500m World Best Score?

[johnlvs2run]

Regarding the pm1 and max split:

The instantaneous display on the pm1 was different than the resulting pace that came out on the average. The instantaneous display might show 1:58 consistently, then the average pace would come out 2 to 3 seconds slower.

Thus the instantaneous display was accurate and consistent, while the conversion issue was with the average pace.

The instantaneous display was consistent in line with the reading of watts, the average pace was inconsistent and variable. For these reasons, I feel the instantaneous display on the pm1 was accurate. It was the average pace that was not accurate, because the conversion of watts to the average pace was not accurate.

The instantaneous display reading on the pm1 was either the same as on the pm2/4, or else at the least was very close, and was much closer to being the same than was the average pace reading.

I saw many issues of the average pace reading not being accurate or consistent on the pm1, but never saw any issue as with the instantaneous display on the monitor. As far as I am concerned, the instantaneous display on the pm1 monitor is the same as on the pm2/4 monitors.

[rlholtz]

If the PM1 (which is the only monitor I have experience with) is that advantageous to faster pieces, why aren't people clamoring for them and using them in the rankings where it appears they're acceptable?

[Sir P]

Very interesting thread this one

I would just like to add-
Chad, that is some amazing power you have. That 500m works out at 19.3 SPI

When you put this into perspective with Graham Benton’s 2000m time of 5:43.7 rowed at 30spm it equates to 18.4 SPI.
Does this point that Graham may be able to pull the sort of 500m time Chad is, I think Grahams 500m time is 1:14.8 but done many years ago.

Chad is averaging 19.3 SPI for 72 seconds and Graham is averaging 18.4 SPI for 343.7 seconds. This shows the amazing power some of these big guys have.

[PaulS]

If the PM1 (which is the only monitor I have experience with) is that advantageous to faster pieces, why aren't people clamoring for them and using them in the rankings where it appears they're acceptable?

I don't think that there are very many that would care about having an artificially aided ranked piece. Plus there would be no chance of a verification code, as is in use today. Finally, eventually electronics die, there hasn't been a PM1 produced in more than 10 years, if production stopped when the PM2 was introduced. You'd be hard pressed to get a PM2 these days, and the PM3-4 can be retrofitted to all previous models of the Erg.



John,

Chart of PM1 Vs PM2 and later. Gathered and extrapolated data.

I simply did test 500m Pieces and used the elapsed times from both PMs as the avg pace for the piece. The instantaneous displayed paces would not have been consistent enough to use. That you think it would have been, is indicative that you have not actually run them simultaneously; And no, "feel" is not good enough. Unless you run the PMs at the same time, off the same flywheel, you would be making no valid observations as far as you are concerned. Your torturous justifications are becoming quite entertaining. It reminds me of your antics of old; Is your resolution wearing off?

[rlholtz]

Okay. So if I do a 7:02 2K and 15200 60 min row on a B with a PM1, what does that translate to on a C or D with a PM 2, 3 or 4 - or a B with a PM 2, 3 or 4 for that matter?

Thanks in advance for any input.

[johnlvs2run]

To be more clear with my previous messages, there is a difference between the instantaneous display on the pm1, and the average pace on the pm1.

AVERAGE PACE
The average pace on the pm1 is not consistent or accurate. Based on the internal conversion of pace from the watts, the average pace might come out 2 to 3 seconds slower, or 2 to 3 seconds faster than a direct mathematical calculation from the watts. This is regardless of the pace. The pm1 average pace was not suddenly accurate at one pace and not at another. The average pace was not consistent and not accurate at any pace. It doesn't matter if the pace was 1:58 or 1:49 or 1:22, the average pace on the pm1 is not consistent and not accurate.

INSTANTANEOUS DISPLAY
The instantaneous display on my pm1 have given exact consistent results with my rowing. Given the same even effort, every stroke on the instantaneous display is the same. Additionally, the overall results from the instantaneous display are consistent with the watts.

VALIDITY OF TESTS
Doing 500m test pieces would result from the average pace of the distance, not the instantaneous pace. Were such times taken from the average pace of the monitor, and not calculated mathematically from the watts, they would not be consistent nor accurate, and the results would be variable from one test to another. For a test to be statistically valid, it needs to be reliable from one test to another.

MATHEMATICAL VS INTERNAL CONVERSION
I think we can agree that the average pace on the pm1 was not calculated internally accurately from the watts. It was not only not accurate but the results would change from one piece to another. One time the internal conversion might be 2 to 3 seconds slower than a direct conversation from the watts. Another time it might be a second or so faster. However, a direct mathematical conversion from watts to pace is (has to be) exactly accurate every time and from one time to the next.

CONCLUSIONS
In my experience with these various conversions and the different times and paces, which is considerable as I have rowed more than 35 million meters on the concept2 ergs, I can say with relatively precise certainty that (1) the average pace on the pm1 is not accurate nor consistent, and (2) the instantaneous display is quite precisely consistent and accurate as compared to the watts.

I am not trying to put anyone in a corner here, and I welcome any different ideas. If anyone has any experiments that show otherwise then I will be glad to look at them but as always will make up my own mind about their veracity.

