TrainerRoad - Can we get a final answer on smart trainer calibration with PowerMatch?

@larry, @Nate_Pearson, @Bryce, et. al - Can we get a definitive statement on whether or not a smart trainer needs to be calibrated (spin down) when using PowerMatch? There are numerous threads right now discussing this and your responses are inconsistent. This seems to be true regarding TR tech support responses as well. In the past 24 hours alone @larry and @Nate_Pearson have contradicted each other in separate threads.

How about answer it here then forward the answer to everyone at TR for future reference?


I’m keen to see their reply, however since I’m measuring power from my power meter and not the trainer, the power is the power is the power. I calibrate my Quarq, I pedal to interval requirements, and the power displayed on TR is identical to the power recorded by my Garmin because the power is the power is the power.

The calibration of trainer is moot as far as accuracy of power. Perhaps it may respond to changes in the workout when in ERG mode, etc, I have no idea. But calibrating the trainer when I’m measuring and using power from my power meter doesn’t make sense.

Calibrate your PM and pedal your bike is my take. I’d love to hear different.


These points have been brought up numerous times, however there are still multiple recommendations/reminders by people who actually work at TR saying to calibrate the trainer too.

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Calibrate both. You don’t want to be using a trainer that is hitting its floor or ceiling coz it’s so far out of whack (technical term). :nerd_face:

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If you’re using powermatch you don’t need to calibrate your trainer. That’s it.

I tend to calibrate my trainer whenever i move it or if there is a large temperature difference. This is only to make sure power match has to do less work and can hopefully hold me closer.

Ultimately as long as your PM is calibrated youre all good.

You need to do the occasional spindown on your smart trainer. Powermatch from my experience works best when the trainer and power meter match each other closely. The more apart they are in accuracy / watts then the longer the smart trainer will take to settle to target power. This particularly applies to interval workouts where there is a sudden change in power target. The bigger the difference the longer the settling down duration.

Your power meter still requires a regular i.e. daily zero offset if it has one.

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I calibrated my smart trainer when I got it. Don’t know if I’ll ever do it again unless there’s a long layoff. Can’t figure out why I would need to if I’m using PM and it’s working fine.

Using a PM that doesn’t require any sort of intervention is nice.

The InfoCrank® uses a Wheatstone Bridge to measure Tangential Force. This means there is no calibration necessary, there’s no re-zeroing and it operates accurately at any temperature, second by second, day by day and year by year. It’s also fully waterproof.

There are no magnets, accelerometers or gyros required to measure cadence with 100% accuracy.

Tacx Neo, for instance, does not require calibration. Just make sure you have the latest firmware on it.

You still have to do a spindown. Same as Kickr, no calibration required, but spindown is. A PM that doesn’t require zeroing every ride is nice.

Um, you have confused me.

Spindown = Calibration
(for a smart trainer at least)

Everything I have ever seen says the Neo does not require calibration, or spindown, or anything else you want to call it.

And nearly every real power meter requires a zero offset (incorrectly called calibration in this instance). There is a crank based one that claims no need to zero, bu all others I know about require a zero offset.


I’m an extreme outlier on the curve of calibrations…

I calibrate my trainer only when I have physically moved it. Swapping bikes? No calibration

I really only calibrate my on bike power meters if something has changed. If I’ve swapped between bikes I calibrate, changed batteries I calibrate, taken from inside to outside I calibrate. I don’t calibrate if it’s just been sitting on the bike on the trainer and nothing has really changed.

The modern PMs all tell you to calibrate regularly and stay on top of it - but they also have temperature adjustments and auto zero built into them. I think in most situations, more the majority of rides, you don’t need a calibration beforehand

But…like I said at the start - I’m an outlier on this one

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You can’t even do a spindown or calibration on a Neo


@larry @Bryce Be aware.

There are two parts to this.

  1. With today’s PowerMatch, doing a spin down calibration on your trainer MIGHT get the trainer and power meter to start with less of an offset. This would mean PowerMatch would zero into your target wattage earlier in the workout, but probably not by much.

  2. With a planned PowerMatch update it will be important to do a spin down calibration so that your trainer always measures the same. This update hasn’t started being worked on.

So, if you want to do a spin down calibration, you can. If not, you don’t have to. I personally don’t do it.


4 min of every ride - wasted!

I feel like this needs to be stickied or edited into original post of this thread so its easy to find.
@mcneese.chad or @Nate_Pearson is this possible? Will save a lot of wasted time in responses.

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Can I understand this better please?

So, TR is reading power from your power meter? As also is your Garmin?

But the smart trainer is being controlled by TR right? So, unless your trainer and powermeters are both spot on, the power set by TR might result in a higher or lower power read by the power meter?

Read up on PowerMatch, @deepakvrao

Nate, I fully trust that you guys are all over this (and im not fishing for details as don’t want you to give away any competitive advantage); however, my concern with this would be having to do a spindown prior to a Ramp Test for powermatch to work when the current guidance is to go into the RT cold. Tell me this has been thought about and I’ll go back to my coffee with a smile :laughing:.

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