Power Meter for the Masses?

slowbike

Grill wrote:

Oh it might be accurate on one side, but the data quality is poor (see my last post, I have one and it's not even close to my P2M). If you haven't heard anyone complaining then you haven't listened to any coaches out there.

Ah - so it's accurate on one side ... that's good to know.

Data quality is poor? Spikes, dropouts, different to P2M ..

well - sounds like you've got a duff unit or duff head - the only time mine has dropped out was when I put my Garmin in my back pocket (trying a feature out on a different unit - not related to Power) - fair enough that it can't reliably transmit through my body ..
Spikes? Not had that.

I just don't recognize the errors that you're reporting.

Leg differences? If absolute power mattered then yes, I can see theres an issue. If you've got a major imbalance then yes, I can see that a PM that records both legs could help. But for the majority of us, who are only dabbling at it - left sided power and recording the change in output is sufficient.

Btw - my Stages power numbers are comparable to the turbo unit and produce similar numbers to a wattbike - and a very rough comparison to others using different PMs - are equally comparable.

Actually ... it's best coming from DC Rainmaker

https://www.dcrainmaker.com/2013/06/sta ... pdate.html

For me, I have no issues in using any of the power meters I’ve used in this review – including the Stages. I do in fact from time to time pick different ones, and the data is generally similar enough that there’s no discernable difference. Further, in some situations (such as nonstop climbing with shifts in temperature), the Stages simply performed better than two other units. This likely due to its automatic temperature compensation algorithms.

As for Stages being left-only and doubling the power, for me (and again, just me), I’m just not seeing any issues there. It’s possible that others have larger discrepancies, or that those discrepancies could vary. But in my case it seems pretty consistent across a wide variation of rides and riding conditions.

I think probably the biggest takeaway here is that no particular power meter is perfect. Anyone who says that there is, is sadly mistaken.

Given all that, here’s the updated Pros and Cons table:

Pros:

– Cheapest direct force power meter on market today
– Easy to install. Silly easy.
– Tons of crank compatibility options
– Accelerometer based cadence measurement works really well
– Utilizes standard CR2032 user-replaceable battery
– Automatically compensates for temperature changes
– Lightweight – 20g

Cons:

– Left leg dependent, simply doubles left leg power
– Total power could be highly impacted by your left/right distribution (but I didn’t see this)
– No method of end-user calibration validation (for advanced users)
– Doesn’t support Rotor cranks/arms as of today, or carbon crank arms

That's just a snippet from his Final thoughts ... there's a huge page on the testing he went through ..
So excuse me if I place more confidence in his thoughts than yours..

Of course, if you wish to counter his data - then feel free....

meanredspider

Grill wrote:

So P2M, SRM, PT, and now Infocrank can make both road and track PMs, but Stages can't? Nope, doesn't gel.

And Stages data is awful. Ask your coach what he/she think of it as compared to other systems.

But I still don't think you've quite grasped it. I can swap my Stages between bikes pretty much as quick I could swap rear wheels. I can run it on any bike type (provided it is the same fitment - my PM is Shimano 105 - it'll probably fit half the road bikes in the country) regardless of chainring size or number of speeds or wheel type. I can stick it in my pocket. It doesn't need any complicated calibration nor does it need any complicated torquing. It's simple and easy.

I don't have a coach.

I ride for pleasure. And fitness.

I want to know how hard I'm working. I want to know if I'm fitter this month than I was last month. If I'm riding some sort of endurance event, I want to know that (regardless of adrenaline or fatigue or dehydration) I'm working at my "ride all day" effort.

I don't NEED anything better than the Stages. It does all those things just great. And I think I'm pretty typical of a my type of recreational rider.

In other sports that I do far more seriously and for which I do compete and I do hire a coach, I buy the very best I can afford.

