New Product: Stages Cycling Power Meter

Gear

Among the most talked about products at last fall’s Interbike tradeshow — the Stages Cycling Power Meter — is slated to start shipping to shops and consumers this week. If it can deliver on it’s significant promise, it could mark a huge sea change in the power meter market, substantially lowering the price and weight associated with strain gage-based power measuring systems.

Last week, the Boulder, Colorado-based company gathered about a dozen members of the cycling media to conduct initial test rides and go over final thoughts and figures relating to the new product. RoadBikeReview.com was on hand. Here are the highlights of what we learned.

What it is
In a nutshell, it’s a power measuring device manufactured in Colorado that’s affixed to the inside of a bike’s non-drive side crank arm, and uses strain gages to determine power output by measuring deflection (aka extremely subtle microscopic bending) of said crank under load. Each strain gage is specifically calibrated to the crank it’s mounted on.

The unit takes 64 discrete measures per second, which is far more than necessary for road riding, but could have interesting applications in the track, BMX and even downhill mountain biking world where rapid acceleration is key to success.

All that information is then doubled to account for the fact that it’s measuring just one leg, then transmitted to the receiving device of your choice (Garmin head unit, iPhone, etc.) via ANT+ or Bluetooth technology. There’s also an inboard accelerometer to measure speed and cadence.

It should be noted that Stages does not sell any of these recipient devices, just the non-drive side cranks with device affixed, or full cranksets with device. Also, the system only works with alloy cranks, which bend at a consistent rate, versus carbon with its mix of materials that do not bend uniformly.

That’s no problem for Shimano users who can choose from nine different cranks, including Dura-Ace 9000 and Saint. But SRAM Red or Force aficionados will have to drop down to Rival. This was the case with the RoadBikeReview.com test set-up. We had the SRAM Red 50×34 carbon compact set-up removed from our road bike, and replaced with a SRAM Rival set-up including the new power meter and a BB30 adapter made by Wheels Manufacturing. The net effect was a 154-gram weight penalty (from 624 grams to 778 grams).

Stages says it is currently working on a better BB30 solution, which will utilize Cannondale’s various BB30 cranks. But that wont be available until later in the spring at the earliest. You can see the full line-up of current offerings, including available lengths and colors here.

FSA and Campagnolo are not among the choices and from what we heard during the two-day press event, it doesn’t sound like that will change anytime soon.

According to Stages marketing man Matt Pacocha, the unit works with “about 90 percent of the road bike frames on the market. It just depends on the location of the rear brake. It can be an issue with some lower priced time trial bikes, which use a full-sized caliper on the chainstay.”

Stages does not retrofit its product on previously purchased crank arms, so don’t bother asking if you can stop by Boulder HQ with your old crank in tow. The answer is, no.

The unit is powered by a CR2032 battery, which will cost you about a dollar at the grocery store. Run time is claimed to be 200 hours, with accuracy pegged at +/- 2% when measured at 100 watts and 90rpm. Occasional free firmware updates will be delivered via Bluetooth by way of the Stages Cycling Utility App, which will be available soon.

The Stages cycling power meter also includes a built-in thermometer, which feeds info into the main calculation so temperature change does not effect accuracy.

Some may question the accuracy of measuring just one leg. But Stages did its best to dismiss this concern, bringing in well-regarded cycling coach Neal Henderson, who’s the sports science manager at the Boulder Center for Sports Medicine. Serving as an expert witness of sorts, Henderson said he rarely sees significant output differences between legs, and it’s usually with patients who have had a knee or hip replacement, or some other significant body change.

Henderson also said he’d been doing some testing with the Stages Power meter and liked what he saw, writing on Twitter, “I’m impressed with ‪@stagescycling so far. Simple use, very light weight, consistent data, & very close to other validated PMs.” You can read more of what Coach Neal had to say on his Twitter stream and see links to his various power files.

Price & Weight
Prices on the Stages Cycling power meter start at $700 (SRAM Rival, SRAM X9) and climb to $900 for Shimano Dura-Ace, XTR and Saint. The Cannondale Hollowgram models will run $50 to $100 more than Dura-Ace when they become available in the spring.

The power meter can be purchased via the Stages Cycling website, or at select independent bike shops. Purchase price also includes a 1-month premium subscription to both TrainingPeaks and Strava, roughly a $26 value.

By comparison, the least expensive PowerTap model runs $899, but that’s just for the hub. You still need to build up a wheel, which you will then be locked into if you want to ride/train/race with power. SRM and Quarq don’t restrict wheel choice, but the least expensive model is the recently-introduced Quarq RIKEN, which retails for about $1600. Prices of SRM and Quarq quickly rise into the $2000 range.

