Garmin Fenix 3 drops data from Stages power meter

I’ve been ignoring this problem for a while, hoping that it would be fixed in a firmware update, but it persists, and I finally got aggravated enough with it to write this post (and to engage Garmin support). The problem is simple: my Garmin Fenix 3 triathlon watch will not reliably record data from the Stages power meter I have on my bike.

A quick digression: there are two major standards for wireless exercise sensor connectivity, Bluetooth Low Energy (aka BLE and Bluetooth 4.0) and ANT+. Some devices support one or the other, and some devices support both. For example, my heart rate monitor (the excellent Scosche Rhythm+) simultaneously transmits both ANT+ and BLE signals, but my Wahoo speed/cadence sensor is ANT-only. When I ride, I usually use two devices: my old iPhone 4 on the handlebars, in a Wahoo case that has a built-in ANT+ adapter, plus my Fenix 3. The iPhone is too old to use BLE, and turning on BLE on the Fenix 3 dramatically drops its battery life, so I’m using ANT for all the sensor data. Having two devices means that sometimes I forget to start or stop one device or the other at various points, so I often have mismatched data between the two.

A picture will illustrate the problem most clearly. When I use the Fenix 3, I end up with ride data that looks like this:

Bad power data is bad

As you can see, the power graph has a few spikes with lots of flats– and an average power of only 23W. (I’ll get to why the average is important in a minute). By contrast, here’s what the ride looked like when captured with the Strava app on my iPhone 4. Note that the power data much more closely tracks the speed, cadence, and HR data.

That's more like it

So why is this important? First of all, as a techie, it annoys me when two things that are supposed to work together won’t. More importantly, I actually use the power data from these rides in two ways. While I’m on the bike, I use it to gauge and adjust my level of effort. For example, yesterday’s ride was pretty windy, so I tried to hold a steady 190-210W while riding into the wind, keeping my level of effort constant and accepting whatever speed that gave me. After a ride, my coach and I use the power data to plan my recovery time and to identify areas where I need more practice (e.g. climbing hills). Having inaccurate or dirty data makes both of these uses impossible.

The Stages power meter support FAQ suggests moving the watch around, but I haven’t tried that yet. My troubleshooting efforts so far have been limited to changing the battery in the Stages and making sure the Stages and Fenix both have the latest firmware. I’ll see what Garmin support has to say. Hopefully they have a magic fix; I have a very early-model Fenix 3 so maybe they’ve made some improvements since launch. Until then, I’ll keep recording each ride twice and keeping the cleanest data.

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15 Comments

Filed under FAIL, Fitness, General Tech Stuff

15 responses to “Garmin Fenix 3 drops data from Stages power meter

  1. Martin

    Hi Paul. Any update on this issue ? I use a Stages power meter and considers buying the Fenix 3 HR when it is available. Thanks

    • robichaux

      Garmin blames Stages. Stages blames Garmin. Some research on Slowtwitch shows numerous complaints about the combination of Stages PMs with the Fenix and 920xt line. The best explanation I’ve seen is that the Stages transmitter is rotating, and something about the Garmin antenna design doesn’t handle it well. Workarounds include putting the watch on your aero bars or stem, which I don’t especially want to do. Garmin has offered me a warranty replacement, which I appreciate; I guess I’ll take them up on it and see if that fixes the issue, but I’m not optimistic.

  2. Justin

    Paul, I’m having a similar issue with the combination of Stages power meter and Garmin Fenix 3. I have the Fenix mounted on the aerobars of my tri bike, but every 5 seconds or so, the ant+ signal drops out-no cadence or power. Sometimes this lasts a micro-second, but sometimes it takes a couple of seconds before the signal comes back. Funny thing is that I have my iPhone 6 paired via Bluetooth to the Stages power meter, and can see cadence and power via the app. The Bluetooth signal never drops out, even when my Fenix 3 isn’t showing anything from the ant+ signal. Stages has a list of fixes on their website here: http://support.stagescycling.com/support/solutions/articles/1000137893-i-m-experiencing-drop-outs-in-my-power-readings-

    I’ve accomplished the battery replacement and ensuring that the door and its o-ring are properly installed to no avail. I’m going to continue down their protocol, but moving the Fenix 3 to a place where I can’t see it while riding makes it pretty useless to me. This is frustrating as the purpose of a power meter is to provide consistent data so the rider can analyze and train accordingly. If the data is faulty and inconsistent, it serves no purpose other than to be an expensive crank arm.

    My best guess is that the problem is in the sending of the signal, the receiving of the signal, or both. Either way, it’s a convenient excuse for the companies to blame each other’s products, although I hear that Stages has an excellent customer service group. Keep us in the loop if you find a fix, and I’ll do the same. As the Fenix 3 is pretty new, there isn’t much about this issue written up. Good luck!

    • robichaux

      Like you, Justin, I’ve been through the suggested troubleshooting steps that Stages proposes and they have done no good– I have the latest door hardware and a fresh battery, but still no go. I think I’m going to bite the bullet and buy a bike computer, but I wish either Stages or Garmin would figure out what the problem is and FIX it.

  3. temason

    I have the same issue, when I log data on both my Fenix 3HR and Edge 1000 the Edge data is fine but Fenix power and cadence is so intermittent it’s useless. I have a new Stages Carbon crank (FSA SL-K) mower meter.

  4. I have the same issue, but not as procounced as you. The recordings of my Edge 500/810 are perfect, but the Fenix seems to lose connection from time to time showing 0 cadence. Especially when riding out of the saddle.

    • robichaux

      I’m still having the same problem; in my tests I’ve found that strapping the watch across the top tube eliminates the problem, but then a) I can’t see the watch and b) it will take me extra time in T1/T2 to move the watch from my arm to the tube. I ordered a Wahoo ELEMNT and will just use it instead.

      • temason

        I’ve found rotating the fenix to the imside of my wrist on my left hand gets me pretty reliable data – still get the occasional dropout but so does the edge.

  5. Marcin Jachimek

    Any news guys ? Issue is solved or no ? I want to buy stages powermeter and I want to use them with Fenix3.
    Thx for replay
    Czlowien

    • robichaux

      Still broken. I gave up and bought a Wahoo ELEMNT computer. It records the Stages power flawlessly.

      • Marcin Jachimek

        Thx….
        I am dissapointed…. I found a lot information about this issue but I don’t know if all models of Fenix3 has problems with stages or you need to have bad luck. I want use power meter during competitions and trainings… so it would be great set (fenix & stages) – but only in case when both work correct.

  6. JAV

    I have the same problem…

    Question: what app (shown in this article) are you using to record your data?

  7. xcsnine

    hi paul, any update on this? i’ve got the same issue with my stages pm and my fenix 3 hr.

    thanks!
    nick

    • robichaux

      Sadly, no update– I gave up and use my Wahoo ELEMNT to get power data. It works flawlessly every time, unlike my Fenix3.

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