Power Matching for ERG Mode



  • Avatar
    Alex Knol

    I am trying to switch from Zwift to The Sufferfest (TSF), but this is a feature I've always used in Zwift and would really like to see it in the app. There is about a 10-12 watt difference between my crank based RotoR power meter and the Tacx smart trainer I have. I'd need to manually play with my FTP or 4dp values to match power output for outdoor rides.

    The compelling feature for me to come to TSF is that outdoor rides are a first class citizen as opposed to TrainerRoad.

    Posting a comment here to be notified when this feature is in the app.

  • Avatar
    Ken Bayne

    If you have a KICKR you can backdoor a power match feature. In the Wahoo Fitness app, select your Kickr, then enable "Control w/ANT+ Power meter" option and then select the ANT+ ID for your on-bike power meter. In this way, I'm able to use my QUARQ power meter to provide power data feedback to the Kickr. Works great and seems to have the same end result as using power matching directly via the app (the way it works in Trainerroad, for example).

  • Avatar
    chris mohr

    Ok-I have a SNAP.  But this won't work unless you have an ANT key for your phone, right? What if you're using a laptop w/ant key?  How would you do this?  (Can't believe it's taken them this long to implement something that other platforms have now had for years).

  • Avatar
    Ken Bayne

    I am using a PC-laptop with an ANT dongle and no ANT key for the phone. The step by step for me to get this to work with my KICKR was as follows

    1) Enable bluetooth on your phone and open up the Wahoo Fitness App

    2) Find your KICKR inside the Sensors menu, select it.

    3) Enable the "Control w/ANT+ Power Meter" option. Be sure that you enter your ANT+ ID from your on-bike power meter

    4) Do a spindown (not sure if this really matters, but it can't hurt)

    5) Inside the Sufferfest app, use the KICKR as the power data source and use your power meter as the cadence source only. Note that if you select your power meter as the power source it breaks the workaround

    In reality now, your power meter will provide the feedback loop to the KICKR (outside of the SF app), but the SF app will "talk" to the Kickr to give power targets. The Kickr will also report power (as measured by your power meter) back to SF app.

    Sorry I can't provide SNAP trainer specific info, but the general process hopefully is applicable to other models.

    On an ongoing basis, you do not need to have the Wahoo Fitness app open on your phone (and in fact, I'd recommend not having it active at all to avoid any possibility for 2 apps trying to control the Kickr at the same time)

  • Avatar
    Taro Narahashi

    Tried the above on the kickr but didn't work.  Frustrating that sufferfest has yet to implement this feature. Been using sufferfest for 4 yrs.  Will get rid of my inaccurate kickr or finally move to another platform.

  • Avatar
    Timothy Flott

    I would really appreciate not having to play with my intensity numbers to have an accurate workout. It’s quite annoying to not have power matching. It’s one of the only things that keeps me using Zwift as well

  • Avatar
    William Hardie

    I was expecting this to be the norm, fortunately I have a Kickr so ill be using that work-a-round. Hopefully it still works, cheers Ken Bayne.

  • Avatar
    Richard Starkie

    How come no-one from The Sufferfest has replied to this?  Anyone know if their staff read this section?  I too remember saying that it was on their to-do list for 2018.

    I have a Tacx Vortex with Garmin pedals.  If a calibrate normally, then the two are well over 10% part.  Pedals say 260W, Tacx says 290W+.  I can cheat the calibration to get them to match, but then it goes way off as the trainer and tyre warm up.  by the end of a session they're miles apart again.  

    If not power-matching, then an on-screen, in -app calibration thing would be nice.  When my trainer tells the app is producing say 290w of resistance, I want to be able to tell the app "no, that's actually 260w".  Then I can train on my trainer without having to use the power meter, knowing the trainer and app are producing realistic numbers.

  • Avatar
    Cody Moore

    Hi Everyone!

    Power match is coming.  If you look at the 6.0 app you will notice that our method for device connections has changed.  One of the main reasons for this is so that we can get this moving.  I can't give a timeline yet....still.... I know (I want it just as bad as all of you here). 


    I promise though, it is coming, and I'll keep bothering the SUF team about it until it is here.

  • Avatar
    Antony Smith

    Good to know it's coming...


    Will try the power match again.  I tried a few months ago but was unsuccessful.  Just didn't seem to be anywhere near the stages output on my Garmin.


    With my kickr the resistance appears to increase as the unit warms up.  I keep it in the house now, next to a radiator so it's a bit warmer than the 0 degrees that it would be in the shed.     Starting then around 20 degrees and having done a spin down we're fairly accurate, but 15 minutes into the workout the temp has risen and so has the resistance - leading to about 10-15% extra based on stages (and legs!).

    This is pretty brutal at prescribed 350-400w!!   Does mean that I have issues completing workouts - or I need to adjust down the dials, and who likes doing that!!


    Have a couple of days before the Tour, so will have a play and see if I can get it right...

  • Avatar
    Lea Nadler

    Relieved to see this - I thought I was doing something wrong.  I have a Kinetic Smart Control and I use both the Kinetic Fit app and Sufferfest in my training plan.  They use the same trainer but the power readings between the two programs are VASTLY different  - my Sufferfest FTP is 75 watts higher than my Kinetic FTP!   I can't figure out a good way to reconcile them.  I can do a spindown calibration on the Smart Control through the Kinetic app, but there certainly doesn't seem to be a way to do that on Sufferfest.

    I'll keep an eye out for the power matching.

  • Avatar
    Cody Moore

    Hi Lea,


    Are you using Virtual Watts in The Sufferfest app possibly?  If so that'd be the difference.  If you are connecting the Smart Control to the app, we should be reading power right from that.  

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