Seems like ERG isnt all its cracked up to be

For doing ERG work, probably but don’t get too hung up on it. You don’t need to maintain an exact number doing your intervals. Stay within the “green” range on your TR wattage bar and you’ll be fine.

For Zwift racing, this is absolutely not the way to go…you need to have a wide cadence range. To some degree, power is of secondary concern when racing…you either make the split or you don’t. What power you are putting out isn’t really a factor. :stuck_out_tongue_winking_eye:. There are times when you’ll need to maintain a high cadence and others when it may feel like you are grinding…will depend on the race situation, grade, etc.

I think the main difference between erg mode and no erg mode is that, without erg, you have to concentrate to keep your power up. In erg, you can daydream, and you’ll still do the same power. But on the road (or zwift), you have to focus, or you’ll easily drift to a more comfortable power. If you’re not used to that need to focus, it can make the effort harder.

I use erg mode on my Kickr snap and I race tt’s …I assume that the trainer is requiring you to ride @250W if it says that on the screen . Now I know from racing with a power meter that even in a flat tt my power varies so it does on the trainer but surely if your power drops to much you just get the death spiral so the average power you put out is the 250W it says even though it varies with your pedal stroke. I personally like erg mode especially for V02/ super threshold intervals - it forces me to ride at the interval wattage rather than allowing me to fade - but if you look at the data post ride my power is often lower than the interval power as it takes a few seconds even in erg mode to get up to north of 350W. I would agree it is artificial though…it’s great for tt training but when I go on group rides especially chain gangs it takes a few weeks to get use to the power surges…If I was a road racer I would use resistance mode all the time.

This could be due to a difference in calibration between your kickr and PM, and not due to power smoothing or erg.

As step 1, keep erg on, switch off power smoothing, and do an interval where you can compare power between kickr and PM.

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This! Especially if it’s a snap, the wheel-on trainer as there are a bunch of moving targets that effect power readings as you’re adding the tyre/roller interface into the equation on top of the drivetrain (is it 1st gen snap? With that optical sensor that is pure evil?) The two are measuring power in fundamentally different ways too. Be very careful with the following if you do perform a test:

  1. Discard the first 10 minutes of data a la @GPLama, everything is warming up, don’t trust it.
  2. Do a spindown calibration on your trainer.
  3. Ensure that your power meter is correctly configured (crank length in the case of Powertap Pedals, nothing to do for crank-based) and zero/calibrate it in TR/head unit.
  4. If your PM is single sided (did you say what your PM was? Sorry if I missed it), your left/right imbalance will be exaggerated, your Kickr will not see this imbalance. If your PM measures both legs but only transmits one (thanks again Powertap P1 over Bluetooth specifically) again you’ll get an exaggerated imbalance. If you have a double-sided power meter on a newer Shimano crankset the driveside will be telling you lies (again thanks @GPLama)

As Dave says above, do a comparison run to see how consistent the two measurements are. As long as you aren’t seeing something egregious like the two measurements drifting apart over time (after they’ve warmed up!) then pick the PM and stick with it.

Also the PM saying it’s 16.5% lower? That sounds a little worrying but it’s not completely crazy. The Kickr could be a couple of percent high, the PM a couple of percent low, you might have a normal left/right imbalance being inflated by a single sided measurement if it’s on the weaker leg, etc.

This is making me relive this load of nonsense that, in a perfect world, us regular joe consumers should basically not need to worry about: Avio PowerSense Powermeter - owner first impression

Much ado about nothing as far as ERG is concerned.

However, your cadence is not steady.

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I train with ERG exclusively and can hold fairly steady power outside, I’m talking +/- 5% if I focus, you just need to form that muscle memory which takes time, maybe more than just a year of TR, it certainly takes working on outside as well. The real issue is your trainer giving you artificially smooth power lines, and you expecting a perfectly robotic power curve in the real world as a result of this deceit.

