TR Sprint Effort issues

Hello, I have used 3 Trainer road 3 separate times when I feel like doing some structured work. Since I recently just sold my Road Bike. I am now back on TR for the ERG mode to help simulate my lack of gearing ratio’s.

Issue is I am doing the XC Olympic training program and the sprints so far don’t match the power. When it shows for me to do a 500-600 watt sprint I can barely turn the pedals? If I make a simulation on Zwift with the same effort ERG doesn’t cause this HUGE resistance. As in my own workout’s

I have done the XC training about 6 months ago on my road bike and had Zero issues with the same Wahoo Kickr V5 trainer. Only thing changed is the bike. I really don’t want to use Zwift plans but I might be forced to.

Any idea’s would be helpful thanks.


Is your cadence the same? It’s easier to spin up to a high power effort vs being in a lower cadence trying to hit power AND spin faster

What is the new bike and gearing in use?

How does this differ from your previous setup?

I’ve always struggled with Vo2 and ERG. I had an older wheel on trainer and for that I found best was to use resistance mode for those efforts. With a smart wheel off trainer (Hammer H2) I find I am more able to handle it so long as I start to really drive up cadence before the interval starts (start T-5s).

That said - whenever my PM disconnects - no matter where I am in my workout - the trainer power takes over and it feels like you describe

Haven’t kept up with Wahoo naming, is your V5 direct-drive or wheel on?

Also, TrainerRoad has a new PowerMatch algorithm if you happen to have a power meter on the bike.

V5 (2020) is the latest version of the top end Kickr, wheel-off.

The V5 is a direct drive.
My gearing ratio shouldn’t be a issue in ERG but I have a 32tooth front and like 52-11 rear.

As for my experience on the trainer I have used them for over 5 years. Put in over 40,000km in the last 5 years ( Zero flexing, Just saying i’ve put in hours and hours on the Zwift and Trainer Road and normally can solve most issues on my own.)

500-600w sprints should be very doable and they are in Zwift. Something is going on how TR trying to simulate a heavy load and just goes nuts.

I was really hoping to get my XC training in before the BCBIKE race, But I might be stuck on doing the Z3 - 2hr efforts as I’m fudged with the bike apocalypse and only have the XC bike now.

In the mean time I’m going to contact Wahoo and see if something could be going on, On there end.

Cheers and thanks again for any and all advice.

I’ve got a 2017 Kickr and it pre-dates your Kickr. Something is clearly wrong and you should reach out to TrainerRoad support first as they have access to all the data (TR app sending Erg commands to Kickr, and Kickr responses). Not sure how Wahoo support can help - if it works in Zwift they will simply tell you to contact TrainerRoad.

Turn off ERG power smoothing, in the Wahoo app, so you can see your real watts.

Edit: FWIW, I can never hit the numbers in ERG mode, with any trainer I’ve used. Tacx Neo 2T, Wahoo KICKR V1 and V4, Saris H3. There’s the power lag, and the eventual miss. The only way I can hit it is to use resistance mode and spool up 5 seconds earlier. So that means the sprint is longer as the ramp up is outside the interval period, as is the ramp down, though that is much faster when I cut the gears or drop to granny ring.

I think there is some technique (and possibly genetics) with being able to quickly generate huge jumps in power. If you are able to do it (inside or outside), then in my experience its possible to hit 5-20 second average power targets for sprints in Erg mode on a Kickr 2017 direct drive.

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Yup, I am able to hit those efforts on my K17 as well.

Without your shifting trick?

Depends on the specific power, but yeah, I don’t always use the shifting trick, especially for the “longer” kicks of 10+ sec.

I usually try without shifting first and only add it if I really need it.

Yeah, but it’s the trainer lag. It doesn’t matter what is done, it takes time to rise, and then it cuts out. By then, your average for the interval will miss. Especially if it’s only a 5 second interval. 10 second is better, but it will still be low because of the ramp, which happens at the start of the interval period.

I just did 470W surges, and couldn’t quite hit the marks until I start sooner so that the trainer gets a bit confused and goes up. These aren’t sprints, I do those with ERG off as the power targets don’t match. This was just 470W, so I did it in ERG.

See here, it’s offset, and dives at the end, a bit early.

Zwift behaves the same way as this. avg 2-3 sec off.

The average is a bit low, because of the diving, and that wasn’t me. As I said, I haven’t had a single trainer that behaved any different. When I turn off ERG, I extend it a bit further, and start a bit sooner, especially if it’s a sprint @ > 400% FTP. The ramp up is never instantaneous, even with a Neo 2T. It takes ~2 sec to ramp in ERG on the Neo, and longer on the KICKRs and H3.

Here’s another, a different workout. You can see the target, the actual (green line), and the power reading (yellow). Notice actual starts 1 sec before target, and the lag in power reading. Then the “actual” cuts out early, because it starts early, and the power drops.

Average power will be below the target. It may be close, but it’s below. The lag in rise, and the cut at the end.

Screen Shot 2021-04-14 at 5.44.48 PM

Edit: Zwift behaves the same way, but I think it’s 2 sec earlier in Zwift.

They don’t all look this good but here is 20-sec sprint in Erg mode (Pettit +1):

and more 20-sec Erg jobbers in Collins +1

its all timing a controlled power burst because I can dump even more power but then more oscillations during the interval.

Start going for it a couple of seconds before the interval hits and you’ll be fine.