We didn’t actually get a chance to weigh one of the Stages units ourselves, but claimed weight is “under 20 grams” and senior VP Pat Warner said that most units are closer to 14 grams. The weight hit for PowerTap models is in the 100-gram range, while spider-based systems typically add around 30 grams.

The variance in weight for the Stages system is due to the difference in protective housing shape from one crank model to the next. This housing is bonded onto the crank using a proprietary method that Stages claims does no damage to the crank itself, and creates a bond so strong that the two pieces effectively become one. That means it’s totally waterproof, though Stages warns that it should not be directly sprayed with a pressure washer so cross racers need to be careful.

Each power meter comes with a one year warranty, and a longer warranty (think Apple Care) can be purchased for $105 to $135 depending on the model you choose. This could be a wise choice for mountain bikers and cyclocross racers, who run a much greater risk of suffering a direct-impact rock strike or crashing.

New Product: Stages Cycling Power Meter Gallery
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Stages Cycling Power Meter Press Camp Test Ride

Photo by: TomK Photo
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Stages Cycling Power Meter Press Camp Test Ride

Photo by: TomK Photo
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Stages Cycling Power Meter Press Camp Test Ride

Photo by: TomK Photo
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Stages Cycling Power Meter Press Camp Test Ride

Photo by: TomK Photo
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Stages Cycling Power Meter Press Camp

Photo by: TomK Photo
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Stages Cycling Power Meter Press Camp

Photo by: TomK Photo
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Stages Cycling Power Meter Press Camp

Photo by: TomK Photo
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Stages Cycling Power Meter Press Camp

Photo by: TomK Photo
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Product is about to fly off these shelves

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Power Meters Ready to Ship

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Lots of Left Side Crank Arms

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Examining other's product

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Evidence of Schwinn heritage

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Testing in process

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The interface is seamless with most frame designs

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StagesPower will work with multiple devices

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StagesPower on an Ultegra crank

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Road Crank Options

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Mountain Crank Options

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Clearance gets tighter on MTBs

About the author: Jason Sumner

An avid cyclist, Jason Sumner has been writing about two-wheeled pursuits of all kinds since 1999. He’s covered the Tour de France, the Olympic Games, and dozens of other international cycling events. He also likes to throw himself into the fray, penning first-person accounts of cycling adventures in British Columbia, Belgium, Brazil, Costa Rica, France, and Peru among many others. Sumner, who joined the RoadBikeReview.com / Mtbr.com staff in January, 2013, has also done extensive gear testing and edited a book on cycling tips. When not writing or riding, the native Coloradoan can be found enjoying the great outdoors with his wife Lisa.


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  • Sebastian Zdyb says:

    I’m very happy to see more power meter developers on the market. Did anyone rode the system with another power meter like powertap or quarq and can post results?
    At that price this looks like a winner and great product. Do you need to zero out before each ride?

  • Jon Mags says:

    When do we expect to have side by side comparisons with powertap, SRM and Quarq? I’d like to see how this stacks up… $700 is way cheap for a PM compared to the options available now!

  • james conley says:

    how would this be most useful, as a comparison to others’ level
    of output, as a comp. to previous outputs to monitor improvements,
    as a means of monitoring outputs during a given ride to guard against
    overexertion/fatigue? I guess what I’m saying/asking, is that the
    article mentions how read-outs on Stages Cycling powermeter are
    arrived at, but not how they are best used. Its out of my range anyway, for
    the time being, so no worries!

  • James says:

    Gosh, how did Eddy Merckx get so good without a power meter?

    • geekonabike says:

      Good point. You know the UCI can ban radios, How would team Sky get through the neutral zone w/out there power meters?

  • JP says:

    Why was the iBike Newton not mentioned in the comparison? It’s very reliable and consistent and can be used on any bike with any crank and any set of wheels. You can move it from bike to bike, with only an additional mount that cost $39. Again no wheel changes, no switching of cranks or crank arms and it cost less than or equal to the new Stages PM. Also the iBike has a firmware upgrade that will pick up A.N.T. devices that can be used with SRM,Quarq and PowerTap and now Stages if so desired. The iBike also has comparisons with all the PM’s mentioned above except for the new Stages PM. I’m just saying.

  • Will says:

    I purchased stages power crank just on the non drive side on June 7, 2014. For Shimano 105. It has worked great. Had a problem when battery had to be changed due to not making contact. Excellent support from stages mailed me different cover. The power meter has improved power 20 sec by 58%, 1 min by 52%, 5 min by 37%, 20 min by 20% and 60 min by 17% in just 3 months, even though I have trained by power on computrainer for 4 years. It was easy to install and get working with cyclecomputer and strava app on iphone.

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