I bought the trainer in December 2021. I have ridden it for 814 hours 27899km data from Zwift. The trainer works without any complaints. Calibration number is 6498. May 2025 offset was 6493. Then for the first time I tightened the belt and set it to 6498. Now in August I bought Favero Assioma MX-1 Pedals. power meter only in the left pedal. The result is that the pedal reads lower watts than the Trainer. In the beginning of ride I am on free ride for 15 minutes after that I stop and go in Elite App to calibrate trainer. Offset is 6496. Then I start my workout mode with 5:30 min 190 watts on 90 cadence then 30 second 190 watts but out of saddle with 60-70 cadence. Erg is On The pedal reads 169 watts, the trainer 190 watts. thatās 21 watts less. In general, the pedals should read a little more watts than the trainer.What could be the reason for the trainer reading more watts? This is a comparison between the pedals and the trainer. Firmware 87 Hardware Revision 21
The pedals are hand-tightened, set to 170mm, and calibrated before riding. I also use shimano sm-sh51 parts that I took from the pedal kit. I havenāt used them on my other bikes for now, Iāve only used them on the trainer.
zwiftpower com/analysis.php?set_id=501848
You mention that the pedals are hand-tightened, but itās important that they are torqued to the manufacturer-recommended value otherwise you may get incorrect power readings.
Separately, you say that you have just one power pedal, so on one side. Therefore if your power is naturally lower on that side (and everyone has some sort of imbalance), then when the power meter simply doubles that power for reporting purposes then it will be under-reporting.
I know about that. But even if the trainer measures 2% more and the pedal is 1% less and I ride with 46/54% the numbers still donāt add up.At 190 watts 2% is 3.8 watts = 186.2 watts At 168 watts with -1% difference in accuracy it is 1.68 watts = 166.32 watts. If the left leg does 4% less than the right 166/2 is 83 watts then the right leg would do 83+4%= 86.32 *2=172 watts. This is again -14 watts less.Also the Pedal should show do more watts than the trainer because (chatgpt):
1. Measurement Location Matters
The Favero Assioma MX-1 pedals measure power at the pedal, which is the closest point to where you apply force with your legs.
A trainer (like the Elite Direto XR-T or similar) measures power at the rear hub or flywheel, which is after the drivetrain.
Because of this difference, the pedals capture your full output before drivetrain losses, while the trainer sees a slightly reduced value after those losses.
2. Drivetrain Losses
You typically lose about 2% to 4% of your power between the pedals and the rear wheel due to friction in the chain, cassette, pulleys, bottom bracket bearings, etc.
So, if youāre pushing 200 watts at the pedals, only about 192ā196 watts may reach the rear hub.
That means:
Favero pedals should show slightly higher power than the trainer, assuming both are correctly calibrated.
3. So Favero > Trainer Is Normal
If you see:
Favero pedals: 200W
Trainer: 190ā196W
ā That is normal and expected.
If Your Trainer Shows More Power Than Faveroā¦
Then something may be wrong:
So this is a commonly mentioned notion. But I always thought that the trainer manufacturers know all of this, so of course they would likely build this correction into their trainers.
Sounds like youāre going to need to borrow a third power meter of some sort to figure out which is more likely correct.
So what about the torque for your pedals? Hand tightening isnāt going to give you accuracy.
Itās not 4% less in a 46/54 split. If you pedal is reading 169 watts then itās measuring 169/2 = 84.5 watts from your left leg. With 46/54 split then your right leg is doing 99.2 watts, for a total of 183.7 watts. Thatās only 6.3 watts off from your trainerās reading.
But never mind the maths.
Yes, the trainer should read lower than your pedals, but as I said, not properly torquing your pedal could easily account for that.
ok i have calculated it wrong. It turns out that if you measure the left leg at 46% and the right leg at 54%, you will measure 183.8 watts, which is closer to 190 watts. And if you multiply the right leg, you will get 198.6 watts. Chatgpt:
Problem:
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You have 169 W reported from a left-only power meter (e.g., a Favero Assioma UNO).
-
That means the pedal measures 84.5 W (left leg) and doubles it:
84.5Ć2=169 W84.5 \times 2 = 169 \, \text{W}84.5Ć2=169W
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You assume your left leg contributes 46%, and right leg 54% of total power.
-
Now you want to know:
What would the right-side power meter show, if it measured the right leg and doubled it?
