PowerMatch Experiences

All but a very few in here run Kickrs. Anyway, I have a Direto also and Garmin Vector 3 dual sided. For the most part it works well. Yes, sometimes it feels the ramp ups lag a bit but usually the trainer catches up quickly. There was a workout recently when I didn’t get resistance changes, as if the trainer was in slope mode. This happened during the warm up, I paused the workout, calibrated both PMs and got stuck back into it with no problem. Very occasionally I get power drifts, usually down, for a few seconds. It’s frustrating during the moment but usually doesn’t have a significant enough impact on the interval NP/Avg to even remember this for further analysis after the workout.
As for “reading low/high” I don’t think it reads significantly differently than the Garmins. My first ramp test with the pedals resulted in about 20W lower than my last on the trainer alone but I wasn’t in a good space that day, I probably pulled the plug a little too early and my trainer had been in a bad space for weeks. If anything I feel it’s making me pedal more smoothly. The increments in which power changes are displayed in the app are a lot smaller, despite same power smoothing etc. On the trainer the jumps during ramp up/downs would be dozens of watts while with the Vector pedals it jumps more frequently by far few watts. The result of course is exactly the same.

I changed a few things today, bad scientist that I am it means I can’t isolate the one variable that changed things.
Today’s workout was Leavitt +2 (second week of SS mid vol 1). I changed the Kickr to be controlled by the Stages R power meter and I didn’t have Zwift playing through the second ANT+ dongle (I found some podcast about cycle training instead :wink: ).
I thought this was different, although the workout was hard about one hour mark (and boring man I don’t need Leavitt again in a hurry) I was able to spin faster, more naturally around 92-94 rpm and if I increased my cadence it got easier. I did think there was more of a delay in the power changes though. I also calibrated right before the ride, normally I only calibrate once a week.
So, I’m going to try this setup for this weeks workouts, hoping to see a difference in the Saturday threshold workout.

Mid ramp test trainer calibration because the target was 30W higher than the trainer would give me. Then again the Vector 3 pedals wouldn’t play along at first, I got only left sided power. Not a good morning for testing… but eventually at around 80% FTP it all started kicking into gear properly.

@rbuder, I’ve had a similar experience with occasional disconnects between trainer and pedals when power matching, but if I remove the times I found something other than TR had grabbed the trainer (oops), it’s rare. Usually, power cycling the trainer fixes it. I’m assuming it’s probably a timing thing with the different devices making a connection, the Direto snoozing, etc.

I’ve also seen power drifts like you describe, but likewise rare and small.

On the trainer, I’m spending a lot of time driving for a stable cadence because that seems to do more for power stability than anything. I’m guessing cadence variation affects my pedaling pattern and force, flywheel inertia, and other factors that destabilize the power matching feedback loop for a while.

1 Like

Not sure what was going on this morning, I’ve had something similar happen at least once before as well.

I did the ramp test, which starts out at 47% FTP. Just spinning the legs at a comfortable cadence is about enough. The first step up to 53% is merely a slight upping of the RPMs as well, and my measured power stays close enough to my target power to not worry, although I did wonder already at that point whether something is wrong. I do tend to gradually increase my cadence throughout the ramp test however, as I would outside. When the trainer did not increase the resistance during the second step and finally still not during the third step (it was just giving me a flat line) I stopped, did a spin down calibration and then continued, at which point things were fine.

I then completed the test, accepted defeat…erm I mean my new FTP, had to get out of the saddle to get the trainer spinning again. Not sure if this is a Direto special (and it goes beyond the scope of this thread), but when I stop pedalling in ERG mode it cranks up the resitance to the max and leaves it there, no amount of back pedalling seems to resolve that.

In any case I ride with a stable cadence as well and don’t much deviate unless being told so (aside from the aforementioned drift up as the power requirements increase, but that drift is gradual, from about 85 to failure @ 101 over the space of about 15 minutes).

Here’s a video as to how to open the developer options using Android:

The current production firmware seems to be the most recent, so I don’t think there’s any need to switch to beta firmware, but I believe this is how you get to the “switch to external powermeter” option which requires a password.

4 Likes

@justinm I have a Wahoo Kickr 2017 and a Stages single sided (left-only) power meter. What I found is that sometimes Zwift will switch from power meter to controllable trainer. Yes, mid ride, and when that happens as you say “the experience was awful” as you have both TR and Zwift trying to control the Kickr. It probably happened at least 5 times, maybe more, while I was running both TR and Zwift simultaneously over the course over a couple months in late 2017 and early 2018. I tried configuring Zwift and TR in as many permutations as possible to avoid Zwift trying to randomly grab control of the Kickr, but was unsuccessful.

That was another reason to drop Zwift, in addition to paying an unnecessary (for me) expense as I prefer to choose my entertainment while training.

When TR+Zwift worked, it worked great. Even when using Stages for cadence only. As far as options, I turn “Erg Mode Power Smoothing” off because it lies to you - your power is not really that smooth. Other options are the same.

