ERG mode on Zwift =/= ERG mode on TR?

I guess, plus practice the feeling of climbing.
I live in a place where a 65 mile ride yields 500 feel of elevation gain…
But I race on a place that 42 miles = 2200 feel of elevation…
(NEW 2020 GFT 1/3 Bike - A bike ride in Clermont, FL)


So if i pick something like balcony (
will it feel somewhat like climbing?
Or will i need something with more drastic changes in power…like intervals or something…

I’m far from certain that any trainer on the market will give enough of a feel change between, say, a long and a short gear at the same power (that’s really what we’re talking about here in terms of net effect) to make a training difference. You can get the same effect by a) going in erg mode and shifting to a short gear, or b) going in resistance mode and increasing the resistance, which will force you to shift down.

As far as trainers are concerned, whether the resistance setting comes from the simulation of a slope or an increase in the resistance setting, it’s completely transparent. In erg mode, that’s a different story (since the power vs speed curve effectively gets inversed).

  • Judging from my testing, and that mentioned by many others around here, assuming equal power in all cases, there are differences in “feel” when comparing a minimum gear (34x28) to a maximum gear (50x11).
    • Even if the flywheel falls short of “matching” the actual inertia/momentum that we get outside, there is a pretty noticeable difference in feel. We’ve discussed it in depth in the ERG gearing thread and I think most people admit there is some difference in “feel”.
    • I stop short of claiming any actual training impact difference, because I don’ think there is any data to that topic. I have some speculation, like most around here, and tailor my training with that in mind, but my use and needs may well differ from others.
  • Maybe???

  • If your aim with that was to get a “climbing feel”, setting a higher Resistance level in the app, that leads you into lower gearing and related flywheel speed, AND consider the cadence you expect to apply, I think that is worthwhile.

    • Again, might not match exactly to outside (depends on factors like your weight and typical climbing speed), but I would wager that the slower flywheel speed will “feel” more realistic than if you used a max gear like 50x11 to hit the same cadence and power data.

But that is based on my experience with my trainer and training history. Your trainer and history may differ enough that you don’t get the same feeling.

  • Again, great to test.
  • Start a workout with a power target, set Resistance to something like 15%, which will lead you to use a higher gear to hit the power target.
  • Then switch Resistance up to say 40-50% and adjust gearing to hit the same power target.

Pedal each one a bit to get the feel and then switch back and forth. See how each feels and decide if either aligns with your feeling and needs. I don’t have the answer for you, other than to suggest some quick and easy testing to see what you really feel at the extremes of the gearing and Resistance setting range.

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Thanks for your answer. May I ask Chad, what is the difference down to? Not sure I 100% get what powermatch means.
It’s such a radical difference that I almost never want to ride a zwift ERG session again.
I have a hard time understanding how such a big company like zwift can feel so poor compared to yours. Obviously that’s a big kudos to you guys! But yeah, just don’t understand how it can feel so different.

  • PowerMatch: Using Power Meters with Smart Trainers – TrainerRoad
  • PowerMatch is a method where TrainerRoad uses your power meter as the true source of power data, and then adjusts the resistance of the smart trainer in ERG mode, so you hit the desired power target with respect to your power meter.
    • In a sense, the power data from the trainer is ignored and your power meter is what matters.
    • This is used for those that want to have the same exact source of power data (the power meter) for use inside and outside.
    • It’s quite common that the power data from a smart trainer and power meter will NOT match. This leads to issues when the differences are rather large.
    • So, PowerMatch is meant to keep a more common “tape measure” in use for the rider to keep their power info more consistent.
  • If you are asking about the specific reason TR and Z feel different in ERG mode, I can’t answer that. All I know is that ERG mode programming (how the app reads and controls the trainer) can and does differ between apps.
    • There is not one “standard” way to do it, even though they are essentially following the same concept. There are differences like the way they read and/or react to your inputs and the trainer data, and then adjust the trainer to keep you on the power target.
  • For clarity, since I see the ‘you’ statements seeming to imply I am part of TR, I am not a TR employee. I am just a TR user that happens to help admin a bit on the forum. I am not Coach Chad Timmerman or any other Chad that is an employee of TR.

  • With respect to the feel differences, all I can do is guess. TR has been at this a lot longer than Z, and they have invested a great amount of time refining their ERG mode use over the years. This includes improving the PowerMatch feature to a latest and greatest 2.0 version that sounds great from all I have read.

  • I think Z has a basic function that fills the need, but falls short when compared to the more refined TR version.

Thanks a lot for your answer Chad! Kind of you.

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Just a follow up question!

What i was talking about before, apparently wasent powermatch. I was ONLY using my wahoo KICKR as the powersource and controllable. Today i tried to use my Stages L/R for the first time as powersource and my wahoo kickr as controllable. I guess this is where the powermatch comes into play. However i have a question about that. It feels like the resistance is on the light side, and when i change cadence, especially when i try to spin the power get`s too low.

However it did seem to improve during the workout. Take a look at this. The first rep of these low Z3 intervals was quite bad in terms of powermatching, but the second and third was better, and also felt better.
But still it`s quite diffrent to only using the kickr as both the powersource and controllable.
Lap/rep Watts also seem to be 5 watts lower than prescribed.

Is this normal?

What I see in the workout above is that you were far more stable in your cadence in the 2nd and 3rd intervals. The first has cadence bouncing around much more. This is a problem because ERG mode relies on a steady cadence from you. That is the most important thing, pay attention to and hold as stead a cadence as you can. IGNORE power data and let the system do the work. Maybe that is what you did in the later intervals?

More importantly, there is another issue to address here. If you had previously just been using the Kickr for power, here is a summary:

  1. You were using the Kickr trainer for power data, which means this is “Tape Measure A”.

  2. Adding in the Stages power meter for power data, means you just switched to “Tape Measure B”.

  3. As much as it sucks, it is quite likely that Tape Measure A and Tape Measure B DO NOT MATCH. There are many dozens of threads here with people showing differences between their power meter and smart trainer. The reasons are also many, but I am choosing to ignore that and focus on the more common reality, that you have 2 devices that offer different power data for the same actual effort.

  4. As such, and this applied to ANYTIME a person changes the device they use to measure their power data, you must redo your FTP test while using your new power meter device. There is likely a “new and different” FTP according to the new device.

  5. At present, you are performing work based on info derived from Tape A, but using Tape B, which means things will most likely feel different. Easy vs hard depends on which one reads higher than the other, and it’s largely irrelevant. You need to retest with the power meter, and use that moving forward.

  6. As a useful suggestion, you should consider creating a new Season to correspond with your power device swap. The fact that your data is now different means you don’t really want to compare to prior data from the other device.

Does that answer your questions?

Hi Chad

Thanks for your very comprehensive answer!
But no unfortunately it dosen’t answer my question.

  1. I didn’t ride a varied cadence on purpose. The resistance of the trainer was strange compared to effort 2 and 3. The resistance was changing a lot which was the reason why I had to try and increase my cadence all the time to get the power up. So it was the other way around.

  2. Today was my second ever trainerroad ride. So not relevant to re test my FTP or anything in relation to the data. I have just started to use trainerroad because I want to try trainnow!

I have been using my stages data for the last 4 years. Never the data from my kickr.

However when that’s said the kickr and stages is actually surprisingly close! Except for differences in acceleration.

Best wishes Malte