Incorrect Strokes per minute

[TheJackal]

Hi,

I've used my new RowERG approximately 10 times since I bought it a couple of weeks ago.

All good until today...

I do a 40 minute row with 2 minute splits of 18, 21, 24 and 27 strokes per minute.

So far I've been improving the accuracy of my stroke rate until today when according to my PM5, I was completely all of the place. Nothing random but definitely completely different stroke rates than I was seeing on the PM5 as I rowed.

Any ideas?

[MPx]

Its probably a combination of the reading for the last stroke and a rounding issue. Some of the split data is recorded from the last stroke of the split instead of an average for the split which would seem more intuitive. I know for a fact the HR number is from the last stroke - but I dont know if its the same for stroke rate. The other oddity is rounding where, C2 decided in their first iteration of soft/firmware to adopt a rounding down policy (no matter the size of the fraction over), and that too can also have surprising effects. C2 have prioritised consistency across generations of equipment rather than fixing things to be "better" but different. So we've all come to just live with these anomolies when we see them. Of course these numbers have zero effect on training or competitions where everything is the same for everyone - so there is some logic there at least!

[jamesg]

If you use a C2 logbook, you can see ratings for each single stroke in the graphs. All displays of rating show as a 2-figure number, ignoring decimals.

The numerical data is also listed, with lines for the total and for single splits or intervals.

Logbook shows the total number of strokes, so we can calculate averages for Work per stroke, rating and meters per stroke, if interested.

[iain]

I do a 40 minute row with 2 minute splits of 18, 21, 24 and 27 strokes per minute.

So far I've been improving the accuracy of my stroke rate until today when according to my PM5, I was completely all of the place. Nothing random but definitely completely different stroke rates than I was seeing on the PM5 as I rowed.

Any ideas?

One possibility is that it is possible for a stroke to count twice if there is a part of the power stroke when you weren't accelerating the flywheel. If you put on the force curve you will see this as the curve dropping to zero in the middle of the stroke. Unlikely if you are an experienced rower, but worth eliminating.

[dabatey]

I do a 40 minute row with 2 minute splits of 18, 21, 24 and 27 strokes per minute.

So far I've been improving the accuracy of my stroke rate until today when according to my PM5, I was completely all of the place. Nothing random but definitely completely different stroke rates than I was seeing on the PM5 as I rowed.

Any ideas?

One possibility is that it is possible for a stroke to count twice if there is a part of the power stroke when you weren't accelerating the flywheel. If you put on the force curve you will see this as the curve dropping to zero in the middle of the stroke. Unlikely if you are an experienced rower, but worth eliminating.

Were you practicing sequencing your stroke legs/hips/arms type thing. I wonder if you could break pulling between 'sections' enough to cause what Iain has said if that were the case.