# frequency of smart-trainer calibration



## DaveG (Feb 4, 2004)

I have a wheel-on style smart trainer (CycleOps Magnus). I do a spin-down calibration every couple of weeks or so. My trainers requires about a 10 minute warm-up before you can calibrate so its a pain to do one. I have read some folks do it every ride. My thinking was that if I maintain constant tire-pressure and don't remove the bike from the trainer, I should not be deviating much from the last calibration. How often do I need to do this?


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## DonBjr (Oct 4, 2014)

DaveG said:


> I have a wheel-on style smart trainer (CycleOps Magnus). I do a spin-down calibration every couple of weeks or so. My trainers requires about a 10 minute warm-up before you can calibrate so its a pain to do one. I have read some folks do it every ride. My thinking was that if I maintain constant tire-pressure and don't remove the bike from the trainer, I should not be deviating much from the last calibration. How often do I need to do this?


Room temperature would also need to stay constant. -possibly humidity also I suppose.

My unfinished basement's temperature swings quite a bit between seasons, and it seemed to throw the calibration off in that a re-calibration in the summer after months of not doing one, totally changed my threshold watts.


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## Srode (Aug 19, 2012)

Depends on the trainer - With the Elite Drivo you really never need to calibrate it.


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## DaveG (Feb 4, 2004)

Srode said:


> Depends on the trainer - With the Elite Drivo you really never need to calibrate it.


That is one of the benefits of a direct drive trainer. My cheapness prevented me from going that route


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## Chader09 (Jun 10, 2014)

CycleOps:
"we recommend performing a calibration as frequently as you wish to keep your power numbers as accurate as possible."
Per: https://www.cycleops.com/post/blog-smart-trainer-calibration-hot-and-cold

Wahoo says to do a calibration for every ride.
Edit: This is for the KICKR SNAP. The wheel-off KICKR is only every 2 weeks.

Ultimately, there are too many variables with wheel-on trainers to expect consistent, accurate results without a 10 minute warmup and a calibration.


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## RL7836 (Jun 17, 2014)

Chader09 said:


> Wahoo says to do a calibration for every ride.


I recently asked a buddy how he likes his Wahoo Kickr. He said that the 'required' calibration is a pain. This was something I hadn't noticed in reviews. I currently use an older Kurt Kinetic wheel-on trainer (with my own Powertap wheel) but I've been considering an 'upgrade' to one of the newer high-end units. When he first told me, I thought 'what a whiner - such a small issue'. However, thinking more about it & how time-crunched I am typically, I can see that adding a 10-15 min warm up followed by a calibration before I even start TrainerRoad may indeed be a pain ... hmmm ...


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## Chader09 (Jun 10, 2014)

RL7836 said:


> I recently asked a buddy how he likes his Wahoo Kickr. He said that the 'required' calibration is a pain. This was something I hadn't noticed in reviews. I currently use an older Kurt Kinetic wheel-on trainer (with my own Powertap wheel) but I've been considering an 'upgrade' to one of the newer high-end units. When he first told me, I thought 'what a whiner - such a small issue'. However, thinking more about it & how time-crunched I am typically, I can see that adding a 10-15 min warm up followed by a calibration before I even start TrainerRoad may indeed be a pain ... hmmm ...


For clarity, wheel-off vs wheel-on have two different calibration frequency requirents:

*KICKR *(Wheel-Off):
"We recommend performing a spindown approximately once every two weeks or after transporting your KICKR."

https://support.wahoofitness.com/hc...I-perform-a-spindown-calibration-on-my-KICKR-

*KICKR SNAP *(Wheel-On):
"For the Snap, we recommend performing a spindown at *the start of every workout*."

https://support.wahoofitness.com/hc...orm-a-spindown-calibration-on-the-KICKR-Snap-

So, they are VERY different. If you have a regular KICKR, you don't need to calibrate every time, but you do for a SNAP.


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## hrumpole (Jun 17, 2008)

Chader09 said:


> For clarity, wheel-off vs wheel-on have two different calibration frequency requirents:
> 
> *KICKR *(Wheel-Off):
> "We recommend performing a spindown approximately once every two weeks or after transporting your KICKR."
> ...