Correct Logic:
Since the left leg = 84.5 W = 46%,
then the right leg is proportionally:
Right leg W=84.5Ć5446=99.3 W\text{Right leg W} = 84.5 \times \frac{54}{46} = \boxed{99.3\,W}Right leg W=84.5Ć4654ā=99.3Wā
Thatās because 54% is more than 46% by a factor of 54/46 ā 1.1739.
Final Answer:
A right-only power meter would measure 99.3 W and report:
198.6 W\boxed{198.6\,W}198.6Wā
Comparison Table:
| Power meter | Measures | Shows (after doubling) |
|---|---|---|
| Left-only (46%) | 84.5 W | 169.0 W |
| Right-only (54%) | 99.3 W | 198.6 W |
Summary:
-
The difference comes purely from left-right leg imbalance.
-
Using a one-sided power meter on your weaker leg will under-report your true power.
-
In this case:
Right leg meter would show 29.6 W more than left.
I watched a video of Shane Miller GPLAMA youtu be/9uNTIHOb_0Y?si=IxqQn8noacq79lAF&t=632
and he doesnāt use a torque wrench despite his reviews of pedals with power meters. and his data is still accurate 186w for pedals and 183w for trainer. He uses the same Direto XR trainer with MX-2 pedals dual power meter. I have 3 torque wrenches but I donāt have a 15mm wrench attachment. My wrenches only work with hexes. I have ordered an attachment but it will come in 1 month.
Do you know that you have a Left / Right imbalance or were those numbers just a hypothetical thought experiment?
54/46 seems large.
I was amazed at how balanced my legs were, 50/50 or 49/51.
A friend of mine with a known remote leg injury was 48/52 or so.
Interesting, he found the increased Q angle actually relieved ankle/foot pain he experienced.
I would suspect something more is going on.
Iām just guessing and giving an example of the worst case scenario. I have no leg injuries and I think my legs are balanced and if there is any difference it will be 1-2% maximum. As far as I know if you spin at a high cadence 90 revolutions harder one leg can dominate the other. At a lower cadence it is possible to make a bigger mistake. I also talked to a cyclist who told me that in zone 2 there is a bigger imbalance but when he rides in the upper zones his leg balance is 50-50%
Maybe he has a very good feel for what the accurate torque feels like? Can you guarantee that you are torqueing the pedals the same as he is?
I thought the same - until I got a power meter with L/R balance. Had never an injury, but being an old man I have 50/50 some days, mostly 51/49 L/T, 53/47 L/R max. More difference on longer rides.
The pedal is tightened using the method of stepping on an electric scale and tightening the pedal until it shows minus 20-23kg of weight. This is for a wrench with a size of 18cm from the center of the pedal to where it is pressed. This corresponds to 35-40NM. I have also added 1 washer from the Favero set. I did 4 tests. test 1 is in my whoosh, test 2 in Zwift. Test 3 and 4 are with another bike that has a Sigey Spider power meter. Also he say i have 49/51 on L/R on 90 cadance and 48/52 on 60 Cadance. Bellow is data with text: all links for zwiftpower analysis are in youtube video description. The test is Workout with 1 min on 130w, 160w, 190w, 210w, 240w, 270w and 300w.
Test 1 Elite Direto XR vs Favero Assioma MX-1 in MyWhoosh in workout mode with ERG on
30 Seconds 302 watts 285 watts(-5.96%)
1 Minuteā¦ 299 watts 279 watts(-7.17%)
5 Minutesā¦ 229 watts 208 watts(-10.1%)
Test 2 Elite Direto XR vs Favero Assioma MX-1 in Zwift in workout mode with ERG on
30 Seconds 301 watts 280 watts(-7.5% )
1 Minuteā¦ 299 watts 276 watts(-8.33%)
5 Minutesā¦ 241 watts 220 watts(-9.55%)
Test 3 Elite Direto XR vs Favero Assioma MX-1 vs Sigeyi AXO Sram 3-5-110 90 Cadance
30 Seconds 300 watts 273 watts(-9.89% ) 291 watts(-3.09%)
1 Minuteā¦ 299 watts 270 watts(-10.74%) 290 watts(-3.1%)
5 Minutesā¦ 241 watts 212 watts(-13.68%) 231 watts(-4.33%)
Sigeyi 49% L / 51% R L/R Balance
Test 4 Elite Direto XR vs Favero Assioma MX-1 vs Sigeyi AXO Sram 3-5-110 60 Cadance
30 Seconds 302 watts 284 watts(-6.34% ) 293 watts(-3.07%)
1 Minuteā¦ 299 watts 272 watts(-9.93% ) 290 watts(-3.1%)
5 Minutesā¦ 241 watts 219 watts(-10.05%) 233 watts(-3.43%)
Sigeyi 48% L / 52% R L/R Balance
https:// www.youtube .com/watch?v=vvNdYh49kDA
I also have a mountain bike with an Xcadey Gen1 power meter, but I donāt bother installing it because the last time I compared it with the Direto XR, it was reading 20ā40 W higher than the trainer. Back then, I assumed the trainer was more accurate, so I set Xcadey to 86% of its default power (meaning it now reads 14% lower).
