stage Mrs Worthington' but that was a while back.

meanredspider

whoof wrote:

I'm sure that I heard somewhere 'Don't put you data on the Stage Mrs Worthington' but that was a while back.

That's the worst joke I've heard in a long time!! Chapeau

Alex_Simmons/RST

Team4Luke wrote:

Stages by it's nature and price has brought a decent level of power measure to the masses and clearly upset everyone else that thinks their device is more accurate, better, more pro, reliable etc etc.

My devices are more accurate and reliable but I'm not upset about it.

Team4Luke wrote:

You can not measure your performance off one single variable, and that includes power.

Don't conflate factors that influence performance with the measurement of performance.

Team4Luke wrote:

If you train at 300w one week and 300W many weeks later it is not a given that the two are same, ensuring the device is set up and reset every time must be done as well.

Well it's not a given that a Stages will be the same since nobody knows what their pedalling asymmetry is like day to day (unless you measure it day to day), but I can assure you that when my meter says 300W today and 300W a few weeks ago, it's the same. Precisely and accurately.

You do realise you should set up and reset the Stages as well before every ride? It's a 30-second check on most meters and a basic operational activity. Mine takes about 10 seconds to do.

Team4Luke wrote:

The body is very smart and will adapt and change to fitness, health, training load etc, if you are on a bad day or a good day for that matter it does not follow that you have genuinely lost or gained power.

If your meter is accurate then yes it does mean you have gained or lost power.

Don't conflate the reasons for variations in power with variations in power.

Team4Luke wrote:

Use all available information to assess potential gains.

Sure, but in order to do that objectively you need to know that the power measurement is consistent and accurate, else you can't be sure whether the variance in power was due to a measurement error or something else, or a combination.

meanredspider

Alex_Simmons/RST wrote:

Well it's not a given that a Stages will be the same since nobody knows what their pedalling asymmetry is like day to day (unless you measure it day to day), but I can assure you that when my meter says 300W today and 300W a few weeks ago, it's the same. Precisely and accurately.

Alex - can you share some insights/data into how much of an influence you see this L:R balance brings in variability? I'm not saying that this applies to you, but lots if people come on here claiming various things but come up very short when asked to demonstrate their point of view. This frustrates me as I like to learn - especially where I'm wrong. You are normally much better.

Now I'm building a cohort of data with the Stages over several of the regular rides I do (60k and 160k) and I'm seeing quite some consistency in the average power vs average speed (to 1-2%) If there was a significant shift in my L:R balance, I'd expect that to show up even in something as blunt as average power and speed - especially in these different distances.

Alex_Simmons/RST

meanredspider wrote:

Alex_Simmons/RST wrote:

Well it's not a given that a Stages will be the same since nobody knows what their pedalling asymmetry is like day to day (unless you measure it day to day), but I can assure you that when my meter says 300W today and 300W a few weeks ago, it's the same. Precisely and accurately.

Alex - can you share some insights/data into how much of an influence you see this L:R balance brings in variability?

Here are just a handful of links to study abstracts to emphasise this point about asymmetry being both normal and variable:
http://www.ncbi.nlm.nih.gov/pubmed/979569
http://www.ncbi.nlm.nih.gov/pubmed/10460126
http://www.ncbi.nlm.nih.gov/pubmed/17369798
http://www.ncbi.nlm.nih.gov/pubmed/21055708
http://www.ncbi.nlm.nih.gov/pubmed/24509507
http://eric.ed.gov/?id=EJ990074
http://www.jsc-journal.com/ojs/index.ph ... h%5B%5D=15
http://www.archives-pmr.org/article/S0003-9993(04)00014-0/fulltext
http://www.researchgate.net/publication ... fe4394.pdf

The last two links are full text. I leave it to you/others to review the full papers where available.

BTW - average power over whole ride is a pretty low standard for assessing such things.

janesy

im playing with my position and id go as far to say im in bike fit hell!.
my point is that my left / right balance is changing on a daily basis due to position changes. even if i go on the drops it changes. or lean my fore arms on the bar in a TT position.

im going to bike science today but im sure it wont level out the imbalance as described.

Alex_Simmons/RST

janesy wrote:

im playing with my position and id go as far to say im in bike fit hell!.
my point is that my left / right balance is changing on a daily basis due to position changes. even if i go on the drops it changes. or lean my fore arms on the bar in a TT position.

im going to bike science today but im sure it wont level out the imbalance as described.

Keep in mind your objective is to achieve performance improvement, not symmetry.

meanredspider

Alex_Simmons/RST wrote:

Here are just a handful of links to study abstracts to emphasise this point about asymmetry being both normal and variable:


BTW - average power over whole ride is a pretty low standard for assessing such things.

Thanks - I will take a look. I have said several times that I recognise average power is a very low hurdle. That said, achieving anything higher is vastly more involved. And, if the issue is a significant one, I'd expect it to start to show up as variability in my results and, honestly, it doesn't.

ETA - most of the papers (that I could access at least) just confirmed that there is asymmetry - I have no doubt about that. What I was hoping to see was the variability of this asymmetry within riders day-to-day - so, if I favour my right leg 5% today, will I favour it 10% next week and 2% the following week? Provided it doesn't change much, it really doesn't matter (to me). Does anybody have some data on L:R balance from proper L:R systems (I'm not sure those that only measure at the crank and estimate L:R based upon crank position really count) that can show that their L:R balance shifts a lot from day to day?

Alex_Simmons/RST

meanredspider wrote:

ETA - most of the papers (that I could access at least) just confirmed that there is asymmetry - I have no doubt about that. What I was hoping to see was the variability of this asymmetry within riders day-to-day

Keep reading... it does.

Indeed in some cases the day to day variability makes some experiments difficult to interpret.

The level of variability is individually variable, and also depends day to day on various factors such as fatigue, cadence, power etc. How much variability in your asymmetry exists is only answerable by measuring it.

janesy

Alex_Simmons/RST wrote:

janesy wrote:

im playing with my position and id go as far to say im in bike fit hell!.
my point is that my left / right balance is changing on a daily basis due to position changes. even if i go on the drops it changes. or lean my fore arms on the bar in a TT position.

im going to bike science today but im sure it wont level out the imbalance as described.

Keep in mind your objective is to achieve performance improvement, not symmetry.

Thanks Alex - yes agreed. I'm in some pain though Not going in to any details about my bike fit yesterday but am much more comfortable but lots of work to do. powermeter is reading 50/50 more or less. but as you said thats not the objective. Comfort = performance. I just happen to be a little more symmetrical as a result.