Stroke Count wrong

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HowardF
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Stroke Count wrong

Post by HowardF » October 24th, 2021, 8:44 am

Did a 3x20:00/1:30r row


Time Meters Pace Watts Cal/Hr S/M
1:00:00.0 13,799m 2:10.4 158 842 19

When I look at the stroke count in the logbook, it is: 778.

My Garmin says 1139 strokes.

19x60 = 1140.
778/60= 13 S/M.

I did the same session October 20 and then it was correct.

What is wrong ?

Other information from Logbook:
Workout
Indoor Rower

Workout Type
Interval:Time

Weight Class
Hwt

Verified
Yes

Entered
ErgData Android
54 years, 183 cm, Norway

strupotter
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Re: Stroke Count wrong

Post by strupotter » October 24th, 2021, 11:04 am

Were you using another bluetooth connection with your phone?
28 / HWT / 185cm
500m: 1:25.0 / 1K: 3:04.5 / 2K: 6:26.9 / 5K: 17:14.8 / 30min: 8191m / 10K: 37:09.2 / 60min: 15836m / HM: 1:22:47.0 / FM: 2:53:29.8

HowardF
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Re: Stroke Count wrong

Post by HowardF » October 24th, 2021, 11:15 am

strupotter wrote:
October 24th, 2021, 11:04 am
Were you using another bluetooth connection with your phone?
Not this time.


( Normaly I do connect to Sonos before I start the ErgData app, but this time i had the TV on)
54 years, 183 cm, Norway

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Citroen
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Re: Stroke Count wrong

Post by Citroen » October 24th, 2021, 2:23 pm

HowardF wrote:
October 24th, 2021, 8:44 am
Did a 3x20:00/1:30r row


Time Meters Pace Watts Cal/Hr S/M
1:00:00.0 13,799m 2:10.4 158 842 19
What are the data for each interval (rather than the whole workout)?

The PM5 uses a very naïve form of maths.
13799/19 is 726 strokes.

How does your Garmin measure a stroke? Is it using an accelerometer? Does it know that a rowing stroke is the full cycle of catch, drive, finish and recover?

HowardF
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Re: Stroke Count wrong

Post by HowardF » October 24th, 2021, 3:09 pm

Citroen wrote:
October 24th, 2021, 2:23 pm
HowardF wrote:
October 24th, 2021, 8:44 am
Did a 3x20:00/1:30r row


Time Meters Pace Watts Cal/Hr S/M
1:00:00.0 13,799m 2:10.4 158 842 19
What are the data for each interval (rather than the whole workout)?

The PM5 uses a very naïve form of maths.
13799/19 is 726 strokes.

How does your Garmin measure a stroke? Is it using an accelerometer? Does it know that a rowing stroke is the full cycle of catch, drive, finish and recover?
Time Meters Pace Watts Cal/Hr S/M
1:00:00.0 13,799m 2:10.4 158 842 19
20:00.0 4,588m 2:10.7 156 838 17
20:00.0 4,569m 2:11.3 155 831 19
20:00.0 4,642m 2:09.2 162 857 20

Yes, i assume Garmin use an accelerometer. Since October 2020 Garmin and loogbook strokes are very similar. Just this session that is crazy.
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Carl Watts
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Re: Stroke Count wrong

Post by Carl Watts » October 24th, 2021, 4:21 pm

ErgData Android works perfectly for me, I mean its pretty easy to check it increment while your rowing if you have the numbers up while your rowing.

Just sit on the rower and row for 1 minute and watch the numbers.

Make sure you have the latest version of ErgData and the latest firmware version on your PM5, that said I have had to stick with V168 because I'm using an older Samsung phone and it had connectivity issues.
Carl Watts.
Age:56 Weight: 108kg Height:183cm
Concept 2 Monitor Service Technician & indoor rower.
http://log.concept2.com/profile/863525/log

HowardF
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Re: Stroke Count wrong

Post by HowardF » October 24th, 2021, 4:55 pm

So the numbers from Ergdata appear to match with your splits. You Garmin app is counting more than a stroke for each rowing stroke - does it think you're running or riding a bike.
When I do indoor rowing, i use the "indor rowing" session for Garmin and nothing else.
Last edited by HowardF on October 24th, 2021, 5:00 pm, edited 1 time in total.
54 years, 183 cm, Norway

HowardF
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Re: Stroke Count wrong

Post by HowardF » October 24th, 2021, 5:00 pm

Carl Watts wrote:
October 24th, 2021, 4:21 pm
ErgData Android works perfectly for me, I mean its pretty easy to check it increment while your rowing if you have the numbers up while your rowing.

Just sit on the rower and row for 1 minute and watch the numbers.

Make sure you have the latest version of ErgData and the latest firmware version on your PM5, that said I have had to stick with V168 because I'm using an older Samsung phone and it had connectivity issues.
Yes, Carl. I see both the spm in the app and PM5 during the training. Nothing strange there.

If you want, You can enter my logbook

Yes, have latest firware version. As said, this is first time, so just maby a one timer bug
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Citroen
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Re: Stroke Count wrong

Post by Citroen » October 24th, 2021, 5:30 pm

HowardF wrote:
October 24th, 2021, 3:09 pm

Time Meters Pace Watts Cal/Hr S/M
1:00:00.0 13,799m 2:10.4 158 842 19
20:00.0 4,588m 2:10.7 156 838 17
20:00.0 4,569m 2:11.3 155 831 19
20:00.0 4,642m 2:09.2 162 857 20

Yes, i assume Garmin use an accelerometer. Since October 2020 Garmin and loogbook strokes are very similar. Just this session that is crazy.
Sorry first go, I had my brain in neutral.

