ERG vs Slope vs Resistance

I could not find anything usefull on this on the Support Page - so I therefore was wondering if you could post a link to how this works/differences? I a planning to do a Rønnestad today to update my signature - and thought it would be helpful to know the differences of how these work.

I am using a Garmin 1030plus with my smart trainer.


Use Slope mode for your BT effort workouts so you can over-ride watt targets (if able) especially as you hit the BT zone on a final set.

ERG = trainer is controlled by app to the fixed watts value shown regardless of how you are pedaling or what gear you are in; in Xert this manual option does not follow the workout targets

Slope = simulates a pitch so that you change gears and cadence to hit watt targets

Resistance = sets a resistance level similar to applying brakes; works like slope if you find the right % for your desired gear range

AUTO = Xert player controls whether ERG mode applies to match workout targets or Slope mode is in effect; workouts tagged MIXEDMODE switch modes automatically

If you don’t mind waiting a few days there is a group BT session scheduled on Sunday – Xert - Breakthrough Sunday Ride - Ronnestad (


There is a support document for this, but it looks a bit outdated. We can work on getting it updated to include Xert EBC :slight_smile:

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Så langt jeg har kommet med dette er at ERG mode ikke virker. Auto mode derimot virker slik som ERG er forventet å virke. Bruker en Stages SB-20 og har «delay» i auto mode, så har gått over til å kjøre alt i slope mode med 2% gradient.

Hi Ole,

You’re correct - ERG mode in Xert EBC is a manual ERG mode - i.e. 100 W, 125W - it does NOT follow the workout. If you want trainer control during your workouts, then use the AUTO setting. If you prefer to manually control your effort, then use the SLOPE setting. Cheers!

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Quick question. When I’m using trainer control, (Auto) if I stop pedaling for a moment, but then attempt to continue with the workout, the effort feels like 2000 watts. It stops me in my tracks, and I have to pause the workout to see if it Xert will free up the flywheel. Is this normal behavior?

Yeah, sounds pretty typical of the ‘ERG Spiral of Death’. You can google it to learn more of the specifics, but in general, as your cadence drops, the trainer needs to dramatically increase resistance to maintain a set effort (e.g. 200 W), which usually causes cadence to drop further, and resistance increases further, and so on…

Usually if I need to stop for something (grab a snack, water, etc.) I wait until I hear the trainer fully stop the flywheel before starting to pedal again. EBC will ease up a bit as you get started pedaling until you’re a few seconds back into the workout, when the proper resistance will kick back in.

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I don’t have this issue with my Halcyon which relies on wheel speed to generate resistance. MIXEDMODE can cause problems but the transition from coasting to resuming an interval doesn’t normally trigger the death spiral.
However, I still have my Hammer 1 (aka The HOWLER) and the way to handle the death spiral on that trainer is to backpedal for a few seconds. That lowers resistance so you can resume an interval at the target watts. The higher the watts the faster you must resume a normal cadence.
Next time you stop pedaling during an interval try the backpedal trick and see if that helps.

I think that works. I did a tiny bit of experimenting, did some back-pedaling and the fly wheel slowed even more quickly. Once it stopped, I could begin again no problem. I need to do some more experimenting.

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Just started with Xert and I have a couple questions regarding erg mode:

(1) can I achieve a breakthrough while in erg mode? Wouldn’t erg mode limit my power output?

(2) I’ve been uploading Xert workouts into FulGaz. Would this change things? Would erg mode in FulGaz allow for breakthroughs?

I guess my question overall is: what mode should I use to allow for breakthroughs (both in Xert and in FulGaz)?

It’s possible to have a breakthrough in erg if you build a workout that way or increase above 100%, but it’s preferred in slope or resistance mode so that you can fully go to failure, and have a more ‘natural’ failure pattern