Power question

I have a Kickr and am curious what power metric Wahoo is using in the SYSTM app. I have the power smoothing (3 seconds I believe) enabled. My bike has a non-drive side 4iiii power meter connected to my Wahoo roam. I have yet to find any power metric in the roam that is remotely close to the power numbers I see via the Kickr to the app. There are many choices within the element app (for the roam) but all that I have tried are indicating much lower power numbers. I’ve tried 3 seconds power, np, and a few others with no success. Any ideas?

Hi there, and welcome.

The power that the SYSTM displays is shown by the hardware connection we pick during device connection - so when you begin a workout and the device connection pop up is showing (if it is), there are icons for which is being used as a controllable trainer, for straight power reading, for cadence and for HR. And you can choose which one SYSTM uses in its power display.

Same for the Roam - it can read power from any power device you have. In the Roam’s case you can see which power device is connected in the device screen using the left hand side button (well it’s the left hand side button on the Bolt so hoping it’s the same on the Roam)

In summary the app uses which source we choose in device connections. To get that pop up there’s a settings button top right which will open the three settings tabs. Go in to the devices tab and see which one you are already connected to. You can then remove it and use a different one if needed.

I’m not 100% sure I’m fully answering the question here so apols if not - pls shout if so …

Thank you very much! I guess my question is when the Kickr connects to the app is it displaying raw watts or is it something else (maybe nominal power. Watts 3 second ave etc.) Mu thinking is that if I used that that on my roam the power numbers would be similar. Thanks again for all of your information and help, I really appreciate it!

Watts. Possibly smoothed (like 3 sec) depending both on SYSTM’s settings and you sensor’s settings.

Hiya. The default is raw from the kickr.

You have two smoothing options.

  1. One on the Wahoo Fotness app where there’s a toggle for the Kick’s own smoothing feature.
    (I’ll throw in an opinion here that personally I don’t like this much so don’t use it, as it makes it look like I have perfectly even power delivery all the time when I don’t, I prefer seeing my actual data … but it is there as a choice)
  2. In SYSTM itself there is an option to show 3s power - in the settings tab (one of the three tabs i mentioned earlier) there is a power smoothing toggle. I think that changes what’s displayed to a 3s average.

Disclaimer. Only Wahoo/Sufferfest folks will know the precise operation of both of these, or maybe it’s in the various product docs. That’s my understanding of it

I have the same setup as you (4iiii single side + KickR)

I initially tried dual recording on the 4iiii linked to Elemnt and kickr to the Systm app (sufferfest when I did it). Doing this I found 4iiii consistently lower. I’ve never managed to get them REALLY close and it varies depending on how hard an effort I’m doing - I’ve put it down to the 4i being left side and kickr on the cassette/ drive train & it’s likely my left (non dominant leg) is a bit weaker.

I’ve found the best setup to use the kickr app to get the kickr to read the 4iiii power meter via ant+, in theory that would mean consistent power source inside and out. See here for how to setup: https://support.wahoofitness.com/hc/en-us/articles/115000506290-Using-Your-KICKR-and-Power-Meter-With-the-iOS-Wahoo-Fitness-App

Like Sir Martin I’m not a fan of the smoothing in the wahoo app, it’s way too clean. Instead I use the systm version

I’ve also got the same setup (4iiii left side & a KICKR 5th gen) & have done the comparison using my ELEMNT BOLT paired to the 4iiii as a comparison. They come out pretty close. I’ve since installed a dual-sided 4iiii crank PM on my outside bike & know that I have an imbalance where my right leg is stronger by 5%-7%.

I took both .fit files & put them into Excel, & used a 3-median smoothing & the plot below is what I get. The output of the Kickr is already smoothed & I believe the ELEMNT is raw. I also show the % difference which shows it generally about 5% different.

When I look at the values, the 4iiii PM is reading an average of 6.5W low, but I think that difference is pretty clearly explained by my 5%-7% imbalance favoring my right leg.

Ultimately, if you have your ELEMNT running simultaneous while riding the KICKR, your values should be pretty close if everything is calibrated & setup properly.