Drag Factor changed between warmup/workout

[allimprov]

Hi,

Today I did a 16 minutes warmup followed by a 30 minutes workout. I haven't changed the drag factor for several days (I kept it at 118), and neither did I change any settings between the warmup and the workout.

However, for some reason, the drag factor was recorded as 118 during the warmup but 146 during the workout, and I have no idea why?

The warmup was quite slow and steady, while the workout was a 1' max effort followed by 2' slow and steady rest, 10 times.

How could this happen and can I trust the drag factor recorded in the workout? Could it be because I started the workout right in the max effort zone and push/pulled as hard as I could? (hence, it could have recorded the very first stroke's high drag factor because the flywheel was still, and kept it in memory for the rest of the workout?)

Thanks

[Elizabeth]

Assuming you are talking about the RowErg, the PM5 recalculates the drag factor on every stroke. I'm pretty sure that the displayed drag factor in the logbook shows the average drag factor for the row. I found a session where I started at DF 110 and then increased it to DF 135 for the end (I was warming up for a sprint), and my logbook shows DF 125.

It shouldn't change based on how hard or easy you are pulling.

Variations of 1-2 are super common, I will frequently see 111-110-112 as I row. If you are outside, a big gust of wind can change it even more. Moving the erg so that there's more or less air movement also seems to make a difference - especially if the fan cage is moved really close to a wall or something. But the kind of jump that you're talking about is so much that I wonder if there was some sort of bug in the calculation.

Sorry I'm not of more help.

[Joebasscat]

See my post from 10/22 “ErgData and Drag Factor.”

C2’s response was they could not identify at this time why that was happening. Your issue seems similar to my experience.

[Dangerscouse]

That does seem very strange. Did it feel different?

[Sakly]

What device do you use? IOS or Android?

[allimprov]

Thank you everyone for your replies.

@dangerscouse: it didn't feel different at all, which is the interesting part.

@sakly I use ErgData on Android and always used the same phone/C2.

@joebasscat Checked your post and indeed, it looks quite similar.

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Yesterday I tried to replicate that in 2 steps (1: row lightly to measure the DF, stop, and then row as hard as I can for a few strokes and measure the DF again) but the DF stayed the same.

Maybe is it some kind of bug. It would be nice if we could manually edit the DF in the Logbook to correct, although it would not fix the root issue.

[Joebasscat]

My first occurrence was on 9/28 and has done so on SS rows since. Prior to that, all good. All over 60”. I did a 30r20 on Saturday and all reported correctly. I increased my power on my SS on Tuesday and the error was present. I remain stumped.