(I have successfully used Erg Mode Speed Simulation, where the Kickr calculates speed based on power, instead of flywheel speed. However it is not working for me on the latest Kickr firmware from June or July 2018)

Made one more change, turning off Erg Mode Power Smoothing in the Wahoo app. There is still power smoothing via the TR app, set at 5 sec. I wonder if the two power smoothing settings were conflicting? I’m pretty happy with the set up right now, although Saturday’s threshold workout will be the judge. Current settings are:

Wahoo Kickr 17
iPhone Wahoo Fitness App v3.4.67
Erg Mode Speed Simulation = off
Erg Mode Power Smoothing = off
Control w/ANT+ Power Meter = off

Stages Right Power Meter
iPhone Stages App Firmware 1.2.0

Connected to TrainerRoad Windows PC app via ANT+
Mode = Erg
Power Match = Auto
Power Smoothing = 5 seconds

Same experience as many above. Discovered that my Kickr gen1 was reading high (maybe 5-8%) after installing a Quarq. Kickr also became a bit erratic after 60-70 min workouts, I was unable to get it resolved by Wahoo and decided to switch to PowerMatch. It worked out for me (except that initial mental setback when I dropped my FTP to reflect new lower-more-accurate Quarq reading). Pierre.

I just did “Antelope” a sweet spot workout on my Tacx Vortex:

The first half of the workout was done with Power Match. As you can see, the power was very erratic and it felt harder than what I would expect it should, possibly due to the fluctuations. In the second interval, everything went haywire, including my legs! Even though I reduced the intensity to 95%, I couldn’t keep up, and had to back pedal several times! Very odd for a sweet spot workout, unless my ftp is set much too high. Compared to an outside test not that long ago, it looks about right though.
When looking at the Devices screen, I saw that my power meter and the trainer were pretty close, so I decided to just use the trainer’s power for the rest of the workout. That made a huge difference! I know the trainer artificially oversmoothes the power and you can’t expect the power reported from a power meter to be as smooth, but I think it should be better than this. For example, at one point, I was supposed to do 177 watts, but Power Match stuck at 155 for 12-13 seconds. That does not seem right?

I’ve had very similar experiences with my KICKR3 and Stages R, to the point that I’ve gone back to using the KICKR as the power source and the Stages for cadence only. I know there is a difference between the two power meters and that the KICKR appears to read low, but really power match has just been too much hassle for me, it’s way too hard on the over/unders and the reaction to power increases requested by TR is way too slow.
I would really like to spend some time exploring different combinations of the power meters and the software settings (I have a suspicion that settings in TR, Wahoo and Stages software cause conflicts) on the same TR workout but I don’t think I’ll have time to do that until around Christmas.

1 Like

FWIW on both my iPhone 7 and MacBook Pro, I’ve had zero issues with Bluetooth no matter the settings.

With ANT+ there have been issues with dropped signals from time to time. For example, Nate was kind enough to look at one of my support requests and said there were 63 dropouts from my Stages power meter when connected by ANT+:

While it wasn’t a real problem, my solution was to stop using ANT+ and switch to Bluetooth.

If you go to DCRainmaker’s review on Edge 520, or Garmin forum, you’ll find a lot of people have ANT+ connectivity issues with Stages power meter.

@justinm given all of that, I suspect your real problem is using ANT+ and your Stages is broadcasting a weak or flakey signal on ANT+

1 Like

@Nate_Pearson care to explain the reason for skipping single leg work on erg mode? was your thinking due to single sides power meters or this also applies to dual?

I’m not Nate lol, but using single-sided (left) power meter means that one leg (right) will be pushing hard and registering 0 watts. If auto-pause is on, then workout pauses.

If you have a dual side PM you can totally do single leg drills.

Reading all the posts reporting suboptimal behavior with power match, why is there a need to match at all?

Wouldn’t it be possible to read two data streams? One from the „regular“ power meter and one from the trainer. Then internally use two FTP values, one for display and one for setting the power targets.

This way there wouldn’t be a need to add the complexity of trying to force two measurement and control systems to work synchronously.

2 Likes

Its a mater of consistency. I know the power meter on my training bike, and my race bikes, are very similar and consistent across a range of efforts. By trainer is less consistent and the power output is different to my on bike power meters. By utilising the power match feature I know that the effort on the trainer is similar to that on the road.

1 Like

If you, or anyone else, legitimately feels like there are more significant power changes with power match the following steps might be a good way to test whether it is your head or your legs that are telling you the difference. Required equipment would be smart trainer with erg mode, power meter, device running TrainerRode, second device to record data.

You could then test both ends of the spectrum

Setup 1 - Pair trainer with TrainerRoad but do not pair power meter. Use erg mode (obviously without power match). Pair second device with power meter. Record the same ride on both devices (I’d be using my laptop for one and my garmin for the other). Then compare the power from both.

Setup 2 - Pair trainer and power meter with TrainerRoad. Use erg mode with power match. Pair second device with trainer but not power meter. Record the same ride on power devices. Then compare the power from both.

Setup 1 would give you a baseline on how much your actual (measure by the power meter) power varies when you are in erg mode and you’re seeing those sweet sweet straight lines in trainer road.

Setup 2 would give you the comparison point to see whether or not the trainer power is varying as dramatically as you think it is or if you’re still getting that sweet sweet straight line.

This wouldn’t give you enough real comparison points to compare responsiveness (you’d need to do a bunch of dramatic power changes over the course of several rides to get a large enough sample set - say Spanish Needle done 3 times in each setup) but with even one execution under each setup of something like Mount Field you’d get a decent enough comparison point to know for certain

3 Likes

I set my kickr up to use the vector3 pedals as the power source, turned off power smoothing on the kickr, then in TR setup the vectors for cadence only and turned off power match.

It seemed to work really well, with intervals responding very quickly and feeling consistent. I had power smoothing set at 3s in TR.

1 Like

display only, does not change how kickr responds.

display only, does not change how TR records data (or controls kickr).

I tried Kickr power control, and PowerMatch using Stages. No real practical difference between the two in my garage. For convenience to enable/disable, and so that power inside is same as power outside, I’m using TR PowerMatch.