Power Matching for ERG Mode

Can we get support for power matching when using ERG mode?

Meaning app will use our third party power meter as the source (ignore trainer's power meter) to reach the target power and control the trainer’s resistance accordingly.

Right now I'm having to use my expensive smart trainer as I would a dumb trainer. It's frustrating. I want it to auto control the resistance and give me ERG mode but also read from my power meter which I also use for outdoors training (for the sake of consistency)

I've checked another older post on this subject in which a rep said it was in the menu for 2018. Well, the year is almost coming to a close. As a new subscriber who really enjoys the app, I don't want to have to move on to other platforms where I can better utilize all my gear. This feature is CRUCIAL. Come on guys...



  • Hi everyone,


    I have managed to get this to work on my Wahoo Kickr. As someone has said above, you need to go into the newly updated Wahoo Fitness Android (or iOS) app....go into sensor settings, add your kickr and power meter as individual sensors. Then in the Kickr settings tell it to control with 3rd party power meter.

    Then, in the Sufferfest app, tell it to use ERG mode (of course) and also to do the power control AND the power readings FROM THE KICKR. You use the cadence from your power meter. If you have your head unit (Garmin, for example) to take power readings from your power meter, you'll find that the power readings will tally up with those displayed on the app.

    As someone else stated, I found the kickr added more resistance as the unit got warmer and warmer, making workouts too easy to start with, then too hard by the end (eg 100% FTP from my power meter may have been 95% FTP at the start, but as much as 105% by the end)'s always within 1% or so.

    I asked Wahoo about this and this update to the Wahoo fitness app (Android) was only released a few days ago, I have only tried it once but it worked absolutely fine and made me very happy, since I no longer need to tweak the intensity several times during a session.

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  • Interesting Ross,

    I'm just coming to this conversation because my Kickr has 4d power of it's own. 
    For a long time, spindown after 10 min or not, 
    50% or less at 90rpm, my Power2Max is 5~15w over target.
    90% at 90rpm, 10w over target
    90% at 60rpm, 20w over target
    110% at 90rpm 40w over target
    110% at 60rpm 50w over target

    For about the last two weeks the power matching seemed to work-ish. It would spike at the beginning of an interval but it would settle down as the interval went on (and the more difference there was between the power change, the more it would spike). This week, and even after todays update it's back to its old tricks where it is always over.

    I've just gone to slope mode for anything with sudden spikes because it's so frustrating for things like Half is Easy because it will ask me to do 400w but makes me hit 500+ watts which I can do for about 7 of them and then I crack. 

    I'll try your suggestion tomorrow.

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  • Interesting, because it's a power2max I have.

    Generally speaking the more power the interval is asking, the bigger the difference. 80-90% FTP was fairly close (about 5-10W difference) but FTP was 15W difference, and 120% FTP was 25W difference.

    I tested this for a 2nd time today doing Butter and it was pretty much spot on. Yes, first few seconds it would make me a little over (eg a 300W target may give 320W for about 3-4secs max) but then it'd settle and be spot on. Even the sprint at the end which was around 400W or so I think....pretty much bang on.

    Certainly made me very happy!

    My advice would be to double check you're running the latest Kickr firmware (I have the latest gen kickr by the way), otherwise, not sure what else to suggest. Doing what I said in my previous post it's been spot on. I've yet to try something really "on/off" like half is easy or the sprinting section of The Shovel but it's certainly looking promising.

    Just make 100% sure that the sufferfest app is set to use your kickr as the power source and your p2m as the cadence source.

    edit - what method were you using to do power matching before, if you said you'd try my method tomorrow (suggesting my method is different)?


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  • The app has been +10w since I started using it. Then a few weeks ago, it was power matching all by it self (with the overages at the beginnings but settling down to where it was supposed to be). Then late last week week, it's like there was a regression and I'm back to the +10w thing.

    I've got the latest firmware on the kickr.

    I tried to do your setup after my last post but I don't see anything like what you are talking about in the Wahoo Utility app or Wahoo app. I have a Ant+ only PM (no BT), and plugging in an Ant+ stick into my phone makes no difference.

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  • That's odd. I can only assume either the phone or wahoo app (it's the new wahoo fitness app, not the utility one) doesn't recognise the ant+....I connected my p2m using BT.

    Basically I did this:

    Update Wahoo Fitness app (it's a brand new design)

    open app up and add the kickr as a BT sensor

    then add p2m as a BT sensor

    go into kickr settings and there's a on/off switch/button thing for controlling with 3rd party ant+ source - make sure it's on

    then open and use SF app on PC/laptop etc as usual making sure the kickr is the power source.

    If you weren't doing as above then you have never been doing power matching at all, just individual readings from each sensor.

    Let me know how you get on.

    edit - Just make sure you go into the Google Play Store and see if you can manually update the Wahoo fitness app in case it's no done it manually

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  • The Power2Max Type S (older one without USB charging) does not have BT.

