The importance Zero Offset Calibration Favero Assioma Pedals

Hello everyone hope you are all doing well

I just wonder what your experience is regarding the Zero Offset Calibration from The Assioma pedals. I read you shall do this before every ride is this really such a big thing? Or will it be good enough to do this once a week or when you reinstall them?

How much have you been of if you forget to calibrate them?

Reason for asking is …

Last 2-3 weeks I did a lot of outdoor riding, while I did some intensive rides well they did feel hard to me the numbers were not impressive compare to my Indoor sessions I think there I did the Trainers Powermeter.

So yesterday I did a Zero Offset and then I actually remembered that I once did take the pedals off to install one of the Washers that came with them, and not sure most likely did not calibrate them.
The ride I did yesterday was about 1h Avg Watt 203W and NP 253W IF 0.97 My TR FTP is 262W but I did think it was more like around 250 best case.
I am new to outdoor riding with a Powermeter so first, I did think the numbers are lower because it is just different to ride outdoors. Since I need to stop sometimes watch the street also there is coasting that I guess will pull the avg down.

Anyway now I am skeptical if this is too good to be true. Is there anything else I need to know about calibration? Does this make such a big difference?

The Crank length I also did check 172.5 on the Wahoo and on the Favero App and written on my Crank.

Below a picture from the ride does this make sense? A lot of Headwinds yesterday.

Thanks for sharing your opinion
Ride save

You took the pedals off and reinstalled with additional washers? Very important to do a zero offset when you change the setup

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Yes exactly what i did. So i guess chances are good that the numbers are true now. Still i think i never saw NP from 250W in all my TR Workouts, and the ride was not as brutal as many trainer sessions i did, so a bit of skeptically still there. Maybe that is the extra recovery you get outside and the better cooling? TR does not support outdoor and indoor FTP right? I read that many ppl have a higher outdoor ftp? So how you take that into account when you look at a Outdoor ride? I guess i will ride my 20 min training hill where i know my Time and then compare the power numbers. i think that will give me a good idea. right now i think the Power was off by about 15 to 20W

if your power source on the trainer is the trainer itself, it might bear some important differences.
I have a wheel on trainer, and the reading between it and the assiomas is ~15W difference.

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I calibrate before every ride on my Garmin 520 plus - in fact I get a prompt as soon as I move the pedals - it take 10s - that is good enough for me.

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Aw nuts… I just realized I didn’t do the zero offset when I swapped the Asioma onto Slick yesterday. Historically with mine I have run from 5 to 10 watts over my TR ramp test FTP when I do an outside test.

I got a +15 yesterday on the Xert FTP metric… without a zero offset so there is that.

So your numbers don’t seem way off to me… Also a zero offset is just that. It would show up on the power if you were stationary would it not? Worst case scenario would be a negative offset being data clipped at 0 on the head unit.

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I guess that would be the best. But on my wahoo i dont get a message like this i think. Can you do the calibration from the Garmin or you also have to go to the Favero app. Soon i need a pre flight check list. Once i did ride away just to realise i forgot my helm.

Older PM’s often did need to be calibrated after 10 minutes, but onboard temperature compensation means many newer PM’s (including the Assioma’s) keep their calibration.

It might not be strictly necessary, but calibrating at the start of every ride is good practice.

But you should DEFINITELY be recalibrating after removing and reinstalling your pedals (ideally after a few short sprints just to ensure everything is settled into place).


In my experience with the Duos, even moving them 2 times a week across different bikes I don’t have any issues when I don’t do the offset. As some one mentioned, it’s not a calibration but just a zero, so if something isn’t right you’d probably notice fairly quickly. Still best to do it every ride but just saying I’m lazy and forget often and don’t have issues!

On my Garmin I get a prompt and you do the calibration through the buttons on the Garmin - it just comes up with the question Calibrate? - you hit yes - it then it does it and you know it works when a “0” appears…no issues at all - occasionally I have to spin the pedal to remind the Garmin that the power meter is there!

Well that is comfortable, like this i would also calibrate it every ride or almost. Anyone know if this is also possible like this the the Wahoo devices ?

You can calibrate Assiomas using a Wahoo head unit. Hit the power button to go to the set up page, scroll down to the Assiomas, and you’ll see the option to calibrate. Takes a few seconds. Hardest part is remembering to do it.

Thanks just found it, i try to remember it, if it is only every other ride it will be good i guess.

Does it actually calibrate them or just do a zero offset? There is no calibrate option on the Assioma app itself.

i think just Zero Offset but i think on the Wahoo it is called calib. the button


I normally zero offset with my phone and the app and I’ve never had a problem with power numbers. Today I calibrated with my Elemnt for the first time. The power on my ride was massively off. My measured power was way too low. As proof my Elemnt was showing calories burned for a 4 hour ride, 115km with 2250m climbing at 1715cal. For that type of ride I’d usually be averaging about 725cal/hr. Anyone else ever noticed such discrepancies?

It may not be required but I do the zero offset through the phone app before every ride. I have noticed that my crank length seems to change between rides so this is another reason why I do it this way (other than peace of mind).

Do it every ride.

I didn’t do it before, but I started to notice weirds numbers one month. And one day, when doing a single leg drill, saw that my L/R balance wasnt 100/0 but something like 90/10 which caused an overreading.

Since then I do the zero offset calibration before every ride.

So here’s a question. I’m new to the Uno (first ever power meter) as well new to using Garmin 830. I set up the pedals as instructed, did zero offset calibration, set up the power meter in the Garmin as instructed, and used it several times w/ TR on a Elite quick motion rollers. Good readings on both the head unit and the laptop/trainer road. BUT…today I was all excited to do a ride on the road and get some initial data. Start pedaling down the street, and I get nothing in watts read out on the Garmin. Fiddled with some buttons on the Garmin, but that thing is so finicky I gave up after a few minutes and just road. Suggestions? As an aside, I absolutely hate the Garmin so far. It’s got more kinks than 50 Shades of Grey. Never functions the same day to day, has a mind of its own. Anybody have experience with the 830?

No. It works fine on my 830. Make sure you’re using ANT+ and have it paired as such.

Use your phone, connect to the Assioma and then leave it connected. Power on to the Garmin, remove the Power meter and re-pair it. It will be in ANT+ for sure since the BT is held by the phone. Disconnect the phone app, then re-configure the Assioma with the Garmin.

Also my 830 has been pretty solid, overall.