I’ve been noticing a trend with my workouts recently. I’m doing a lot of sweet spot and threshold work at the moment and what I’m finding is that when the interval starts it takes a while for erg mode to get up to my target power. Sometimes it takes 30 to 45 seconds to get there and for an interval section that’s 1 to 2 minutes long that’s a pretty big chunk to be under power. I’ll be holding a steady cadence and I’m just waiting for it to come up.
That said, it’s happening on the zone below what the workout is trying to target. So on a sweetspot workout the sweetspot section of the interval will be on target if not higher, but the tempo section will be lower. For threshold workouts my threshold section will be on target or higher, but my sweetspot will be lower.
It definitely feels like it’s erg mode doing it because if I spin at a higher cadence than I’m wanting to go for a section it will get up to target faster, but then I’m over doing it, like when I’m in the lower zone for an interval I like to spin in the low 90s and then in the target zone I like to spin at the mid to upper 90s, so if I really want the lower zone to get up to target power faster I can spin at a higher RPM, but then I’m higher than I want for the actual target interval.
I’ve also noticed that before the interval starts if I keep my cadence low, like in the 80s, and then as soon as it starts I spin at low 90s I’ll get to target faster, but then the power number waves a lot before getting to target.
I’m not ultra ultra concerened, I am hitting or exceeding the goal for my target power zone, but I’d like to hit the target on all of the power zones if I can
I’d say that if you are at a high cadence before the interval starts then the erg has less to do, so there should be less variety. Because the other thing is avoiding the big starting spike too, which is our natural urge to push hard when the resistance kicks up.
I’m quite lazy with it now, but as I get fitter near to peak those hard vo2 intervals appreciate a “run up”.
So get to my target cadence for the first part of the interval before the interval starts and then even if erg mode is ramping up still it will ramp up faster?
What seems to work for me and my setup is holding cadence. I figure at a fixed cadence, the trainer “knows” how much to change resistance to hit the new target and does it smoothly and relatively quickly…between 2-3 seconds. The same thing happens when the target is higher or the target is lower. I also find erg mode power regulation to be better using a moderately low gear, like a 34 ring and 17 cog. To get fancy, if I want to also change cadence significantly, I’ll shift to minimize the speed change of the flywheel. I shift to an easier gear to change to a higher cadence, and a harder gear to switch to a lower cadence.
Does this have anything to do with the type of trainer perhaps? When I first joined TR 2.5 years ago, I only used erg for quite some time. My workouts always looked like that below. Now that I don’t use erg, they look more like the OP’s. I use a wahoo kickr v6
I find that spinning the flywheel faster, with a larger chainring, small gear keeps the momentum more realistic. And, leading into a hard effort, I try to get my cadence as fast as possible while maintain control of my pedal stroke.
If I’m in the big chain ring when the power target is low, it’s way too easy to push a bit too hard when shifting my weight around, and then it takes ages for the fly wheel to slow down. Like Saddlesaur, I also find that it reacts better to resistance changes when using the small chain ring, it’s just more like climbing instead of riding on a flat road.
Another advantage to using the small chain ring is that I can stand up and overpower the trainer if the end of an interval turns out to be too hard, instead of waiting for the spiral of death.
As mentioned, that is clearly a sign of ERG Mode Power Smoothing in place. It’s the Wahoo default while others likely offer similar. It is a pretty picture heavily smoothed/averaged and not the true power as seen with that setting turned off.
Up the cadence but not to increase the power, raise the pace from about a minute out to 90-95. Then when erg cranks up the resistance it’s a relatively smaller amount you’re feeling per pedal stroke.
Try the opposite and stop pedalling just before the interval, and it will be a stupendous effort to get it moving again and show a big spike.
Although if it is going into a massive vo2 interval spinning up in the last five seconds can give you a tiny ramp up, also meaning you don’t have to mash it and overshoot the target.
Yours kinda looks like what my Elite Direto was doing before I updated it to the latest firmware
The trainer originally felt like it was searching for the power and always under then overshooting the value. After the update it felt very smooth and accurate.
I checked it against my power meter and it was reporting the same, erratic power before update to smooth power after.
Awesome thanks for all of the input everyone. I have a couple of things I’m going to try next time.
I’m on a wahoo kickr and I don’t know that I’ve ever checked to see if it needed a fimrware update I’ll check tomorrow morning because this describes exactly what I’m experiencing:
The trainer originally felt like it was searching for the power and always under then overshooting the value.
I’m also using my large chainring (I don’t remember what ratio I’m using, but it’s normally big chainring in the front and at or close to the middle in the back) and I’ve not tried using my smaller chain ring. I’ll give that a try.
I have tried getting up to my target cadence before the interval starts based on the advice from the workout text, but in those cases I was experiencing the largest “wait for erg mode to catch up” instances. Like I would get up to ~90 rpm for the first part of the interval about 30 seconds before the interval would start and sometimes it would take up to a minute after I was in the interval for the power to be on target and I was holding a steady cadence.
Here are two examples where I’m holding a pretty steady cadence but the power is waffling up and down a ton. I’m not doing anything weird on the bike as far as I know. The first gif is over a fairly small time scale, but the second one is over several minutes.
But yeah, I’m going to try it on the smaller chainring, try to get my rpm at my target speed for the first interval well before the start of the interval, check the firmware. We’ll see how it goes.
I have never seen that kind of curve on my kicker…when in erg it always follows the power target exactly unless there is a big variation over or under. I see that kind of jag if I turn off erg.
That’s because you have the ERG Mode Power Smoothing active.
It is the default and give a pretty, though partly false impression of your actual power produced.
The more jagged lines are what you will see if your turn smoothing off, even when using ERG mode.
There is likely no functional change in training effect.
The fake picture does hide natural variation and prevents people from learning if their pedaling and power production is steady (or not). That may be worthwhile for some to realize what they actually do vs the pretty picture, but it’s personal preference more than likely.
It also hides the natural variation from the activity file … which just seems wrong to me. The activity file should record what you actually did, not some heuristic smoothing to make the charts look pretty. It will reduce NP by a little for example. It will be a bigger impact for shorter intervals. But I don’t know if this inaccuracy has significant impact on anything downstream like TR workout adaptation.
RPE was “very hard”. I was able to improve my compliance from the first set to the second set, but the third set was a bit ragged. What I learnt is that you have to hold steady cadence, and let the trainer do its thing with the torque, and not let your cadence degrade while it’s doing it. The time constant on the trainer feedback loop seems pretty slow - maybe 5-10 seconds to modulate the torque. Anyway, I completed the workout successfully or so I thought.
My reward … the “did you struggle” dialog from TrainerRoad. So I guess it does have downstream consequences.
I’ll check tomorrow morning because this describes exactly what I’m experiencing:
