Indoors on my Wahoo
ERG Mode - 122 Watts @ 85 RPM
Standard Mode - 122 Watts @ 95 RPM
I calibrated my Wahoo before each ride.
Any explanation about the difference in my RPM’s?
Thanks
You spun your legs quicker 
In erg mode the resistance alters so that the power is constant regardless of cadence.
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Generally in all types of my indoor rides are done in Erg. I my rpm’s are slower and I believe it will have a bearing on my outside rides and races. I used to believe a high rpm or spin as we called it was better as a way to conserve energy.
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Erg mode attempts to keep the watts needed the same regardless of cadence. So you could spin at 50rpm or 120rpm and it would alter resistance to keep the power at 120w.
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If you’re not understanding what folks are telling you (erg can be confusing), start a workout in erg mode. Make sure the interval is at least a few minutes long. Spin your legs at 70rpms for 30 seconds and then spin them at 100rpms for 30 seconds. It may take a few seconds, but 10-15 seconds in, no matter the cadence, the power should even out and be the same as the target watts for the interval (plus or minus a watt or two for variance). So, let’s say the interval target is 200 watts. Whether you spin at 70 rpm or 100 rpm, it should settle in and put out 200 watts. If it does not, you are not in erg.
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Define “high rpm”.
As always, it depends. If you are comparing 90rpm vs. 70rpm, yes, that would generally be true.
In the example above of 85 vs. 95, it likely doesn’t matter. Let your cadence self-select and don’t focus too much on it.
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High RPM is 95-110
I’m finding the ERG mode keeps me in the 80-90 RPM’s
I think going forward I’ll stay in Standard which allows me spin high or not.
- ERG mode is not “keeping you” in any cadence range. You are responsible for your cadence at all times in ERG, period.
The X-factor here that has not been mentioned is flywheel speed related to the gearing you use in either mode.
- How similar or different are the gears you are using for both modes?
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Erg mode does not force you to spin a specific cadence, literally all you have to do is increase your cadence and the trainer will adjust the resistance to keep the watts at its target.
It’s not instantaneous so you might have to give it 10-15 seconds depending on your trainer.
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Reread this if you think erg is forcing your cadence.
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In defense of the OP’s experience, and tagging on what Chad M said, I think Erg mode does tend to push many people to lower cadences, especially if you are using small ring and/lower gears that tend to reduce the flywheel effect of most trainers. And this is what TR tells people to do.
Using my Kicker in the small ring with a middle of the cassette position feels like pedaling thru mud through the entire pedal stroke because you are getting so little advantage from the flywheel effect to keep moving. And I think this feeling forces people to muscle through the stoke, promoting a lower cadence. I know some people like this or think it gives them a “better” workout, but I hate it as it doesn’t feel anything like riding outside.
So I generally prefer to use standard mode, or make sure you are in the big ring and middle of the cassette.
But if you just spin faster, that goes away, right? (I don’t use erg anymore either, but I understand how it works)
Not in my experience, no. This is a physics issue of getting the flywheel up to a speed that “helps” your pedal stroke. This isn’t a software issue.
Admittedly, I am way over my skis here. I hesitate to even type the word physics. But from my non-science background I think this is what is happening here.
Ok, I think KonaSS has correctly defined what I notice when riding in ERG.
It feels like I’m working harder, spinner slower and I feel that Standard mode is something similar to riding outside. Outside we get micro-rests because of the various undulations of the road terrain. I do feel that ERG is a harder and better effort because you are always on and you can’t cheat in your pedal stroke.
Yes, the lack of micro-rests makes it more stressful for sure. I don’t use erg any more because over time that strain adds up and screwed up one of my knees.
Is 122W towards the low end of the power that the ERG jiggery pokery on the machine can cope with?
Depends on the trainer, but I don’t know why that would be a problem, generally speaking.
Can we try to define “micro rests”?
Because I doubt there is a real difference in trainer modes here, from my experience.
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No trainer adjusts ERG fast enough to prevent subtle variations in power. It’s evident in the power profiles for anyone not using the insane smoothing that Wahoo applies by default. Once you look at real power data, the variation I see in ERG is on par with other modes.
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For the other two modes (STD & RES) they are more “normal” in the sense that you push harder to get higher power and vice versa. BUT… neither of them introduces the “micro rests” mentioned from road pitch changes, wind and such that we get when riding outside.
- Once you settle into a gear & cadence in these modes, the power is steady and looks just like ERG in my testing. Nothing is changing other than the rider input via power & cadence. If these are held steady, it is no different from ERG (presuming the same gear ratio & flywheel speed).
I mention these details because the statement “It’s more like outside…” gets applied to STD & RES, often with the “micro rest” aspect as a reason. I do agree in the difference in basic effects of pedaling harder/faster between the modes, but the “outside” aspect isn’t part of the equation from what I see.
For people wanting the closer approximation of outside, Simulation mode via Zwift and others is the better direction to point. Those introduce variation of road grade, but not wind or other variables.
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Hmm… all the micro rest stuff is true but that is related to the flywheel speed and what gear you are in… It won’t be different between standard and ERG if the gear ratio is the same.
In your original example, with the 122w power output, that seemed like what you were dealing with wasn’t that ERG mode was forcing you into a low RPM - rather you were missing the feature of standard mode that allows you to force yourself into a high RPM by switching gears.
On standard mode, if you were holding 122w at 85rpm and wanted to increase your cadence to 95rpm then you would change gears - just like outside.
You don’t change gears in ERG mode, it’s like driving and automatic, you just spin your legs quicker. This can get some getting used to and probably is harder to force yourself away from your natural cadence.
The other feature of ERG mode, and this is what I think pbase may be referring to, is that the mode of failure is different in ERG mode than in standard. In standard mode if you are struggling to maintain a high power target then the power output will go down as you rpm drops. In ERG mode your RPM drops first but your trainer then increases the resistance to keep the power the same so you end up pedalling through treacle - this is what you will hear called a spiral of death. Different trainers handel this better than others.
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