I have a snap. Most of the time I run the power through power match or similar, so calibration doesn't matter. But before I did that what I used to do was simply start a workout and do the warmup, and then 10 minutes in pause and do a spin down. It takes about a minute, and s--t tends not to get real in trainer road or the sufferfest 'till about 10 minutes in anyway. The only time I might consider NOT doing that is during a fitness test, when the rest periods and everything else are supposed to be relatively constant and repeatable, and an extra 10 min would be helpful. YMMV.


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## DaveG (Feb 4, 2004)

hrumpole said:


> I have a snap. Most of the time I run the power through power match or similar, so calibration doesn't matter. But before I did that what I used to do was simply start a workout and do the warmup, and then 10 minutes in pause and do a spin down. It takes about a minute, and s--t tends not to get real in trainer road or the sufferfest 'till about 10 minutes in anyway. The only time I might consider NOT doing that is during a fitness test, when the rest periods and everything else are supposed to be relatively constant and repeatable, and an extra 10 min would be helpful. YMMV.


hrumpole, what do you mean by "power match"? A separate power meter?


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## Chader09 (Jun 10, 2014)

DaveG said:


> hrumpole, what do you mean by "power match"? A separate power meter?


Yup, he is using a power meter to report actual power. Apps like TrainerRoad read that power meter, then adjust the trainer resistance level to hit the ERG power target.

Two advantages:

1) It is commonly more accurate to use the power meter rather than the trainer power.

2) You are using the same power meter that you use outside, so comparing efforts is closer (with the inside vs outside effort capabilities being the big remaining variable).


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## Chader09 (Jun 10, 2014)

hrumpole said:


> I have a snap. Most of the time I run the power through power match or similar, so calibration doesn't matter. But before I did that what I used to do was *simply start a workout and do the warmup, and then 10 minutes in pause and do a spin down.* It takes about a minute, and s--t tends not to get real in trainer road or the sufferfest 'till about 10 minutes in anyway. The only time I might consider NOT doing that is during a fitness test, when the rest periods and everything else are supposed to be relatively constant and repeatable, and an extra 10 min would be helpful. YMMV.


That is the best approach. I do the full warmup and do the Zero Offset right after hitting the peak of the warmup, when you get a few minutes before the first real interval.

It's an easy habit to form and barely affects the workout effort. Then you know you are getting the best possible results and accuracy from the trainer.


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## Jwiffle (Mar 18, 2005)

DaveG said:


> That is one of the benefits of a direct drive trainer. My cheapness prevented me from going that route


Some direct drive trainers doe not require calibration, like the Neo. Others, like the kickr already mentioned, do. My Hammer also required calibration anytime you installed a bike (if you left it on between rides, a calibration was not required).


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## OldZaskar (Jul 1, 2009)

I have a Kickr (2017 Edition) and an SRM power meter. Out of the box the power matched the SRM and after a couple weeks and four rides (weather's been great in Atlanta), the power numbers are still matched. I'm thinking I'll not do a spin down until (if?) the power data no longer lines up.


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## HEWSINATOR (Sep 18, 2005)

RL7836 said:


> ... I currently use an older Kurt Kinetic wheel-on trainer (with my own Powertap wheel) but I've been considering an 'upgrade' to one of the newer high-end units.


What do you use for power outside? If the PowerTap wheel you may want “wheel on” to maintain power consistently in and outdoors. 

And, for what it is worth, I have yet to find better “feel”than. Kurt Kinetic Road Machine II; thought I wanted an Erg but tried a cyclops and didn’t love.


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## Chader09 (Jun 10, 2014)

HEWSINATOR said:


> What do you use for power outside? If the PowerTap wheel you may want “wheel on” to maintain power consistently in and outdoors.
> 
> And, for what it is worth, I have yet to find better “feel”than. Kurt Kinetic Road Machine II; thought I wanted an Erg but tried a cyclops and didn’t love.


I love my old Road Machine but the Wahoo KICKR and CycleOps Hammer have amazing road feel. On ERG, I didn't love it on my old CycleOps PowerBeam Pro, but ERG works really well on the KICKR and Hammer.

The issue of potential differences between the trainer an PT Hub is real, but usually low enough to be a minor one.


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