However, now that I also have a Favero Assioma power meter, Iāve noticed it reads 12% lower than the Direto XR. Only the Sigey power meter is about 3.5% lower than the trainer.
Iāve also bought a brand-new belt for the Direto XR. When I have time, Iāll replace the current 3ā4 year old belt and test whether thereās any difference between the new and the used one.
Are you regularly calibrating your Direto? If uncalibrated, over time, it will start to over-report wattage, by up to ~15% vs a calibrated power meter.
Itās strange that Elite hide the calibration function in their app, and until recently, didnāt emphasize that the trainer needed to be regularly calibrated - about every two weeks or so.
And yet, dumb trainers are considered too inaccurate for racing even though I can repeatedly demonstrate my trainer is reporting within 2% of my Assioma pedals.
The trainer difficulty is zero by default but the race require a TD of 30% and many sources claim TD doesnāt matter.
I donāt want to take this thread off topic.
Just a comment and I hope this thread will lead to use of standardized equipment performance and not standardized equipment.
Itās not enough to say āeveryone should use the same equipmentā.
We need to say everyone needs the same level of verification regardless of equipment
Iād argue having that close of a balance is incredible.
Iām generally 42/58 up to 44/56
I canāt speak for the Elite, but my Pro RS-2ās seem close enough for use case to my KickrbikeV1
I did not use a torque wrench; nor did I on my new Magene P515 and it seems to be somewhat accurate
I will say, I have had issues with my PRO RS-2ās changing crank lengths settings. Things for the most part seem to match within +/- 2% on 5+ minutes until it forgets what crank length Iām on. Sprints though seem to range a little more wildly up to +/- 4%
Honestly for me itās been more of a struggle with the Assiomas, it seems like things are āfineā if I donāt touch them. As soon as I open the app, things go weird.
Only drive side of mine has the washer to clear the kickrbikeās plastics.
For my tests when I do a dual record and put it up and have to hide it because itās all messed up, I have a 4 minute ERG step.
Only because itās quick and easy.
For anyone on Garmin, check out ANT+ Power Meter on the connectIQ store, thatās what this picture here is, a in-device dual recording.
It allows you to record two PMs at once, one has to be ANT+
Some days even with a Kickrbike I just get better readings than others.
Wrong crank length however:
Last little edit, to speak about the crank length thing.
Iām having to set it in the Assioma app, and then close it. It seems as though whenever I open the app up again and connect it to the pedals, it resets the crank length.
Clearly a bug, but figured itās worth mentioning.
On my watch, which I use to record all of this one, I have to keep them at 172.5. If I change them, I get what looks like the last image.
If I set them in the watch, it then breaks the app and sets them to a really screwed up number.
My assumption is the math internally uses crank length to adjust power by a multiplication factor; so if you have 160mm set in the app, and 160mm set on your device, itās now treating them as if theyāre 140mm (a gross guess). At least, since receiving my Pro RS-2s, this is what Iāve had to figure out.
L/R 42/58ā¦. I would expect that in a case of leg or spine issue.
We are discussing from our own experience.
As I said, Iām about 50/50 and just assumed most would be the same unless there was an injury.
I never used a torque wrench either.
I canāt even find one! Magene with the PES everywhere instructions wise I could find made it seem like those BB44ās with the square hole are common. I have yet to find one!
My pedal wrench I got recently as well, same thing; no square holes.
And Iām a gearheadā¦ itās so frustrating 
As for my balance weāll see if it evens out over time, things have felt wrong for me since I went to shorter crank arms on all of my bikes earlier this year; I have no idea if Iāve always been this misbalanced or not.
What I donāt love is that things like my spider Magene reports L/R but, itās not real, but it shows near 50/50ā¦ no idea why power meter manufacturers designed them that way, but here we are.
assioma suggest, actually recommend, setting the crank length on the head unit rather than the app