Erg mode for short and sharp intervals

You might find that for shorter burst type workouts, it might be worth switching to the big ring throughout, so that your trainer doesn’t have to work as hard to ramp itself to the desired wattage. Might mean slower cadence in the rest periods but I’ve found I can hit higher burst powers this way

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I actually think the general consensus is the opposite of what you’re recommending. Some (not sure if all) smart trainers definitely ramp up power faster, and maintain that power smoother, using the small chainring and a large-ish rear cog. This helps to keep the flywheel speed down, which actually helps the trainer apply resistance more precisely. I admit to not knowing the physics behind why that is so, but it is recommended by lots of people, and I can personally confirm it. I believe that TrainerRoad has in-app recommendations to this effect, and I’ve read it from their support staff as well.

On a side note, the small chainring/large cog effect that keeps the flywheel slower also helps with noise on some trainers (older Kickrs, for example), and helps to lower the “resistance floor” of the trainer… the lowest point at which it can maintain consistent resistance. I haven’t personally experienced this, but it is out there for certain trainers, in certain situations.

The only aspect where being in a larger chainring can “help” is that the higher flywheel inertia helps you to keep the pedals turning a tiny bit easier under high watt loads. I have found this benefit to not be worth the significant loss in power smoothness though (fluctuations +/- your target wattage are much higher in my experience). Maybe that’s just my OCD at wanting nice flat intervals though. :wink:

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The resistance floor can clearly be seen when doing the exercises on a handbike, as we have significanly lower wattage compared to the bikers. For ex. on the recovery phases, the needed wattage might be around 40-50W. That’s so low, that on Kickr Snap, I need to you for ex. 39T/25T on a 26 inch rim, so that the flywheel speed is low enough to keep the wattage stable, not fluctuating too much.

As an example, here is the power curve for Kickr Snap:
https://www.google.fi/search?q=wahoo+kickr+snap+2017+power+curve&rlz=1C1GGRV_enFI779FI779&source=lnms&tbm=isch&sa=X&ved=0ahUKEwifzfed65HeAhUGCCwKHbp1DdUQ_AUIDigB&biw=2560&bih=1298#imgrc=rSqvykoroBzp1M:

I’ve regularly felt let down by the ability of my kickr to react to short intervals of power spikes in workout both with and without powermatch.
I’m back using powermatch again and noticed prior to tonight’s workout an app update was available that indicated improvements in powermatch performance.
It wasn’t perfect but I would say a lot better than I’ve experienced previously.


Good work guys, hoping this is the start of regaining my trust in these types of workouts.

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I’m also struggling with this. I use and Elite Direto in ERG mode. It does not look like the trainer starts to ramp up power until the interval starts (not a few seconds before). With the sharper intevals that are less than a minute I generally miss the power goal that is shown in the summary at the end of the interval by 10 watts. I have power smoothing set to 0 in the TR app and the Direto app. Is there a setting to get the power to start ramping up a few seconds before the interval? It seems to take around 5-8 seconds to get to the goal power which can be a significant part of the shorter intervals. I’d prefer not to manage this by going to standard resistance mode, but that is what I have been doing.

  • It appears that TR already sends the resistance change to the trainer around 1-2 seconds early. My experience with a CycleOps PowerBeam Pro, Hammer, H2, and Kickr all show the early sending in effect.
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Thanks, Chad. I appreciate your quick response. I reviewed the data and zoomed in on the intervals. You are right, I see that TR is changing resistance 1-2 seconds early. However, I am consistently seeing it take 6 seconds (from the start of the interval not the resistance change sent from TR) for my power to match or exceed the goal power. Is this about what I should see? If it is, I can go to resistance mode for workouts that have one minute intervals or shorter, I just prefer to stay in ERG.

  • “Should” is relative. In general, I would saw, ‘No’ that is not what you “should” see in a proper workout. The problem is that you happen to have a problematic trainer that doesn’t adjust resistance quickly or consistently.
  • I suspect much of your issue is explained in the testing and oscillation shown in this video. I know it’s not the same trainer, and the Direto might well be a bit better, but from what I have heard, the Elite trainers are not as quick to respond and adjust when compared to other trainers.

So, with that trainer, it may be the best that you can expect. I can say that I have a reasonable experience with all the different trainers I have used (CycleOps and Wahoo).

Just think though, when that resistance changes you’re jamming on the pedals, the trainer can only see what it is doing, not exactly what you’re doing, so even during that ramp up, I bet if you had a proper power meter you’d see much more accurate and closer figures than that of the trainer. :thinking:

Not sure. For reference, here is a workout with jumps:

TrainerRoad with power data from my H2:

Strava with power data from my P1 pedals:

I am seeing very similar profiles when looking at the finer details of the jumps.

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Are you using power match or are the trainer and pedals completely separate?

No, I am not using PowerMatch.

My seat of the pants comparison show the differences to be in single digit watts, so I don’t bother to pair both in TR.

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Sure do. Have you tried importing the Strava data into TR so the graphs are same? TR graphs are better for looking at second-by-second data like that.

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Suppose it could depend on the interval % jump and the type/make/model of trainer.

I just had a look at my workout this morning (Taylor -2) and while it shows at the time approx 6 seconds to ramp up to power, the after data actually only shows 3 :thinking:

I haven’t bothered, but probably could/should. I may try DCR’s tool.

I am trying to get both into TR and having no luck for some reason. The check box fills out and I don’t get an error. But after refreshing, there is no new ride in my list.

Might be a duplication issue?

that would be my guess, and I’d file a ticket. I’ve seen Strava take multiple rides, say one recorded on Garmin and one recorded using Strava mobile app. But that sometimes fails too, as a duplicate.

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Maybe im off topic, but I thought TR advises to use resistance mode during very short intervals

–> 2. Sprint intervals - ERG trainers perform a brief ramp up to an interval’s target power. For longer, less-intense intervals, this ramp-up is hardly noticeable. However, this ramp is more pronounced for short, high-intensity intervals. If an interval is between five and 20 seconds, riders may want to consider riding in Standard/Resistance mode to avoid any lag time in reaching their target watts.

They may advise that, but I have great results with ERG even down to 5 sec sprints.

I use ERG for ALL of my workouts.
(CycleOps Hammer & H2, Wahoo Kickr17, CycleOps PowerBeam Pro, CycleOps Magnus)

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I’m also happy with Erg down to 5 seconds. Using a 2017 Kickr wheel-off / direct-drive.

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