[johnlvs2run]

Okay. So if I do a 7:02 2K and 15200 60 min row on a B with a PM1, what does that translate to on a C or D with a PM 2, 3 or 4 - or a B with a PM 2, 3 or 4 for that matter?

Thanks in advance for any input.

You would count the time as the same.

Prior to getting the pm2+, I had started calculatiing my times mathematically from the watts, as that was more precise, though I still used the displayed and slower times for the rankings. However, doing this was quite educational as to the functioning of the p1 monitor. After obtaining the pm2+ I could see that the watts readings on both were the same, the difference being the pm1 conversion of average pace from the watts.

If you want to get the accurate conversion, then you'll need to convert the watts to pace mathematically.

[rlholtz]

May I have the formula?

[PaulS]

Okay. So if I do a 7:02 2K and 15200 60 min row on a B with a PM1, what does that translate to on a C or D with a PM 2, 3 or 4 - or a B with a PM 2, 3 or 4 for that matter?

Thanks in advance for any input.

If you retrofit your Mod B with a Newer PM the times simply become directly comparable to the Newer models. The Moment of inertia of the flywheel's from the B onward are the same, which is why the power input requirements will be the same.

Your 7:02 2k on the PM1 would be about a 7:06 on the PM2.

The 1:58.4 avg pace for 60 minutes on the PM1 would be about a 1:58.1 on the PM2, so about 15,240m.

Note: Sorry, had to work out the numbers a bit more closely for the 1:58.4, as it's so close to the 1:55 equivalence point that the difference is quite minor, about 2 watts.

[johnlvs2run]

watts = 2.8 / pace^3

watts / 2.8 ... 1/3 root ... divided by 500 ... inverse ... = pace

Or just use the watts/pace calculator on this page.
http://www.machars.net/spi.php

[johnlvs2run]

More precisely, a 7:02 on the pm1 would be in the range of a 6:50 to 7:06 on the pm2/4.

A 1:58.4 average for an hour on the pm1, would be an average pace of 1:55 to 1:59 on the pm2/4.

Or just use the formula and convert your pace from the watts.
http://www.machars.net/spi.php

[PaulS]

More precisely, a 7:02 on the pm1 would be in the range of a 6:50 to 7:06 on the pm2/4.

A 1:58.4 average for an hour on the pm1, would be an average pace of 1:55 to 1:59 on the pm2/4.

Or just use the formula and convert your pace from the watts.
http://www.machars.net/spi.php

John, that's just wrong. The PM1 did fine on calcualting watts. You demonstrate this by using the conversion formula on watts to get a similar paces to what the PM2 would calculate. There is no 16 second range in the possible outcome in the range of a 1:45 pace, the PM1 has a 1 second Pace advantage at that point. That is to say that if both PM's were running off the same flywheel and the PM1 gave an elapsed time of 7:02 for a 2k, the PM2 would give an elapsed time of 7:06, both will have had an average watts of 289, but the PM1 gave more boat speed for that power input.

If you want to be incorrect and accept that as your own conclusion, that is fine, but is a choice you are making, to ignore the facts. That makes no sense, but go right ahead if it makes you happy.

[johnlvs2run]

I have tested the pm1 on a large number of occasions, and consistently found (1) the internal conversion of watts to pace to be variable (and thus inaccurate and unreliable), and to be different from the (2) mathematical calculation of pace from the watts. Of course the mathematical calculation of pace from the watts is correct.

That the internal conversion of watts is consistently different from the mathematical calculation of watts is conclusive that the internal conversion of watts on the pm1 is not reliable and not accurate. I have found the range of internal conversion of watts to pace on the pm1 monitor to vary by +/ 3 seconds per 500 meters as compared to the mathematical calculation of watts to pace on the pm1 monitor.

As the watts are the beginning point of all these calculations, and the mathematical calculation of the pace is correct, that the internal calculation is different and variable means that it is not correct and not accurate.

This was very easy to test and I did it many times. When you row a piece with the pm1 monitor and get the time/pace for a distance, then compare this with the mathematical calculation of time/pace and these turn out to be different; this means that the mathematical calculation of pace is correct and the internal conversion to pace is not right.

[Nosmo]

John & Paul,


John, are your measurements done with average watts? IF the pace on multiple pieces is variable you will end up with different average speeds for the same average power.

You both seem to agree that the watts were correct.

Another possibility is that you had different firmware versions on your PM1's, resulting in different experience or times.

My experience was my PM1 monitor always had an instantaneous speed lower then the average. To row a steady 20 min 5K I had to keep the pace below 2:00.

[johnlvs2run]

John, are your measurements done with average watts?

Yes, for individual pieces. I didn't bother to do this for reps.

You both seem to agree that the watts were correct.

Yes we appear to agree on this.

The pm1 didn't have any firmware. Probably the only way the difference can be found is to calculate the watts mathematically, to compare each individual result with the internal conversion of each individual piece, and then to keep doing this a significant number of times. For there to be no difference, then the two results must be identical indefinitely. However I found them to not be the same even once.