New powermeter, unusually high power. Am I doing something wrong?

Just got my new Favero Assioma Duo pedals. Just finished the installation, activation, calibration, etc.

Then I tested it using TR (the Power Training Ridethrough workout), and recording the power numbers of my Tacx Flow smart trainer on my fenix 6.

To my surprise, the Assioma power numbers are about 20-30W HIGHER then the trainers power numbers. The average power of the WO was 184W in the Assiomas, and 166W on the Tacx Flow Trainer.

I tried checking the settings, if I had something badly configured, even changed the crank lenght to see if it had any impact, but no, it keeps reading much higher.

Am I doing something wrong?

20-30W sounds totally plausible. Was the power relationship between the two linear?

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they ought to be higher, based on drivetrain loss.

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Yes it was.

That makes sense, but I’ve seen on the forum that usually the Tacx Vortex and Flow have higher numbers than the “dedicated” PM (sime say 10-20% higher). I find it very strange that I’m finding 20W higher power on the Assiomas.

Thats pretty plausible with a wheel on trainer. Just believe the new number and move on with life.


I’m not mentally ready to have my FTP go up by 20W just by changing powermeters :grimacing:

I’ve been checking everything, and I think I did everything perfectly. Installed correctly, activated the pedals using the app, calibrated/zero offset, crank lenght set correctly (170 in my allez sport).

Anyone has any experience like this going from a tacx flow to assiomas?


Sounds plausible to me too.

How careful are you calibrating the flow? 15min warm up every time?

How well is your drivetrain running? 20w seems excessive for drivetrain loss but even if it was clean it would sap 5w or so.

Then the flow is only claimed accurate to 5% so that’s another 10w.

As long as your L/R balance numbers are good from the faveros I’d trust the numbers they give you.

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I usually calibrate the Flow right away, before the workout and without warm-up. Maybe that’s the issue.

As for the drivetrain, I don’t ride outside much, so its pretty clean, but I guess I could try to clean it to check if there’s any difference due to the drivetrains.

Thanks for the tips. I’m going to do a ramp test tomorrow, and I don’t know if I should record both power numbers. It will make me crazy compare the two :man_facepalming:

Same thing happened to me when I switched from Wahoo Kickr Snap to Favero Assiomas. 10/15% increase in power readings. My Assiomas agreed with a Computrainer, so I trust the readings.

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Yes. It’s a known law of the universe that you don’t question your power meter for reading too high. Ever.


Okay then, seems like I have to trust them :man_shrugging:

After 6 weeks of build and this new power meter, my new FTP is going to go through the roof :sweat_smile:

For Tacx Flow Trainer, not much surprising :slight_smile:

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But, but, but…all that matters is that your power meter is consistent, right? Who cares if is actually correct, that’s only something true nerds worry about.


I guess I’m a nerd :nerd_face:

I see no reason to doubt the faveros in your situation.

The beauty of having the DUOs is that they are essentially two independant power meters - if one was wrong you would know about it in the balance data.

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Hi, I have the same combination (I think? Tacx Flow Smart). At the beginning, when the trainer and everything is cold, it reads around 25W lower than the Assioma Duo. But after the warmup and into the first longer TR interval, they match quite good (2W!). Either you just rely on the Assioma, or you always calibrate the Tacx Flow Smart after let’s say 15min. If the Tacx Flow Smart has been calibrated “hot” once, it keeps the good calibration in “hot” conditions. But at every start of a workout it will have too little resistance.

I thing spending your money on the Assiomas and a cheaper Trainer is smarter than going the Direct Drive Route for the same or even more money.

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I’ve noticed the same with my Flow Smart. Once warmed up, it’s within a few Watts of what my Assioma Duos are indicating.

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Yeah, today I did a ramp test, and after it warmed up, the results matched pretty much what I was expecting. I didn’t record them simultainusly, but the perceived exertion matched pretty much what I was used to with the Flow power numbers.

I guess the difference is only at the beginning when the Flow is “cold”.

I’m just happy the Assiomas are reading correctly, I thought I might I done something wrong with the setup.

Thanks everyone :+1:

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As you should be.

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That’s interesting, because it is usually the other way 'round, with heat causing resistance to fade. Maybe they try to compensate electronically and have overshot the mark?