Two power sources, how to deal with discrepancy

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1

I have a new 4iiii crank PM and a Saris H3 trainer, all calibrated and consistent with themselves but the H3 reports power ~3-5% lower pretty consistently on dual-recording zwift and workout efforts. Most of my profile data is from the latter (lower) H3 source. Using the crank PM for Xert workouts is a bit trickier; it’s generally more finicky to connect with my Android device and it also has noticeably more “lag” time for power readings so spinning up for short intervals are a bit wonky.

So, I would prefer to use the H3 for indoor workouts and of course the crank PM for outdoor rides. Will this level of difference be noticeable in how workouts and progression are generated? Or is that level of discrepancy just in the noise anyways (particularly when comparing indoor/outdoor efforts)?

Would it be worth using the 4iiii configuration to reduce the power to match the H3? I hate to leave watts on the table, particularly when Zwift racing starts up for me in the fall/winter again. :slight_smile:

Thanks for the advice.

2

Hi Ben,

I’m pretty sure the 4iiii’s app allows you to bias power up or down as a percentage. Go into their app and connect to your power meter, then adjust the setting there so that you get more consistent results.

Let us know how you make out.

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