How to best hit 30 second intervals on ERG mode in TR

Did Spencer -2 today and found it really tough to hit the 30 second power targets with 30 seconds on, 30 seconds on. Have Spanish Needle with its 15 second microbursts coming up next week, not sure if that will be harder or worse. Using Erg mode I find to hit the 30 seconds power I have to spin up really hard and fast and way overshoot the power and then as Erg mode eases the resistance in response I have to slow and speed up my cadence up and down to keep the power from dropping off as my cadence gets too high.

Power target was 257 but I found I would spike above that (up to 362 as a max) but with Erg mode responding by quickly dropping the resistance my cadence was getting very fast for my pedaling ability (max of 141 cadence).

Any tips on approaching these? With a 1 minute interval I find I can spin up a little more slowly to the target power and float around there but if I take 10 seconds to spin up to target power for a 30 second interval, I don’t seem to hit the target. My current method is exhausting and probably messing up the intentions of the workouts by overshooting and then fading.

Rated this one as very hard but did it well enough for it to progress me but then I didn’t accept the adaptation of increasing the level of my next anaerobic workout as I felt I barely made it. Do to the repeated overshooting and over spinning.

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Couple questions to start.

  • What trainer are you using?

  • What gearing are you using?

  • Any chance you can share a link to your workouts or at the very least a screen shot that includes cadence and power?

Just keep your cadence the same. Erg will adjust. There are some issues though in Erg mode with the trainer I have.
I know that my Tacx Neo 2 in erg mode will only give me the targeted power for 27 seconds.

I think these are impossible in erg mode. Find a gear and a cadence that gives you the desired powers for the peaks and again one for the valleys and do them both in resistance mode. Feel free to dip into erg mode for the long recoveries, but get ready before the next set in your chosen gear.

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Saris H3

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This could be dependent on your trainer, or the config.
I have an old basic Elite trainer, but i have zero issue in erg mode.

Whoa my lines are always very squiggly and I do calibrate and unplug between sessions and stuff… Never seen lines like that.
I figured maybe it was just me approaching the intervals wrong but if my power lines are supposed to look like that maybe there is more going on.

My Tacx Neo 2T is very good in erg mode with any interval over 15s in a big gear (big ring) and any interval more than 5s with an easy gear (little ring). I like to run my chain line straight, so I either use a fairly big gear or a fairly small one.

I think for most trainers, using an easier gear with less fly wheel effect is very helpful for short intervals.

And gearing in use?

53 in front will have to check which cassette cog tomorrow, somewhere in the middle of the cassette where the chain line looked straightish.

Ok, that will make it harder for the trainer to make adjustment. That fast of a gear and cadence you mention is huge for the massive flywheel.

Generally speaking, trainers adjust best when in a small ring size. I get the point of using higher gearing, but know that it puts the trainer on the back foot.

For reference, here are a couple rides I could find on mobile.

I can possibly dig deeper and add more when i get to a PC tomorrow, as well as type up some tips for hitting those better.

Okay wasn’t aware of that can try it out in the little ring. Have just always big ringed it since I started in May.

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That could be an explanation of my « perfect » power curve. I always use the smallest gear that will « reach » the desired power.

I’m using power match. In ERG I will usually surge right before the resistance changes and hold on for dear life:

However I just discovered Resistance mode for the first time today. I gotta say… it felt way more natural than ERG!!! I’ll be doing this in the future for high power output days.


No, your lines are perfect because your trainer uses power smoothing when reporting power. There is no way to have that stable power, ERG or not.


I also use the Hammer H3 and have the similar problems. With the small sprocket I still have to test. In general, it seems to me but also as if the software in Android or the hardware is too sluggish or takes a long time to adjust. I drove a while ago with Zwift on a PC and also under Android, I did not have these problems. Maybe that should be checked?

For the tacx neo users here, do we have a level mode option? I switched from a kickr and only have resistance mode now. I liked level mode because resistance exponentially ramped up as opposed to the linear feel of resistance. With resistance I either am going too hard for recovery or can’t make the power targets.

Use smallest chain ring in front. For back use the fourth cassette.

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I just get up to speed and then hang on, and let the turbo adjust. I’m normally just focussed on maintaining cadence.

When I was using hybrid rollers, I always had issues maintaining leg speed in the recovery portion of microbursts, short on and off etc as per the workout instructions. I find it much easier in erg.

On my Kickr Core I’m doing these in the big ring, middle of the cassette. What works for me is to ramp up my cadence a bit about 2s before the start of the 30s intervals. Then just keep the same cadence and it’s super quick to adjust the power.
Don’t get the perfect “interval average” but when coming down you also push a bit longer the required, it evens out.