Power differences between Strava, Garmin & Quarq

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Tonytony
Posts: 58
Joined: Wed Jun 24, 2020 1:04 pm

by Tonytony

Last ride my (avg/NP) power was:
Garmin: 213W/231W
Strava: 185W/219W
Quarq: 178W/228W

The difference in avg power between Strava and Quarq comes from moving time vs elapsed time. But how is the difference so big between my head unit and Strava? Is it because my head unit records without zeros? When I compare to other riders who are riding with me (almost the same weight and effort), they have higher numbers on strava but almost equal on their head unit.

I have a garmin edge 530 and quarq sram axs D1 powermeter.
I've read that more users of the edge 530 are have this issue.

TobinHatesYou
Posts: 12456
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

Probably yes, recording zero cadence or zero power vs omitting that data entirely while still moving.

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Tonytony
Posts: 58
Joined: Wed Jun 24, 2020 1:04 pm

by Tonytony

The avg of the power and cadence is higher if you record without zeros, am I right? But strava is taking the data with zeros

TobinHatesYou
Posts: 12456
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

Strava does use it own map data to calculate speed, distance, elevation correction, etc. That's why you'll see crazy speeds or elevation if your GPS erroneously has you riding off the edge of a mountain road. I could see how that would would result in a different "moving time."
Last edited by TobinHatesYou on Fri Apr 16, 2021 10:10 am, edited 1 time in total.

petromyzon
Posts: 781
Joined: Mon Apr 05, 2010 4:14 pm

by petromyzon

Tonytony wrote:
Fri Apr 16, 2021 9:07 am
The avg of the power and cadence is higher if you record without zeros, am I right? But strava is taking the data with zeros
It is convention to include zeros when averaging power but remove them when averaging cadence.

Tonytony
Posts: 58
Joined: Wed Jun 24, 2020 1:04 pm

by Tonytony

Thnx!!

reedplayer
Posts: 816
Joined: Sat Nov 14, 2015 10:10 am

by reedplayer

...and: dont be surprised about diferences in "NP" ("XP" at strava) between "garmin" and "strava", even, if "AP" is identical. they are using slightly different algorithms ("garmin" is always calculating higher numbers).

strava (using the same algorithm like golden cheetah) is closer to reality.

regards

by Weenie


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