I don't know why Stages can't build a track PM.

timothyw

DC Rainmaker is a lot more measured in his support of left-side only power meters in his more recent 2017 guide:

Would I buy it: This is a much more complex question. Technically speaking it’s a well-made unit that accurately measures the left side. From a pricing standpoint it’s tough to recommend the left-only approach with other options in the same price ballpark that fully capture all power. Further, as I’ve collected a tremendous amount of power meter data over the past year with 3-5 power meters concurrently, I’ve started to understand my specific personal left/right balance biases. For most of my riding, there’d be no major issue with Stages. However for longer or higher intensity rides where I might fatigue more, I see some inaccuracies on Stages due to my personal leg differences. You might be the same, or you might be perfectly even. I don’t know.

I know it’s easy to point at Team Sky and simply say “It’s good enough for Froome”, but the reality is we’re talking about sponsored athletes and teams. In the case of Team Sky, for some riders that are/were seeing imbalance issues with Stages compared to SRM they simply have gone with a ‘known percentage offset’ for wattage goals. This is a bit of a throwing the baby out with the bathwater approach though, that numerous folks have proven isn’t terribly accurate. Which isn’t to take away from Team Sky and Stages, more power to them, but rather my point is that it’s not a one-size fits all implementation.

(Yes, this isn’t just relevant to Stages, but all left-only power meters. It’s just that I wrote the text here first, since it’s the first left-only power meter in the list.)

meanredspider

I don't know DCR's specific issues L-R but as he indicates, you can allow for that if you only use Stages. For most of us recreational riders, it really doesn't matter. If, like Grill, you have loads of (different) PMs then accuracy becomes far more important. I have one that I use for everything- it isn't important.

slowbike

His conclusion is that the Stages PM works fine - in that it consitantly records your left leg power. Given the limitation that your left leg power isn't nescersarily 1/2 your total power consistantly is a limitation - one to be aware of and certainly to be considered when looking at purchasing a PM.

Quite simply - the single side power meters have their place and their limitations, with some advantages - whether that sits with the riders needs or not is up to the individual.

Just to draw back on one of MRS's points ...

I can take my stages PM and fit it to all the road going bikes in my garage - or I could take it on holiday and fit it to a hirebike that uses the same pretty much standard Shimano crank - for me, that's a big plus - and outweighs any of the onesided issues that have been raised.

Grill

Slowbike wrote:

I can take my stages PM and fit it to all the road going bikes in my garage - or I could take it on holiday and fit it to a hirebike that uses the same pretty much standard Shimano crank - for me, that's a big plus - and outweighs any of the onesided issues that have been raised.

You could swap a Rotor 3d 24 P2M between your bikes just as easily.

@MRS- I get it, data quality isn't a big deal to you, but that doesn't mean that A) it isn't a big deal to others and it's a good product (although I get that no one likes to hear that something they've spent money on is crap).

birdie23

Grill wrote:

Slowbike wrote:

I can take my stages PM and fit it to all the road going bikes in my garage - or I could take it on holiday and fit it to a hirebike that uses the same pretty much standard Shimano crank - for me, that's a big plus - and outweighs any of the onesided issues that have been raised.

You could swap a Rotor 3d 24 P2M between your bikes just as easily.

@MRS- I get it, data quality isn't a big deal to you, but that doesn't mean that A) it isn't a big deal to others and it's a good product (although I get that no one likes to hear that something they've spent money on is crap).

But it is a good product, it accurately measures your power output on your left leg. Exactly what it is supposed to do. Just because it doesn't do what you want and you don't like it, doesn't mean it's a bad product. It also sounds like you have issues with your unit that most other people don't have.

Grill

birdie23 wrote:

Grill wrote:

Slowbike wrote:

I can take my stages PM and fit it to all the road going bikes in my garage - or I could take it on holiday and fit it to a hirebike that uses the same pretty much standard Shimano crank - for me, that's a big plus - and outweighs any of the onesided issues that have been raised.

You could swap a Rotor 3d 24 P2M between your bikes just as easily.