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The deceit is real.

Going to really work on the smoothness of my pedalling and power output so that i can perform these types of workouts outdoors as well - when this lock down finishes that is.

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True, and one key reason the Wahoo ERG smoothing is sooooooo bad!

It masked this issue instead of highlighting it as a potential issue, and something to be addressed by the rider. Seeing the direct power data exposes these kinds of problems so we can work on them.

Not many people pay attention to cadence, which is a mistake. It should be the primary focus when using ERG mode and getting the most from it. That helps the rider to learn control, but also keeps the trainer and controlling app working as best as possible.

Variable cadence just leads to a host of problems unless that is specifically what you are aiming to address. In this case, that floating cadence happened and was ignored as the pretty ERG graph from Wahoo gives the false impression of a workout nailed.

You’ll find that at certain power levels you are smoother at a certain cadence, but at others you may be smoother with a different cadence. Power spikes don’t bother me though, they are just a fact of life

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When I got started with Kickr (wheel-off) I thought having laser focused power training would produce better results. I have a very different opinion now.

Not sure what happened on that Zwift ride. I’d ignore it unless it happens repeatedly.

I don’t have experience with Snap but understand its a bit different experience versus the wheel-off direct-drive Kickr that I’m using. For what its worth this is what I currently do:

  • goal: setup trainer to more closely replicate the experience of riding outside
  • turn off Wahoo power smoothing
  • use TR PowerMatch to measure and record power from Stages crank-based power meter
  • use either Erg mode or Level/Standard mode (Bluetooth only)
  • gearing is big chainring and middle of cassette
  • always work on improving pedal stroke/efficiency

That most closely replicates riding outside. And its the same power source for both inside and outside.

In another thread I recently compared outside training ride at threshold to indoor trainer workout at threshold:

Bottom line: inside power with my setup is smoother than outside power, but close enough. In the real world power is going to fluctuate a lot more than on the trainer. Hitting precise targets on the trainer might work for a robot, but your body isn’t a robot. Train like you ride outside.

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my feeling as well from looking at that cadence, but its only one ride and you never know…

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Personally switch off erg mode and learn to pedal smoothly think of keeping the stroke nice and smooth as if you’re drawing a perfect circle with your feet. Try to work in a range. Over time you will become smooth without erg and avengly you will have be able to keep the power smooth even outside it just takes a bit of practice, learning what gear to be in how to brace your body. Here is the file from my ride today which was outside to let you see that a fairly smooth power line is possible. The smoother you are the less it will cost on a physiologic side

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I ´ve found this Video from Shane Miller:
[LINK]

He shows a effort interval with and with out smoothing the power data.
At the 2nd screenshot he sows the raw-powerdata and as you can see, the smoothing is just on the display and doen´t affect your performance.

Do i get it correct?

@Mitch54321 @ellotheth @GiacomoRz @iLLucionist @mcneese.chad @rjessop @bbarrera

#equipment

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yes.

As I understand it from TrainerRoad, turning on power smoothing may impact PowerMatch. A minor impact may not be noticed. I train with Wahoo power smoothing off, and TR PowerMatch. Works fine.

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It mainly affects the display. But my issue with it is that it masks and hides poor pedaling cadence and stability, that shows in cases like this one.

It keeps people from really learning what they are and are not doing well, so it inhibits improvement.

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exactly. When “pedaling bricks” (a small push over the top) my power graph is “rough” (but still less than outside). If I then smooth out my pedal stroke, I can see power become smoother.

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I’m pretty sure that is still ‘smoothed’, because the sampling rate for the TP graph is pretty low. There are a lot of data points to fit into the small graph, so they average some, which is what smoothing essentially is.

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yes TrainingPeaks smooths by default.

@Aaron_Wright you can turn off smoothing in the app:

Tap the control in top-right of graph, and then the first slider needs to be dragged to the left as I’ve shown in the screenshot.

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