    To get Ant+ working on Android, I have an LG G7 on Android 8, Suunto ant+ stick plugged into a USBC to USBA cable.

    Then I installed: ANT USB Service, ANT+ Radio Service, ANT+ Plugins Service from the play store.

    I was then able to discover my power meter from the app and toggle the "Control w /ANT+ Power Meter".

    I'll try this today, GVA has me doing The Shovel and then 30 min of Endurance, I'll run my Elemnt to compare the power meter readings to be sure it's working.

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  • First off, Thanks for the help.

    If anyone reads frustration in my post below it is unintentional, I use Sufferfest because of the things I have tried, this app works the best to keep me motivated to train and to try my hardest. That said, as training season goes on, things get more specific and harder to do and having the power targets not match the output makes following the workout more difficult than it already is. 

    I didn't do The Shovel because it was all super short AC and NM which I just do on Slope mode because of the over power and timing issues I've seen. So instead I did Local Hero which has FTP, MAP and a dash of AC.

    This does seem to work a bit better-ish than the Power Match TrainerRoad had last year (which you could feel put on the brakes, I have not used their new AI version) but it's still constantly hunting for the right watts. The recoded watts was also lower than the power recoded by the Wahoo Elemnt for the whole ride by 250kj because the app did not show the same fluctuations as the PM on Elemnt (and that is more than just smoothing, there were times the Elemnt read 10w higher for 10 seconds while the app was locked in at the required power or 1w below it). The AC stuff was still wildly off by 60 watts for all of the 20 seconds I was supposed to do it.

    Frankly, I think this is the wrong approach to this issue. There is too much delay and round tripping for this to work effectively in real time. At least in my case, the differences between the two are generally reliable (maybe I'm special). I can manually adjust the target and it will follow along much closer but then I have to remember what my real target was so I can adjust as requirements change (because the app doesn't show the original target once you change it). If the app had a trim profile a user could input (or a workout to map it automatically) and adjusted the power requirements sent to the Kickr in the first place, then it could be much closer than what is going on now, which is basically trying to adjust after the fact. 

    For instance, the user target might be 250w, from the trim profile, you know that for a 250w target at 90rpm maps to 240w resistance, so you send the kickr a signal for 240w of resistance. The kickr will then make roughly 250w of resistance.

    Maybe I'm missing something but what's going on now is just a recipe for failure and disappointment.

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  • Sorry to hear my workaround didn't seem to work for you. It certainly seems different to my new experience which is great....although it shouldn't be Wahoo app programming the kickr to power match, it'd be better if the SUF app would do this.

    Until now, I too have been very frustrated with power differences between my power meter and the kickr....and the kickr changing when it gets hotter (meaning the power differences are greater as the workout progresses....meaning a change of a couple of % at the start of the workout isn't going to work for 1 hour into the workout.

    Fortunately, I seem to have got lucky with the power match on the wahoo app. Give or take a few watts it seems good from as low as 100W and up to 450W (about the highest I've tried so far).

    I have noticed the occasional lag, but it's no different than I have experienced before power matching was enabled (and it's fairly rare....maybe once per workout with quite a number of intervals. I did Butter yesterday and noticed it once. 

    The Shovel is on my plan, but not for a while yet....I am tempted to bring it forward as this would give the power match a real test.....and it's a cracking workout!

    Quick question - since ticking control with 3rd party ANT+ PM, have you noticed any change? If not, I'd suggest that it's that feature that isn't working.

    For reference, I'm not using a USB charging P2M, I am using the NGeco, which also uses a coin cell, although it is a newer unit (my old bike has a TypeS, but I don't use that bike on my kickr.

    Let me know if there have been any real changes to your kickr resistance since trying the power match. It would be nice to get to the bottom of it, I'd like to help, because I know all too well how frustrating it is!!!!!!!!!!!!!

    RE the power being well over for the first 10secs or so, I noticed some 300W target efforts might hit around 315W for up to 5-6secs but it soon settled/dropped a bit below by a few watts but then soon worked out and my 3s and 10s power averages were usually withing 1-2% of the target watts, even at 450W I think the max was 470W but it was a peak....the rep average was about 2W over and that was about a 15 second I don't think I could argue with that!

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  • edit - I totally lied about the power numbers. I've just gone back into the app and onto training peaks to double check and the last interval on butter is broken into 3 sections..... (excuse the low power numbers....I only weigh 53-54kgs......

    1st interval target 271W, 2nd 299W final sprint 380W

    Actual 1st 272W, 2nd 300W and final sprint 379W. 

    Good enough for me

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  • I know I've let this sit around a little, I've been testing things.

    The first is that the Kickr power match just lies and shows me what I want to see, power 1 watt lower than targets. I can't use something I can't trust, and I've been burned before by bad power reporting, so I turned that off.