@MRS- I get it, data quality isn't a big deal to you, but that doesn't mean that A) it isn't a big deal to others and it's a good product (although I get that no one likes to hear that something they've spent money on is crap).

But it is a good product, it accurately measures your power output on your left leg. Exactly what it is supposed to do. Just because it doesn't do what you want and you don't like it, doesn't mean it's a bad product. It also sounds like you have issues with your unit that most other people don't have.

Dude, loads of people have had issues. I get spikes, dropouts, and battery drain. You're more than welcome to swing from Stages' proverbial sack if it makes you feel good, but it's not like they're going to send you a free one for being their number one fanboy.

meanredspider

Grill wrote:

Slowbike wrote:

I can take my stages PM and fit it to all the road going bikes in my garage - or I could take it on holiday and fit it to a hirebike that uses the same pretty much standard Shimano crank - for me, that's a big plus - and outweighs any of the onesided issues that have been raised.

You could swap a Rotor 3d 24 P2M between your bikes just as easily.

@MRS- I get it, data quality isn't a big deal to you, but that doesn't mean that A) it isn't a big deal to others and it's a good product (although I get that no one likes to hear that something they've spent money on is crap).

Just to be clear, Grill, I didn't claim (quite the opposite) that I'd be happy using a Stages for competitive track cycling. The whole Stages thing came up because you suggested (maybe flippantly, maybe not) that the reason why people don't use PT hubs is because they want shiny carbon wheels. Flippant or not, it's just plain wrong.

I looked at PT hubs well before I got the Stages (and looked at P2M and Vector - in fact I ordered both and cancelled both orders) - all those 3 alternatives presented me with compromises I didn't need to make (the P2M would mean changing chainrings - which I'm not sure was even possible compact/double - between bikes). There isn't a one-size-fits-all PM out there. I believe Stages comes closest to it in form factor but it comes with some other compromises that I can live with.

I read somewhere that Stages had outsold the rest of the PM market put together (at some point) so it seems others agree. In the same way that I wouldn't argue Starbucks makes great coffee, Stages is clearly incredibly successful and meets a need. As I've said before, if I was a serious amateur competitor, I'd get something better. If I had better hearing, I'd get a better stereo. If I was a better guitar player, I'd get a better guitar.

Which brings me to my final point. In most aspects of cycling, if you rock up with pro-level equipment as a weekend warrior, you get derision. Except with PMs it's the reverse - if you don't buy a pro-level system you're met with derision. Cycling is a funny old world.

Grill

meanredspider wrote:

There isn't a one-size-fits-all PM out there. I believe Stages comes closest to it in form factor but it comes with some other compromises that I can live with.

Stages relies on the having the same chainset (or at least brand) on all your bikes as well as the same crank length. A PT wheel at worst needs the brakes adjusted (as Campag 11spd works with Shimano/SRAM). Even then, PowerTap pedals are probably the most interchangeable option.

If the compromise you were happy with was data quality then you may as well have bought a PowerPod.

At the end of the day you can buy and use whatever makes you happy. What I take issue with is recommending an inferior product simply because it works for you (which plays right back into my OP that people who buy such products don't actually care about power for anything more than bragging rights).

meanredspider

Grill wrote:

meanredspider wrote:

There isn't a one-size-fits-all PM out there. I believe Stages comes closest to it in form factor but it comes with some other compromises that I can live with.

Stages relies on the having the same chainset (or at least brand) on all your bikes as well as the same crank length. A PT wheel at worst needs the brakes adjusted (as Campag 11spd works with Shimano/SRAM). Even then, PowerTap pedals are probably the most interchangeable option.

If the compromise you were happy with was data quality then you may as well have bought a PowerPod.

At the end of the day you can buy and use whatever makes you happy. What I take issue with is recommending an inferior product simply because it works for you (which plays right back into my OP that people who buy such products don't actually care about power for anything more than bragging rights).