20 mins @ 19spm = 380 strokes
20 mins @ 17spm = 340 strokes
20 mins @ 20spm = 400 strokes

Total 1120 strokes.

Which ain't far short of the Garmin number.

HowardF
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Re: Stroke Count wrong

Post by HowardF » October 24th, 2021, 5:53 pm

Citroen wrote:
October 24th, 2021, 5:30 pm
HowardF wrote:
October 24th, 2021, 3:09 pm

Time Meters Pace Watts Cal/Hr S/M
1:00:00.0 13,799m 2:10.4 158 842 19
20:00.0 4,588m 2:10.7 156 838 17
20:00.0 4,569m 2:11.3 155 831 19
20:00.0 4,642m 2:09.2 162 857 20

Yes, i assume Garmin use an accelerometer. Since October 2020 Garmin and loogbook strokes are very similar. Just this session that is crazy.
Sorry first go, I had my brain in neutral.

20 mins @ 19spm = 380 strokes
20 mins @ 17spm = 340 strokes
20 mins @ 20spm = 400 strokes

Total 1120 strokes.

Which ain't far short of the Garmin number.
Very true. So this is the reason why i do not understand that in my logbook states:
Average Watts 158
Calories Per Hour 842
Stroke Rate 19
Stroke Count 778
Drag Factor 129
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Citroen
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Re: Stroke Count wrong

Post by Citroen » October 25th, 2021, 4:11 am

Now we've collected the evidence send an email to info@concept2.com to ask why it's wrong.

HowardF
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Re: Stroke Count wrong

Post by HowardF » October 25th, 2021, 9:46 am

Citroen wrote:
October 25th, 2021, 4:11 am
Now we've collected the evidence send an email to info@concept2.com to ask why it's wrong.
yes, I have sent them the mail.
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nick rockliff
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Re: Stroke Count wrong

Post by nick rockliff » October 25th, 2021, 10:51 am

Looks like only the strokes from two of the reps have been recorded for some reason.
67 6' 4" 108kg
PBs 2k 6:16.4 5k 16:37.5 10k 34:35.5 30m 8727 60m 17059 HM 74:25.9 FM 2:43:48.8
50s PBs 2k 6.24.3 5k 16.55.4 6k 20.34.2 10k 35.19.0 30m 8633 60m 16685 HM 76.48.7
60s PBs 5k 17.51.2 10k 36.42.6 30m 8263 60m 16089 HM 79.16.6

Tsnor
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Re: Stroke Count wrong

Post by Tsnor » October 26th, 2021, 4:23 pm

FWIW. I used to see a similar problem. Maybe you have the same problem, maybe different. There was a fix in the March 2021 firmware level with a companion Ergdata change. If you are not current grab those. I haven't seen any problems since loading that firmware, but I also stopped using bluetooth and started using a cable. Support was very helpful.

Check the PM5 display. Compare the last interval as reported in the PM5 with the interval reported in either ergdata or the log. If its the same problem the PM5 will report different data then ergdata or the C2 log. The last interval(s) in the logbook are fantasy. If you download the per-stroke data as CSV its even more obvious.

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Re: Stroke Count wrong

Post by chrisl » October 31st, 2021, 10:10 am

This looks like the same underlying bug I reported to C2 in March 2020. I would get a disconnect part way through (beta testing a development version of ErgData) and I noticed that this would result in the logbook showing Stroke Rate and Stroke Count ONLY for the part of the session before the disconnect.

In your case you appear to have had a blip in your connection to the PM5 after 778 strokes and that's caused the halting of stroke collection, and a later sync has allowed ErgData to pull in the main piece but retain the incorrect stroke data. Here's part of the email I sent to C2 along with an example from the logbook - see the image attached. The case was passed on to someone I was already in touch with but there was no followup.

Edit - Unable to attach image to post, so it's here - https://drive.google.com/file/d/1ipO1dy ... a_24G/view

--------------------------------
I'm reporting a bug with ErgData and/or the online logbook.

ErgData sometimes loses the connection with the PM5 part way through a session and acts as if bluetooth has been turned off. It displays either the usual white pop-up info box which says "PM5 ... Connect ... PM3/4 ... OK" or else it simply shows the main ErgData display with the "Please Enable Wireless on PM" message at the bottom.

Meanwhile the PM5 continues to run and record the session as if nothing has happened. Once the session has come to an end, the PM5 correctly shows the data it has recorded for the session and splits as normal.

ErgData does not have the session listed. However if they are once again connected via bluetooth and a new session is completed (eg a 70 second Just Row to get it to register), when that new session is saved, the previous disconnected session is also pulled into ErgData. Both sessions are now ready to sync.

So far everything looks good. However when these are synced to the online logbook and the disconnected session is examined online, the total distance, time and pace are correct as per the entire session from the PM5, but the stroke data, stroke count and perhaps some other numbers are incorrect and relate to just the data which ErgData saw before it disconnected.

Attached is an example from my logbook - ErgData lost the connected to the PM5 after around 50 minutes. The total time rowed was 1 hr 15 mins. You can see the correct time at the top, but the log entry shows that I did it in 1177 strokes at a rate of 24 strokes per minutes. That comes to a total of 49 minutes, NOT 1 hr 15 mins. And as you can see this is a Verified piece.
--------------------------------
Last edited by chrisl on October 31st, 2021, 10:16 am, edited 1 time in total.

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