FTP mode being an a-hole

Hello fellow Pav athletes,
the big boss won’t stop giving me these “lovely” 30/15 intervals and I am really struggling recently. I usually do them indoors on the trainer and it works fine, at least as long as I am still not suffering. The problem is, I generate my power from cadence and as soon as I start to stuggle a bit and loose a bit of cadence at the end of an interval, I will try to catch up in the pause but the F**** ERG mode doesn’t adjust the resistance down quick enough and so I ride 9 of the 15 seconds pause at 250W instead of 150.
I also have that during the intervals, the ERG mode is like “so you want to do 330 and I only see 329.99, let’s double the resistance” and “you want to do 330 but you are doing 380? I don’t see why I should adjust down” (maybe slightly exaggerated but you get it)
My question is: Do you have the same problem or is it just me or is that specific to my trainer? (Elite Direto XR) Does anybody have experience with different trainers? Do you ride high or low gears during the 30/15s? Is there a trick?

1 Like

Got a WAHOO KICKR here, but perhaps the Direto XR has a similar mode. Anyway, there is something that is called “ERG smoothing”, which looks to me like another filter to avoid spikes on the power. That will help with ZWIFT over/under shooting the target. But there is still a 2 to 3 second lag, both sides, going into the 30 seconds interval and out of the 30 seconds interval.

The other thing is gearing. Using something like a 52-25 instead of a 52-17 seems to help, perhaps drop down to 36-17. Not exactly sure why this makes such a huge difference, but it does.

What also seems to help is listening to proper music. Good old rave at 140 bpm (dare I say H.P. Baxxter ?) seems to keep me on track with cadence. You might also venture into Goa Trance, good old 150 bpm :wink:

1 Like

The difference with the gearing is the flywheel running at different speeds. For me higher gears feel more like riding fast or into a headwind and lower gears feel more like climbing (or riding through a swamp to be honest).
I never really understood if Zwift does the power control in ERG mode or it just tells the trainer to set 330W and the control algorithm is in the trainer itself and where the smoothing kicks in. I will try with different settings.

1 Like

@pav never used to let me do higher intensity sessions with erg mode on!!!
In some respects it can be better as you hold it if you can and if you can’t well it’s obvious!!!

1 Like

Yup. Different flywheel speeds. But if you go from 52-17 to 36-17 your flywheel goes slower if cadence stays the same. I had expected that the momentum of a faster flywheel would compensate naturally more for power fluctuations.

I actually zero idea how ZWIFT does that. Dynamically adjust resistance and then look at the power feedback, or let the trainer handle all of that.

1 Like

Hi Chris. I do 30/15‘s on my kickr core. Cadence with the power on is typically around 100. zwift is controlling the resistance. It works no issues.

1 Like

I recognize this from my Core. As soon as you lose cadence, its hard to get back because the ERG-mode does not adapt. Had the issue with slipping out of my pedal, and trying to get back in. Though the power was not even that high (steady state sweetspot), it was impossible to get back into the rythm in a short time. I have not figured it out what it causes. A firm shout often does the trick so far :slight_smile:

1 Like

@Ultrathom I recognise this. You have to stop and then restart. I did get angry once and managed to get the brake on the trainer to slip.


Is it as simple as turning ERG mode off or running the session off of Zwift if Zwift won’t allow it?

if you got a delay in the response, like it takes 3-x sec till the trainer shift gearing down it might be related to the connection BT or ANT+ depending what u use.

I had a similar issue and I took the ANT+ dongle closer to the trainer. Works most of the time now, loosing max 3 sec if not.

5s PB :grin: I also got my trainer’s brake to slip a few times.

1 Like

That would work as long as I do well but if I am trying to do that at 180+ heart rate, gasping for air I will most likely miss the button on the iPad.

Thanks for the many answers so far, I have searched the web and watched half of YouTube and have found many sources that suggest not to use ERG mode for sessions with short intervals. I will try to do it with the gears and see how I go. The problem then is to match the power big boss ordered since Zwift doesn’t show the avg lap power but I’ll give my best.

I was on a Kickr during my last bike fit and it felt different that the Direto (even though I only did constant power there). I wish there was a place where you have all of the trainers set up to test.

That’s a great point. When I do short sessions not in erg mode I always use my Garmin display for pacing. The Zwift display just isn’t sensitive / responsive enough.

Do you upload the workout to the Garmin in advance? I’d expect it to be very stressful to press lap every 15 or 30s

I don’t upload in advance. Can’t remember if I was pressing lap or just following the instructions from zwift.