A PT is interchangeable, as I said right at the outset, IF you run QR rim-braked wheels of similar widths with equal hub spacing. Even then, there's a good chance you don't run the same cassettes on your bikes. I don't run any of those similarities on ANY of my bikes - I kinda see it's pointless to have two bikes that similar.

For pedals to work you need to run the same pedals on your bikes and cleats on all your shoes. Again, I don't. The Renegade runs SPD because it's an off-road bike. I'd imagine this is the same for CXers.

What is easy to do is to run Shimano Hollowtech on all bikes (CX/Adventure/TT/Road) which I do without any real compromise. And it doesn't matter what grade of Shimano each bike has.

I've not recommended Stages I have just disagreed with your conjecture that it's because I want shiny carbon wheels - which is borlicks. It's also borlicks that I run a PM for bragging rights.

I first bought a PM because I was doing "Alpe D'HuZes" (6x up the Alpe in a day). I was training in North Holland. I wanted to know what power I could put out all day so I could pace myself to ride up the Alpe all day. It worked perfectly and I did The Six. And we and my 5 Dutch colleagues raised €40,000 for cancer research and care (including donations from some lovely people on here)

So the Stages doesn't work for you and you're bitter about that. Frankly it was a pretty daft purchase for your use. You can deflect your frustration by saying that people buy them for "bragging rights" or to have "shiny carbon wheels" which is utter nonsense. It does exactly what I need it for and I've seen absolutely nothing to suggest that the data it produces for what I need is anything but brilliant - and I have many thousands of kilometres of data to demonstrate that.

Grill

You only have a single data point (your Stages). It sounds as if it's been consistent for you, which is great, but that doesn't mean the data is correct (bad data, even if it's consistent, is still bad). What happens when you change PMs? Let's assume your Stages is accurate in its left leg reading, but you have asymmetry. If you went to a crank based system you might see a 10% difference in readings, but how would you A) know and know how much to adjust the slope?

So you don't have a Stages because of the need for pretty wheels. Congrats. All that means is that you don't fit Stages' target demographic.

BTW- Raising money for cancer has zero relevance to the discussion at hand.

meanredspider

Grill wrote:

You only have a single data point (your Stages). It sounds as if it's been consistent for you, which is great, but that doesn't mean the data is correct (bad data, even if it's consistent, is still bad). What happens when you change PMs? Let's assume your Stages is accurate in its left leg reading, but you have asymmetry. If you went to a crank based system you might see a 10% difference in readings, but how would you A) know and know how much to adjust the slope?

So you don't have a Stages because of the need for pretty wheels. Congrats. All that means is that you don't fit Stages' target demographic.

BTW- Raising money for cancer has zero relevance to the discussion at hand.

I don't have a single point of data. I have run it against my Tacx Neo with which it agrees very well (I also ran it against the Neo's predecessor, the Fortius - but that device was sensitive to tyre pressure and calibration). As power meters go, the Neo literally generates power directly and has doesn't need to worry about weight). But let's not let that bit of information get in the way. ETA Tacx claim the Neo to be accurate (tested independently) to +/- 1% - how does that compare to each of your PMs? But let's not let this further bit of info get in the way.... [end edit]

So I swap power meters? So what? It'll take me a few rides to see whether the power curve I'm generating matches the power curve from the Stages (assuming there's no time break between the two. If there is a significant time break, so what - I just build a new power curve as a baseline). If the two curves are different (the Neo suggests they won't be by much) , I'll just adjust my targets accordingly. It's really no big deal. I'm a keen recreational cyclist not a pro.

I know quite a few Stages users - not one of them is "shiny wheels" rider (there's not many of them in the Highlands) but you stick to your prejudices. You're a Stages user too after all.

