Stages Power Meter – Final Thoughts

It isn’t often that we get to ride the same gear as Team Sky. Sure, we get some pretty amazing products in to test, but there’s a fairly short list of shared components between Chris Froome’s bike and ours. In fact, it is exactly two items long: Oakley Radarlocks and the Stages Cycling Power Meter. After spending quite a bit of time with the latter, we can absolutely understand why Sky chose Stages to provide the data Froome spends so much time staring at – it’s just that good.


Stages’ solution has a lot going for it, especially when you consider the professional peloton, where weight is the enemy – it is compact, easily replaceable, accurate, has a small footprint, and is incredibly lightweight. A PowerTap’s additional weight, as a comparison, is around 60g heavier than a standard Zipp hub. In contrast, Stage’s strain gauge adds just 20g—one-third the weight of a PowerTap—to the crank arm. Sure, we’re not talking about kilos, here, but with rotational weight, every gram counts. After all, the highest compliment to a component looking to add functionality but keep the weight down is invisibility. Besides the Garmin telling us exactly how far we are from Froome’s power output we were, we simply couldn’t tell it was there. Maybe that’s why we’re triathletes and not Tour GC riders. Ah, well.


By far, the most common question we’ve received from readers has been about the left-only power data, and whether it would prove problematic; we’re happy to report that the answer is a resounding, “Nope.” Stages, by virtue of replacing the non-drive side crank arm only, can only give power data for the left-leg portion of the pedal stroke. Yes, this gives, in theory, an “incomplete” picture of your power, but that’s not really what power is for. You don’t need to know your output down to the last fraction of a watt; what you need is consistent power readings in order to design workouts, plan race strategies, and realize when you’re pushing yourself too hard, too early. Power data is informative data, not granular data. To put it another way – it’s feedback about what you’re doing, instead of deep-dive analysis on the fly. For that, you want trends and models… both of which are only possible by examining your data, ensuring it’s consistency, and doing so over a long time span.

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This means that the consistency of what your power meter gives back is far more important than the number on your Garmin itself. The Stages meter is accurate to +/- 2%, which is plenty for everything we’ve described above. We could look at our power at a glance and know that we were burning a match in the sprint zone on Sunday, but only by understanding our “normal” numbers from Stages, and being able to trust that we were getting good data. We were, and while we may have won the sprint, we were riding back of pack by the end. Lesson learned: Stages may know more about our legs than we do.


Being one step closer to Froome’s kit has taught us a lot of things, chief among them that power data—for an athlete who wants to improve—is absolutely indispensable. Today, our legs are stronger, go farther, and feel less fatigue, all because we can tailor our workouts and understand what we were doing on a level that was impossible by riding on heartrate or feel alone. That’s the real power of power data. For $7-900, we’d be hard-pressed to find a better performance enhancement tool, short of hiring a personal coach.

6 responses to “Stages Power Meter – Final Thoughts

  1. Regarding rotational weight, I think it is instructive to quantify how big of a deal that is. Assume you added 500 grams to the weight of a cyclists wheels, all of it at the rim. Then said cyclist does an all out 10 second sprint @ 1,500 watts for 10 seconds. That 500 grams of mass will ‘cost’ approximately 5 watts. If that mass was on the frame instead, it would cost 3.5 watts giving a rotational bonus penalty of just 1.5 watts. So yes, rotational weight is worse, but only a bit in the most extreme cases. In the case of a powertap where the mass is located at the hub, the extra penalty of rotational mass works out to zero point zero. Pretty close to the same result with the stages mass since it isn’t very far from the center of rotation either.

    • Jack has the right of it: the differential in weight as it affects your performances from adding either a PowerTap or a Stages meter is functionally zero. Our note that the Stages was 40g lighter than the PowerTap where OEM parts are concerned was meant as a compliment to Stages for miniaturization and not as a dig to CycleOps or advocating one over the other. Rather, that both do the job well with a minimum of fuss. Our apologies if this did not come through correctly.

      I did the math on the rotational weight of both tonight and the difference between the two is functionally a rounding error when we talk about watts required (even if we factor in drive train losses). If you want to ride with power, pick whichever one you like and be content with the purchase

  2. Some decent sized misconceptions and misunderstandings conveyed in this item, with zero critical analysis of the product.

    If that’s all you think power is about (hint, it’s not, not by a long shot), then perhaps it’s good thing these are your final thoughts.

  3. Pingback: 6-22-2014 WiR | AeroGeeks·

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