Targeted power on erg hard to reach

Hi Zwift community,

Has somebody experienced the following? Set up: wahoo snap last generation - brand new and calibrated. Lately when performing especially Erg zwift workouts I perceive that I can’t keep up with the targeted power especially on threshold zone and above. I spin faster to bring the power up to target but it barely keeps up. Forget about doing seated low cadence efforts at 60rpm at threshold (300W). So unless I am sick or overstrained and I don’t know it :relaxed: I believe there is an issue between the trainer and Zwift. It’s driving me off the wall. The difference between the perceived effort and the power on screen can be easily 100 w and above. Any hint is highly appreciated. Thanks a million.

The mantra for ERG training is to maintain a constant RPM and let the trainer adjust. Do not adjust RPM. This can take a few seconds depending on trainer. Not sure how good the Snap is for ERG…I used to have one but never did ERG.

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Yep, by increasing RPM you are making the trainer reduce resistance. You wanted increased resistance so you need to keep the RPM constant and let the trainer catch up. It’s counter-intuitive at first since it’s the opposite to how things work outdoors.

wheel-on trainers are notoriously inaccurate even when calibrated. especially if ur taking the bike on and off the trainer a lot. so that could explain the difference in feel.

barring that, if you want lower cadence you can still change in to a harder gear with ERG mode on.
but workouts will have a set target cadence x power and the trainer will continually adjust the resistance to get you to that point (but give it some time).

if you think there’s issues with the trainer or w/e go do a free ride outside of a workout and see if the power numbers feel right in that or better yet get holf of a secondary power meter to troubleshoot.

but yea, threshold is supposed to feel hard, especially if your FTP is set up correctly, if you didn’t have a rest day the day before, then don’t be surprised if you blow up.