As for the cancer thing - I think it does. I spent a few hundred quid of my own money on a PM to help raise tens of thousands for others. That's as far away from "shiny wheels" and "bragging rights" (which after all is pretty much only what amateur racing is about) as you can get. And I always take the opportunity to thank those folk on here for donating (some might even still have their epilators ). I like the idea that you can tell me that shiny wheels and bragging rights are relevant to PMs but raising money for cancer isn't. I think we're done. I'll go and make dinner for my daughter who has acute leukaemia.

Grill

Wow dude, you're going to actually use your daughter who has leukaemia in order to make your case? I'm out dude, that's just too f*cked up for me.

meanredspider

Grill wrote:

Wow dude, you're going to actually use your daughter who has leukaemia in order to make your case? I'm out dude, that's just too f*cked up for me.

Job done. I think it's f*cked up that you think raising money to help people with cancer isn't a valid reason to buy a PM. Enjoy your racing "bragging rights" with your multiple PMs to tell yourself and your buddies just how "good" you are.... :roll:

Grill

meanredspider wrote:

Grill wrote:

Wow dude, you're going to actually use your daughter who has leukaemia in order to make your case? I'm out dude, that's just too f*cked up for me.

Job done. I think it's f*cked up that you think raising money to help people with cancer isn't a valid reason to buy a PM. Enjoy your racing "bragging rights" with your multiple PMs to tell yourself and your buddies just how "good" you are.... :roll:

No, I said that raising money for cancer, or any charity for that matter, does not make Stages good. All you've done is throw out straw man arguments that have nothing to do with my original point. Kudos for drawing me in and wasting my time.

meanredspider

Grill wrote:

meanredspider wrote:

Grill wrote:

Wow dude, you're going to actually use your daughter who has leukaemia in order to make your case? I'm out dude, that's just too f*cked up for me.

Job done. I think it's f*cked up that you think raising money to help people with cancer isn't a valid reason to buy a PM. Enjoy your racing "bragging rights" with your multiple PMs to tell yourself and your buddies just how "good" you are.... :roll:

No, I said that raising money for cancer, or any charity for that matter, does not make Stages good. All you've done is throw out straw man arguments that have nothing to do with my original point. Kudos for drawing me in and wasting my time.

You're unbelievable. You've started with nonsense trolling about shiny wheels which I've addressed and you've just dodged about changing your position. And it's you that's bought the Stages for its worst possible application! Then, when I tell you why this Stages user bought a Stages (and, no, it wasn't shiny wheels or bragging rights (rich coming from the guy with so many PMs)) you claim that it's not relevant!! It's my time you've wasted with your shiny wheel/PT nonsense.

cycleclinic

Owning two garmin vector pm one single sided, one double i know there is 8% inbalance in my legs. That varies as well a bit.

I would not buy a single sided meter again and i would stay away from stages as they get lots of issues. The cheapest reliable is the powertap hub.

The point of power meters is give reliable accurate data you can use in training. The cheap pm i feel may just be to provide numbers to make you feel better. Effective training can be done without a PM.

Grill

You ever laced a G3 to a Hed Belgium Plus? Thinking about making a pretty wheel...

myideal

courtmed wrote:

Taking this further, how about this single sided crank arm one for £250?

http://road.cc/content/tech-news/221643 ... -%C2%A3250

Will definitely be looking out for a DC Rainmaker review on that one!

Looks interesting and affordable.

I wonder how long we have to wait for someone to test it and see if it is the real deal.

Let's be honest though tech is great as it is bringing more features down to the mass market and overall prices will fall, which everyone benefits from.

OfficerDigby

Grill wrote:

All these cheap power meters come out and they're just awful. If people really cared about power on a budget then they'd buy a PowerTap wheel, but it doesn't happen because it's all about the look (i.e. carbon wheels).

Cheap Power meters is a POTENTIALLY MASSIVE market is the reason!

The masses still waiting for that product I reckon.

Stages could easy drop 50-60% price and still make a profit on masses of products, if there was better competition.

