Power meters vs kickr

Equipment
1

I have a kickr c. 2016 and for a long time I used to use a single sided power meter (Garmin) for consistency. I was super happy with this and absolutely loved doing my tr sessions indoors

Earlier this year I got a new bike and along with that I got dual sided Garmin pedals. My old bike and single sided power meter were to remain as a turbo bike (also my new bike need the kit to be able to use it) Admittedly this year I have done the least amount of turbo work and done most of my tr sessions outside. My power has been great outside and has increased a bit through the year.

The handful of sessions I have done indoors have been awful. Sessions I would have easily done out side were so hard to the point I could not complete them indoors. I have tried putting the pedals on my old bike but still have the same issue.

I’m really hating training indoors atm the moment and not looking forward to the winter! :weary: interestingly, when I’ve used the kickr power and hooked up my power meter to my head unit for comparison the effort feels more like it does outside but of course the power reading from the Garmin power meters is lower… don’t know what to do for the best! Any suggestions or has anyone else experienced this?

Thanks In advance

2

Just a thought
When you went from inside to outside was the power meter reading with new pedals the same as it was inside with the single sided power meter?

3

Not 100% sure but it felt easier on the new bike for sure. But put that down to the massive difference in the bikes, ages, position, tech.

4

Also, put new pedals on the turbo bike and cannot replicate outdoor power

5

Some basic questions / double-checks:

  • You have the correct crank length set for each set of power meter pedals?

    • This is essential, but extra important if you happen to have different length cranks between bikes.

  • Did you properly torque the pedals for each use case?

    • The latest Garmin’s seem to be at least a bit susceptible to given flawed data if not torqued to spec.

  • Do you regularly calibrate each pedal set before use?

As mentioned above, even if everything is perfect above, there can be enough leg imbalance for some riders to result in notable differences in reported power when comparing single-sided to double-sided power meters.

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6

Thanks chad.
Yes is the answer to all questions. :man_shrugging:

7

If you really want to dive into this, you need to do a structured comparison with your trainer as the constant while testing each pedal set against it. Use comparison tools to see how each PM stacks up to the trainer, and you may have an understanding of what’s happening.

Short of that, some hack testing with one device connected to the trainer, other to each PM during the test may shed some quick light on the situation.

8

What did you use to set your FTP? In theory I think you just have one FTP (you are one person regardless) but in practice with more natural air cooling, momentum etc power for most is easier achieved outside. If your FTP was set outdoors it could be a little too high indoors and pushing you over the edge.

9

FWIW, I was searching around the other day and found this site that will compare .fit files for free:

Last time i did it, I did this complicated dance with Golden Cheetah and Excel.

2 Likes
10

Sweet, I will add that to my FAQ :smiley:

11

Thanks all. Going to to do a bit more of a detailed comparison on the PM’s will feed back if it sheds some light on the situation. :pray:

1 Like