    I took another 4DP test and my values all increased, now the actual vs target is worse.

    So I got a Tacx Neo 2, to remove the old Kickr from the equation. Plus the Neo 2 has +/-1% power accuracy and does not need a spindown/calibration (that requires doing a warmup then closing SF, opening a phone app, doing a spindown, closing that app to disconnect the Kickr, opening the SF app again, finding the workout and starting it 10 min in...). While the new trainer feels way better, not as jerky when power requirements change, a bit of flex in the legs that makes the bike feel a tad more natural, there is still a difference between the Neo and the P2M that may be a tad less (although I have not put the Neo through the wringer yet to really nail down how bad it is).

    So basically, the Sufferfest app is broken for me at this point and all the training plans and mindfullness in the world is not going to fix that.

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  • Hi all,

    I've been using sf for me than 8 months now. Initially on a old wheel on trainer. Using gears to match the required target sent from garmin vector3s. Recently upgrade to flux tacx 2 so I don't wake up whole family while training like it was on the old trainer. But the erg mode in taccx flux 2 gives 20watts less then my garmin vector. I understand power loss drive train explanation but with new chain and cassette that can't be that big.
    So it all comes again to sf users investing in equipment and software and yet not getting there that causes frustration.
    Can we ask Minions again to get on with the power match / control again pls?

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  • My experience is similar. Tacx Vortex. It produces 20-30w too much resistance for the first 15 mins (meaning warm ups are too hard) gradually getting into line after that, but the last 15 mins of an hour workout are way too easy, with resistance being 30w less than it should be.
    However, we’ve been asking for this feature for several years. They don’t comment, probably don’t read the messages. We’re tilting at windmills. I guess we have to accept that SF doesn’t work with real power figures, and maybe move to another system.

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  • Hi Arkadiusz and Richard,

    First, I am sorry if it seems like we have ignored this request. If you read earlier in this thread you will notice that I have previously commented that we are working on this.  We are not ignoring anyone.  

    It has taken far longer to implement than I would have liked but there were some pieces of the app that needed to change behind the scenes before we could start with power match.

    The good news is that we are almost there.  iOS power match is nearly complete and it's on its way for the desktop app as well.  

    If you are an iOS user please shoot me an email at and I'll see if I can sneak you into the beta so that you can try it.

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  • I would like to say I'm still finding the power match feature using the Wahoo Kickr is seemingly working quite well to be honest. I have done quite a few sessions recently and some involve pretty large jumps in power (I recently did Fight Club as well as Revolver is Easy....albeit different days!) and the power was always very close.

    Sometimes there is an exact 6 second delay in the trainer reacting, but I think this is software or trainer related, and it doesn't do it every time (even on the same video) but when it does kick in, the power is spot on.

    It requires you to go into the Wahoo app, pairing it to your Kickr and your power meter and in the Kickr settings choose "control with 3rd party ANT+ power meter".....then in the SF app ensure the Kickr is the power source, NOT the power meter. Then the resistance from your trainer will match the power meter.

    To have this feature built into the SF app would be more preferable, especially for those with trainers without this functionality, so I too would very much welcome this.

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  • How're things coming along for the windows app? I'd be happy to join in with any beta testing there. I can't help with iOS because my trainer is allergic to Bluetooth.

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  • We have the code all put together and ran full testing on iOS.  The problem I have is work capacity right now.  We need to redesign the device connection section so it's easier to understand and use.  Our design and UX/UI team is booked with other work through Mid-October.  I'll know in October where this falls out in our Quarterly planning meeting.  

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  • Thanks for keeping us updated. I followed your video to try an get my Elite Qubo Digital B+ vaguely calibrated against my power meter to try and get things as close as I can until power matching arrives, but the Elite app went weird. I'm looking forward to being able to see proper numbers when the power matching is ready.

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  • Hi guys, since its October, can You give us an update? Other guys have powermatch and we are stuck and frustrated with having to play with % changes in setup and seeing wrong values on screen and good in power meter...

    PS I'm using tacx bushido and power tap g3, I'm seeing 10% less watts on tacx compared to powertap.

    PPS I'm only interested in Windows version really....

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  • I thought I did something wrong yesterday when reactivating my SF account and didnt get the Power Match to work. Assioma DUO and Tacx i Vortex on Windows. Started to fiddle around with different levels.

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  • Are there any news for the powermatch? I signed the yearly suscription and thought this is a logical support, because the other plattforms offer this without any problem. I have no ANT+ adapter for my Iphone and want to use my windows before with Zwift. 

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  • Hi Hogler,


    We are working on it now.  I don't have a definite release date at this point but it is on our shortlist.  I hope it's out in early Q1 of 2020 for iOS and desktop but I can't promise that at this point.

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  • I'm currently looking at software platforms for this winter season, I asked for this feature years ago. please try to get it in ASAP. 


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