I think it's a little extreme to say it's totally junk data and is unusable. Maybe I'm leaving huge gobs of power on the table because my training is less than optimal. I simply don't believe that. Should he consider selling it and upgrading sometimes soon, sure? But... front door brag warning here.... i kicked the ass of a lot of folks on the Big Island back in October with far better bikes, wheels, helmets, fancy nutrition, expensive coaches, high end power meters, you name it all over Kona in October. I don't even think I had that great of a build in terms of volume, trained less than the year before and was 5lbs heavier. It didn't matter... until I hit the run at least.

I have the same issue with my Stages. I'm either the most aerodynamic triathlete on the planet for my size, or my left leg is stronger... or a little of both. There's no fixing it. All power meters vary somewhat, so you really need to use threshold power tested on that bike with that power meter and set your zones accordingly. Unless your doing aero testing, the accuracy isn't important. Although there is the issue of variability between L/R balance over time and at varying power levels.

I'm still waiting for a better powermeter to show up on my doorstep. Until then I work around what I have and still consider it far better than heart rate for training, pacing and tracking training load.

Should the OP have bought a Stages? Probably not for the reason above. But he's stuck with it now, so unless he has a deep well of funds, it can be utilized to provide adequate data for training with power. Taking care of "low hanging fruit", doesn't require a high level of precision.

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TrainingBible Coaching
http://www.trainingbible.com

same problem here. stages is notoriously low IMHO. see this thread:
http://forum.slowtwitch.com/...g=bypasskid#p5918541

*I added the underline.* This definitely isn't directed at motoguy, he's a really good resource here and thinks things through.

I want to emphasize precision is way more important than accuracy for training with a power meter. Both would be nice, but only precision (repeatability) is truly important. I think that's what you're saying too. I'm not a Stages user, but I don't think we (As a ST community) really have any reason to believe that Stages meters aren't precise. Any arguments over leg imbalances or measuring one side only are completely irrelevant as long as the Stages keeps measuring the same number for the same output of the left leg across a wide variety of conditions.

No, we kinda do. For most people their balance is going to vary in lots of ways, so stages is not precise. Stages saying 200 watts one day (or even at one time in the ride) will not always be the same 200 watts on another day, because someone's balance may change.

Stages is not useless, but it is not as precise or as accurate as other power meters and I just do not think the price is justified relative to P2M, powertap hubs, or quarqs.

I seriously considered a Stages 2 years ago, as it was the only power meter I could have afforded at the time but it would not fit my bike. I recently got a Quarq. I am quite glad I have 2 sided power meter.

But, I would have been better off now if I had had a Stages power meter back then back then and had 2 years of training with power in today instead of just a few months ;-) Virtually any power meter is better than no power meter, even if some power meters are "better" then other power meters.

I think too many people here get hung up on accuracy such that they obsess over whether they are really putting out 210 watts versus 222 watts at any given moment instead of using whatever tools they actually are capable of acquiring or already have in a sound disciplined manner to get to 300 watts. Start with the proposition that everyone should buy an SRM. Assuming you have to compromise on budget though, Stages is a sound choice if that is what fits your budget.

No, we kinda do. For most people their balance is going to vary in lots of ways, so stages is not precise. Stages saying 200 watts one day (or even at one time in the ride) will not always be the same 200 watts on another day, because someone's balance may change.

Disagree.


Stages is not useless, but it is not as precise or as accurate as other power meters and I just do not think the price is justified relative to P2M, powertap hubs, or quarqs.

Agree.

FWIW, for entertainment purposes I have of late been watching the estimated power balance my Quarq gives me. I do have a power inbalance (assuming the estimate is correct . . .) that does vary with power level but the numbers are quite consistent within a ride and from ride to ride. I favor my right leg at low power and more the lower the power goes but it gets closer to even as I approach FTP power and at higher effort levels it is 50-50 or at worse 49-51. I don't see any significant changes in this from ride to ride.

I know everyone is different but assuming the numbers I am seeing are accurate (and I know they my not be), a one sided power meter would give me different readings then what I see with my Quarq for large parts of any given ride, but it would be more than precise enough to be just as good a training tool for me as my Quarq. I could still hold a steady power in a given zone at low to moderate powers. At high power it would be spot on, but that does not even matter much because at 125%+ of FTP, my power bounces around a bit anyway.

For what it's worth, I was previously using virtual power on TR. I was very consistent with my set up every time to try to get as much precision as possible. Once I got the Stages, my FTP went from 315 to 224. Impossible to say which one was more off, but I simply go with the Stages number these days to keep consistent when out on the road. My ego really liked the 315 much better even if it was "virtual".

I purchase a Stages about a year ago out of a clearance bin for $300 when they discontinued an older dura ace arm. It didn't match my Ultegra crank, but it was completely compatible. A few weeks ago, they replaced it with a new Ultegra arm under warranty due to the well documented early generation battery door issues. For what I paid, I am very happy with it.

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"It's good enough for who it's for" - Grandpa Wayne

I will just have to assume that I am right leg bias as stages tells me they test + or - 2% of the power beam.

I also think my number may not be as high but as long as it is repeatable like some have said it should not matter (I don't pay attention to strava)

The reason I bought one is to be able to have measurable improvement.

I was initially concerned as I thought maybe my stages was bad. Thanks

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Yellowfin Endurance Coaching and Bike Fits
USAT Level 1, USAC Level 3

The bullshit idea that accuracy doesn't matter needs to die. Seems like it is an increasingly common argument since stages came to market. With this argument why do we need power meters that read anything but 1 to 100 with no units.

For the prices we pay for these items they should be precise and accurate. No excuses and apologies and good enoughs.

Especially along with all power meters vary anyways so it doesn't matter. They really don't vary that much I have maybe a 1-2 percent difference between my Quarq and Computrainer which is exactly what I would expect CT is lower. Just because the equipment you're using isn't accurate, doesn't mean you can back into the arguement that it doesn't matter.