Why does the TR software bomb out 2 seconds before the end of an interval?

As the title suggests.
I’ve been training on a trainer in erg mode and can’t understand why the resistance would drop off 2 seconds before the end of the intervals? Is there another thread on this, or a podcast that discusses the reasoning behind this feature?

It makes sense to start them 2 seconds early.

As a horrible politician once said ‘Please explain’!

PS. Another horrible outdoor ride on a local trail over the weekend. I only managed 13 PR’s on Strava this time. Definately down to the TR software wussing out 2 seconds early!
(It’s taken awhile,but the SPB is doing its thing for sure ;).

If you notice the interval starts 2 seconds earlier as well. Actually I think it is 3 seconds at each end.
That is intentional to allow you to ramp up

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Thumbs up John. It was a little tongue in cheek.

I love the early ramp. Really works well to let you get upto the right power.

Please let me switch off the early resistance drop.
It sucks on the shorter intervals. It sucks on the longer ones as well.
The way my mind works, I focus on switching off the discomfort and remembering the joy that recovery intervals bring. Give me the resistance drop at 0 seconds.

As it stands, I find myself pushing the hardest to make bank when the power suddenly vanishes.
TR drops the mic and is out of there.
At this point I’m smacking on my pedal strokes as the machine and I play catch up.

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Totally agree with this too. I love the 1-2 second early ramp up, the 2 second early drop sucks.

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I agree too. It just feels weird, psychologically, that the power drops, before the interval is over

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Thats odd, its been reported by TR that power smoothing only changes what you see in the live display, the “366” watt current power in the picture below:

Power smoothing does NOT change how TR app controls erg mode. It does not change the power graph. It only changes the live power being displayed in upper right of TR app.

I’ve used 0 sec and 10 sec smoothing, and with Kickr 2017 and PowerMatch the smoothing setting has not changed the timing of resistance changes at start or end of an interval.

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Are you confusing:

  1. Power Smoothing
  2. TR sending the trainer adjustment instruction early

The two are not related in any way.

on my Kickr 2017 (wheel off, direct drive) it starts 1 second early and ends 1 second early. So the entire interval is shifted 1 second early.

For me that makes the actual line up pretty well with target, here are a couple 60 second intervals from Freel (anaerobic) last night:
53%20AM

looks good, seems like that 1 second shift is working? I’m not that hung up on having actual power exactly match the blue target.

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Yup, I confirm that it’s a one second difference for my Hammer and Kickr trainers. I see similar results to Brian’s above.

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That’s interesting that you call it at 1 seconds. I swear my Kickr kills the resistance 2 seconds out.
It actually feels like it happens ever so slightly before the timer shows 2 seconds remaining.

Anywho, I don’t really think it makes much of a difference to the workout. It would be nice if it didn’t drop off early.
The funny thing is that I’m finding the workouts easier on the erg trainer, compared to the basic fluid trainer. On the fluid trainer I’d ramp up earlier and often overshoot the intervals while trying to keep the power on target.

I’m sure mine drops off as soon as thre beeps start, maybe 2.5 - 3 seconds at the end of an interval. I like it. It’s like a carrot approach to an interval well done

For these shorter intervals, you can also switch to Standard or Resistance mode if you don’t want to deal with the ERG ramps on either end. Then it’ll be up to you to shift gears and change cadence to hit targets, much like out on the road.

It could be as much a 2 seconds early, but what I see on my ride reviews in the data is one second.

The theory overall is that no matter how early it comes on/off, the overall interval length will be the same. Start 2 seconds early, then you end 2 seconds early.

As to ERG being easier, that varies on when and how you look at the comparison to manual trainers. Yes, you are more likely to hit the “right” power target numbers with ERG and not over or undershoot in general.

But, there is no real “relief” if you slack off on the cadence a bit (like some do on manual). In fact, that act will result in increased resistance with lower cadence, and often leads to the death spiral if you don’t push extra hard to get back to a better cadence.

So, pros/cons in all cases and there are things that are different and should be understood to get the most from any setup.

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Hi Larry,
I really like the little toggle at the bottom of the desktop app for this.

Now that I have an erg trainer I’d prefer to simply let the unit do the thinking for me. Having the resistance drop before the end of the interval just seems odd to me.

You forgot to mention what happens when you get signal interference and the erg trainer doesn’t drop the resistance. OMG!
It happened to me the other day at the end of a short sprint. I was expecting the usual drop off and instead the Kickr made me hold power for an extra 5-10 seconds.
Fun and games.

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Yup, I have had the odd “never-ending” interval. They suck, in a way, but now I came to a different take on them. I look at them as “random” intervals, kinda like outside when you might expect (or want) someone to let up and go easier, but they keep pushing hard and hurting you. I see that as a mental test to go above and beyond the “planned” interval.

That heads of into a separate topic that I have strong feelings about, but don’t want to derail here. In short, it’s about doing intervals “blind” so you don’t know exactly when they will end. It’s an effort to bring back the uncertainty we often have in mass-start events and trying to hold pace with a group or another rider.

If I ride a short interval in erg mode and ride it at the target power when I finish (and the power drops a few seconds before the end) I am always at a negative value from the target power. It’s frustrating and I’m not sure what I can do to actually “pass” the interval in erg mode. Am I actually -60 watts when I do a 10 second sprint at 150% and I hold the target power for the duration but drop for the last 3 seconds?

I have posted on this in 2 other recent threads. For now, know that you are likely not missing the target by as much as you think. Ignore the numeric table summary, and look at the graph of the individual interval.

I will link in the more detailed answers I have done.

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You don’t need to be frustrated if you focusing on breathing and aerobic benefits, which is the reason for doing micro-bursts.

Spanish Needle -3 which has 12 second micro-bursts, here is a recent workout zoomed into the middle of 2nd set:
20%20PM

I’m sure I could cherry pick some “failed power” intervals, but that isn’t the point.

The point is the red heart rate line. In other words, power targets are NOT the goal of micro-burst workouts!!! This is the point of micro-bursts:

Focus your attention on the red HR line, because the point of these workouts is accumulating a lot of “heavy breathing” time:

This results in improvements in aerobic capacity due to the high oxygen uptake necessary to sustain these workloads and the short rests that keep your breathing and HR from dropping very far between bursts.

Improvements in aerobic power come due to the repetition of high-output efforts and improvements in neuromuscular efficiency occur due to the necessarily rapid recruitment of muscle fibers each time the intensity shoots upward.

For micro-bursts like Spanish Needle, the game is focusing on elevated HR and heavy breathing (not power targets). This was covered in a recent podcast episode.

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