TANC

After my ride today, I see significant differences in NP, IF, and TSS on the Edge 500 and in Golden Cheetah after the upload. Using a new Powertap G3. And, yes, I have pause turned off and zero averaging on. And also have 1 second recording on vs smart recording. Numbers are higher on the Garmin. Quite a bit higher. NP on Garmin is 250. GC says 220....as an example.

Anyone know why.

My first Powertap ride.

gregf83 

Post a link to your file on Garmin connect.

TANC

What will that tell you?

ancker

One reason might be Golden Cheetah or Garmin using different times for displaying averages.

On Garmin Connect it gives you Time, Moving Time, and Elapsed Time. All with different times. Perhaps GC uses a different (longer) number than Garmin.

(Also, GC is a bit ambiguous as it could refer to Garmin Connect or Golden Cheetah.)

TANC

Edge and Garmin Connect show the same numbers, but they are 10-15% higher than what Golden Cheetah shows.

gregf83 

I don't know until I see the file. Golden Cheetah works well and I trust it. If I look at your file I could probably tell you why Garmin was giving you different readings.

TANC

It appears Garmin gives me a good IF and TSS based on the NP it calculated, which makes it obvious to me that Garmin and analysis software like Golden Cheetah don't calculate NP the same way. I have an email to Garmin asking why, but I expect them to dance around the question. But we will see.

Gluteus

Garmin gives you an "elapsed time" and a "moving time"
I believe the power numbers in Garmin connect are based on the "moving time", so if you stop several times during the ride and Golden Cheetah is not correcting for this that might be an issue.
Where in Garmin connect are you seeing NP?
I only see average power (which as you know is not the same).

TANC

Gluteus,


Thanks for your response.


Garmin Connect displays 7 categories of power metrics for me. NP is one of them. Are you using a Powertap and the Edge 500 ?


Otherwise, you may be onto something. I did stop yesterday three times for a total of about 7 minutes. Stopped first to wipe water out of my eyes that was blinding me. From pollen I guess. Happens to me a lot this time of year. Stopped a second time to change a couple of my display settings on my Cerevellum. Still getting used to it. Stopped a third time to eat a cookie and gulp some liquid. Again, a total of about 7 minutes according to Garmin.


But this would make sense to me. If the Garmin only calculates NP using "moving" speed, it would have not accounted for those 7 minutes where Golden Cheetah, I think, accounts for every second, riding or not, until the data collection is stopped. And I had auto pause turned off.


On the Garmin and in Golden Cheetah, zero averaging for power would account for no power when coasting downhill, and would not see that as stopped in either case since there's still speed, so they both should be the same there.


So I guess if I want data recording to stop when I stop, for the sake of both looking identical, I need to turn auto pause back ON even though everything I read says turn it off. The real question, I guess, is if it's more important to me that they match, or is it more important to me that Golden Cheetah shows the data INCLUDING my stops, which is more real, theoretically, even though the Garmin apparently will not account for stops no matter the setting if it uses only moving speed. I'm leaning toward turning auto pause back on since I'm used to trainer road and virtual power, and it uses only the moving data as best I can tell. I'm pretty sure data recording stops when you stop in trainer road. And Golden Cheetah only sees the uploaded recorded data. So if I want to see indoor to outdoor equal comparisons, that's the best way to do it.


Now if Garmin doesn't use only moving speed, then all these theories are out the window.


I guess another way to be sure they are equal is not to stop. Also a good way to verify your theory.

TANC

Read last night that power readings/data are unaffected by the pause function on the Edge, so now I'm confused again. Says it records the data non-stop even if pause is turned on.