Just picked up a set of Favero Assioma DUO pedals. I did some short rides and used DC Rainmaker’s analyzer tool to compare and got some unexpected results. My trainer is consistently 5-10W higher than the pedals. Which seems wrong, with the trainer at the end of the drivetrain, it should be lower with drivetrain losses. Is this something I should be worried about? I don’t have a third power meter to see which one is off, but from what I’ve read, both seem to be reliable sources. I can use power match for TR workouts, I’m more concerned about outdoor rides.
IMO use PowerMatch and believe your pedals.
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I’m on a different opinion. Don’t user powermatch, keep doing your workouts getting power from the trainer and the pedals because, as long as you don’t change your set up and the difference is consistent there’s nothing to worry about. Remember that all powermeters have an error margin and depending on how high your power is, you can easily get 5w to 10w if the trainer is operating on the lower end and the pedals on the higher end.
I have a kickr and V3 pedals. I let the kickr control the app but i always get readings from the pedals which sometimes matches the trainer, sometimes are 3 to 5 watts off but i don’t really worry about it.
Hey @WilsonPatel,
I appreciate you reaching out on this! A 5-10 watt difference between power sources is not at all unusual. In fact, it is likely within the range of accuracy for your power sources.
Elite Direto: +/- 2.5% accuracy
Favero Assioma +/- 1% accuracy
For example, let’s say you’re producing 200 watts.
We’ll say the Diereto reads +2.5% and registers 205watts.
Your Assiomas read -1% and registers 198 watts.
Therefore, there is a 7-watt range of outputs at 200 watts that all fall within the claimed accuracy range of your trainer/power meter. This spread will increase as your power increases as well, so a 5-10 watt range falls squarely within this range.
That being said, keeping things as consistent as possible indoors and outdoors certainly has its benefits. Using PowerMatch means that your power readings both indoors and outdoors are based on your Assioma power meter, so your data will always be consistent.
I hope that clears things up a bit, let me know if you have any further questions for me!
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Welcome to hell. 
First up - Make sure your crank length is set correctly on the pedals (and within whatever head unit you connect to them). iirc they’ll default to 172.5mm.
As already mentioned here, there’s always the theoretical maximum margin of error card to play. That’s the easy one for companies who have to answer queries like this to use. It’s the path of least resistance. IMO this is used way way way WAY too often as the chances of two power meters (well, three, as the Assiuma DUO are two) all being ‘off’ in the opposite directions is pretty low.
There are a TON of variables that need to be eliminated before you know which power meter is ‘correct’… and which one is a potato, or if they’re both potatoes. Equipment being as close to perfectly clean, straight chainlines, testing protocols focusing on particular zones/intervals (overall power for a ride will almost never agree for even more reasons), data recording, etc, etc.
The Assuoma app does have a manual calibration check too. You’ll need a known/certified weight to perform that one.
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Split the difference and call it good. Life is too short to worry about a 5 or even 10 watt difference in your power meter. Pick one for TrainerRoad and stick with it.
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Just go with the pedals and use powermatch. That way you will have consistent power measurement for inside and out.
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I have the same issues with the Duo pedals and my Kickr Core. I switched to PowerMatch and all is well. One of these days I’ll do the manual calibration check on the pedals for a sanity check.
I have this issue today with the Direto XR and interesting to see GPL comment on this from 2 years ago.
I have had a Direto previously, and used a Saris. I did not have any issues for a long time, now I do.
I also have a 3rd PM in a 4iiii left crank (admittedly left only, but my Assioma Duos show I have pretty good 50/50 balance most of the time, so not concerned) .
In my experience the Duos and the 4iiii are within a Watt or 2 of each other the whole way through when using the Zwift Power Analyser. And yet the Direto XR is an even 8-9W out right through the power range.
I know from GPL’s and DCR’s testing that these trainers are much better than this. With the pedals at 1% and the trainer at 1.5%, they should not be this far out and especially when the wattage is lower. 9W at 100W. That is huge.
Why is there not the capability within Elite’s firmware to allow users to tweak their numbers if they feel confident in the results. I want to use my Direto on Zwift and TrainerRoad, not use Pedals and powermatch, as that is just a cop out. Is there ANYTHING I can do as user to bring these more in line?
Have you done a spindown on the DiretoXR? Depending on the operating temp the XR takes around 4-5mins for me to ‘warmup’ to correct watts.
Unfortunately yes I have. Multiple spin downs over several days and weeks.
Definition of insanity. Do the same thing over and over (pedal, crank and turbo calibration) and expect (hope for) a different result.
Elite have fobbed me off with the ‘within tolerance’, but your own and DCR’s tests show these percentages are never this far apart.
I’ll resurrect this thread instead of opening a new one … When riding virtual (Rouvy/Zwift), are you guys using the power meter from the pedals (Assioma in my case) or from the trainer (Direto XR)?
My Wahoo Kickr Trainer reported around 2 % higher power than my Assioma pedals. I ended up using power match to make sure the numbers are the same indoors and outdoors.
Make sure the crank length is set correctly. You can also check the right and left balance. If it is around 50 % then you know that you do not have a bad pedal because they are reporting similar values.