Grill

OfficerDigby wrote:

Grill wrote:

All these cheap power meters come out and they're just awful. If people really cared about power on a budget then they'd buy a PowerTap wheel, but it doesn't happen because it's all about the look (i.e. carbon wheels).

Cheap Power meters is a POTENTIALLY MASSIVE market is the reason!

The masses still waiting for that product I reckon.

Stages could easy drop 50-60% price and still make a profit on masses of products, if there was better competition.

Agreed, and the competition in the midrange has given us SRM level performance at near Stages prices (P2M and Quarq).

birdie23

Grill wrote:

Dude, loads of people have had issues. I get spikes, dropouts, and battery drain. You're more than welcome to swing from Stages' proverbial sack if it makes you feel good, but it's not like they're going to send you a free one for being their number one fanboy.

DUDE! Loads of people haven't had issues. The fact you believe I want to "swing from Stages' proverbial sack" says a lot about your issues with them.

Don't need them to send me a free one as my life doesn't revolve around knowing how much power I'm putting out, I'm too busy looking at the scenery.

Grill

birdie23 wrote:

Grill wrote:

Dude, loads of people have had issues. I get spikes, dropouts, and battery drain. You're more than welcome to swing from Stages' proverbial sack if it makes you feel good, but it's not like they're going to send you a free one for being their number one fanboy.

DUDE! Loads of people haven't had issues. The fact you believe I want to "swing from Stages' proverbial sack" says a lot about your issues with them.

Don't need them to send me a free one as my life doesn't revolve around knowing how much power I'm putting out, I'm too busy looking at the scenery.

Then why have a power meter at all? I certainly don't use them when I'm cycling for fun.

birdie23

Grill wrote:

Then why have a power meter at all? I certainly don't use them when I'm cycling for fun.

I don't have a power meter and never said that I did...

slowbike

thecycleclinic wrote:

The point of power meters is give reliable accurate data you can use in training. The cheap pm i feel may just be to provide numbers to make you feel better. Effective training can be done without a PM.

Actually - just a clarification - it doesn't matter if your PM records in buttons rather than watts ... it's the repeatbility that matters.

Yes, if you're really bothered about your power then you should at least be aware of your leg balance - or get a PM that records both sides - for most, who like to dabble in Power - it doesn't matter.

As for bragging rights @Grill - I don't have shiny or matt carbon wheels - but I do have a stages PM - where do I get my (free) carbon wheels please?

Grill

birdie23 wrote:

Grill wrote:

Then why have a power meter at all? I certainly don't use them when I'm cycling for fun.

I don't have a power meter and never said that I did...

So you simply decided to weigh in that Stages was a good product with no real knowledge of it or PMs in general? Seems legit.

meanredspider

WTF is it with PMs that gets a certain section of the cycling community all hot and bothered? It's like a little clique that doesn't want the hoi polloi encroaching on "their" tech. It's very sweet.

slowbike

meanredspider wrote:

WTF is it with PMs that gets a certain section of the cycling community all hot and bothered? It's like a little clique that doesn't want the hoi polloi encroaching on "their" tech. It's very sweet.

Shhh ... don't tell him I've got Specialized bikes ... apparently they're crap too ...

meanredspider

There are a load of reasons to buy a PM that are as entirely legit as pretty much any bit of cycling gear. Even if you don't need to know instantaneous power, having a pretty accurate idea of energy consumption is helpful - after all, the various apps are utterly hopeless at guesstimating; Garmin notorious and Strava swings from wildly overestimating if I'm on the Renegade to wildly underestimating if I'm on the Foil (aero really is NOT that good). If you're cycling to help manage weight, being accurate makes a helpful difference.

Then there's Zwift and that whole gamification of indoor cycling.

And then there's simple motivation. When you're ploughing demoralisingly into a brutal headwind at barely over 15kmh for 50k, it's good to look down and still see that you're putting out your normal power - because it doesn't feel like it. Been there often.