Fellow Zwifters, this thread had me curious so I’ve reviewed so far three E-Sport cycling platforms racing rules & regulations documents. The common rule observed is that trainer should be primary source, direct-drive recommended and power meter as secondary recording device. Below is from pg. 5 from Ver 1.0.7 ZADA doc:
I think the rules encouraging dual recording is very good.
Just curious, would a wheel on trainer be barred even if it was reading within 2% of the powermeter.
The Assiomos are reliable and correctly calibrated.
The Zwift Hub doesn’t claim to be especially reliable and has known underreporting issues once warm above 300w.
Here is a 20 minute TT effort I did with constant cadence and no trace of any sticky watts, 2 months ago average 341 watts.
That’s my second highest 20 minute effort, only 7 watts behind my best (which did involve some sticky watts)
The 341 watts was 2 months ago, the 348 last week.
In those 2 months, training has been showing improvements.
So, this idea that you get a massive advantage from this, and artificially inflate your numbers is actually debatable, unless you do it deliberately over and over again.
What are you looking for with this post? For everybody to tell you that you are right to use assiomas as primary? We won’t.
But you can just go on as previoulsy, nobody cares.
That’s fine, I will continue as previous and the ‘use your less accurate trainer because sticky watts isn’t possible’ brigade also have opinions that I don’t care about.
You’ll care about your power metering choice when you are DQed from future races. If you’re not going to race then there’s no need to change what you are doing. If you are DQed then at least you will know why and you won’t need to ask on this forum - and go through these arguments - again.
Yeah, I guess that’s just a risk you’re taking. I can foresee some sort of automated DQ mechanism being introduced to tackle the genuine sticky-watts issue and you might get caught up in it.
You say your Asiomas are correct.
You say your trainer reads low by a substantial amount.
I’m reminded of the old saying, “Never go to see with two chronometers. Take one or three.”
In other words, having 2 power meters that read differently, you’ll never know which is more correct.
If you can’t incorporate a third power meter ( spider, crank, etc ), you will never really know which one is more correct.
It’s best to just go with one and live with it.
You’ve been flagged, that’s the first step. @Dan_Kothlow is right - if you want to be sure, you should check with another PM. What if Assiomas are overrreading when warm?
I’m not trying to have a go at you.
Assioma pedals are very good and I have them
Many people do.
They work great but they do have a performance envelope.
If you stay within said envelope, they are good.
How do you know your trainer is off?
Dual recording is the only way to know and making the results public is how debate is avoided.
My trainer can be off but if I calibrate with my pedals, my power readings are usually within 2%.
Is that accurate?
I’m new to dual recording too and most people just don’t do it.
Rather than blanket statements like “X trainer is inaccurate”, can we say any trainer with a repeatable accuracy of 4% (or 2 or whatever) is acceptable.
Of course you still can cheat but have matching Numbers in your dual records but it is harder.
But when you are not cheating and just want to check if your trainer or your powermeter are accurate, when you usually have a cohérent dual record, if it starts to show a difference you know something is wrong.
The Kinetic InRide is not measuring actual power, it’s doing onboard calculations of power based on flywheel speed.
That’s why you’re seeing those bigger discrepancies as you go farther up the power curve. Kinetic was kind of shady on this in marketing material, like Decathlon is with their D100. It’s really just calculated power (like ZPower) being computed internally and being reported to Zwift as actual power.
It’s measuring the force it takes to push oil through a fixed orfice.
My pedals measure the force it takes to deflect a metal bar.
Both are surrogate estimates of force.
There is a delay in the application of the force and the resultant acceleration.
Just like in drag racing.
The engine produces 2000 + horsepower but the car sill has to accelerate.
The Kinetic seems to be pretty consistent but under estimates the short duration efforts.
I guess it is what it is.
The term accuracy may be defined several ways.
While many have posted dual recording of instantaneous power from races, this is the first dual recorded critical power curve that I have seen.
cheers
