Ramp-up not working properly

Hi all,

I am using a Tacx Neo 2T Trainer with Bluetooth connected via the Companion App. Zwift is running on PC.

When doing workouts with ramp-up sections I noticed that the ERG target power is updated very infrequently with update intervals > 10 seconds. Also, the power changes are VERY coarse.

Just to make clear the order of magnitude (no exact numbers):
There was a 30s ramp-up from 100% FTP to 150% FTP and the Power steppings were like 100%(0s), 115%(10s), 130%(20s) never reaching full target power.

Using the Kickr Core some weeks ago, the updates occured in steps of 5W (not 30W) and much more frequently.

I think, there might be a bug in the power update interpolation for the ramp ups which might be called too infrequently.

Did anyone experience the same with different trainers?

That seem strange, I did a workout this morning and if I look at my data it had a linear ramp.

image

Few weeks ago, workouts begun to round by 5 watts.
Not only for display purpose, but ERG mode really set wattage rounded by 5 watts.
We need to adjust workout by 1 watt, not 5.
Especially important for kids. It’s huge differense between 40 and 45 watts.

From my experienced the rounding precision has been 5W for a long time. I don’t see the point, too, why it needs to be that coarse.

see my post above

What trainers do you use?

This is a graph generated from one of these workouts (Dec 18 th, Tacx Neo 2T) which had three repetitions of:

185W for 5 min
30s ramp up from 194W to 291W
95W for 2:30 min

The ramp up section is marked blue. As you can see, Zwift jumped to 195W and then directly to around 240W until the end of the ramp up. It seems that the power is updated every 15s. I saw that the trainer followed the power profile shown/set by Zwift. I see no reason why this should be an issue with the trainer.

Gerrie, the update interval of 15s might be the reason why your longer ramp-up section looks linear.

How long is your ramp in the workout?

It’s 30s long.
There are plenty of these zone 5 ramp-ups in the “Build me up” training program.

Tacx neo 2T and Wahoo Kickr. Both of them round workouts by 5 watts for ramp and fixed intervals.
Strava power graph 20.12.2021. All steps rounded by 5 watts. 20,25,30,35,40W.
Main part intervals 35/40W


Workout main part have to be 35/38W

This is a kid’s workout.

Next strava snapshot 03.11.2021. No rounding.

what do you mean by kid’s workout.

My ramp on the Saris H3 look like the top ramp. nice and smooth.

Hi Gerrie, he meant that this workout was designed to be done by kids for which the 5W rounding steps are already pretty coarse.

I found your workout you mentioned on Zwift. It has a ramp up from 95W to 230W over 5 mins. If the power update interval is indeed around 15s, you should have had steps of 7W. So the ramp-up is long enough to look smooth.

I did some testing with a custom workout. It has 3 ramp-ups from 25% to 75%( within 30s, 1min and 2 mins. I ran them wit/without the companion app on PC and Android.

It was the same result on each try:

  1. The power was updated every 15s
  2. The power was rounded to the next multiple of 5W

It resulted in the following power levels:
30s ramp: 0s: 50W, 15s: 100W
1min ramp: 0s: 50W, 15s: 75W, 30s: 100W, 45s: 125W
2min ramp: 0s: 50W, 15s: 60W, 30s: 75W, 45s: 85W, 60s: 100W, 75s: 110W, 90s: 125W, 105s: 135W

The power ramping in Zwift doesn’t update the power frequently enough. An update interval of <= 5s and power precision < 5W would make more sense. I don’t even get the point why power is not rounded to 1W increments.

Gerrie, can you confirm that your power is updated more frequently than 15s?

Hi @J_Unis_Berlin

I just did the same test as the one you did and I can confirm Zwift update the numbers every 15seconds. I never noticed it probably because my ramps are long and only in the start of a workout.

Kid’s workout means that my 6 year old son is riding.
His FTP is around 50watts.
5 watts steps are to big for little kids.

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Thanks for your clarification.

As i can see.

  1. 15s ramp update has always been.
  2. 5W power rounding begans Approximately month ago.