Watt readings on two ERGs

[joelsmartin]

I searched but didn't see anything on this. I have a Model D/PM5 at home and my gym has a Model D/PM5 also. When I'm home and rowing hard I get the watts reading up to the low 200's and don't think I ever get over 230 watts. Talking to my trainer at the gym and she mentioned seeing other rowers watts outputs in the 300-400 range. I got on the rower at the gym and also showed watts in the high 300's. I know my DF at home is set to about 122 but didn't check the DF on the gym rower.

Is it unusual for different rowers to show that big a difference in watts? Would the DF effect it to that large an extent? I'm going to row at home later and will play with various DFs to see what it does but thought someone might know if this is normal, or indicates a defective ER (mine or the gyms), or maybe n ERG that needs some maintenance?

[Citroen]

1. Are they at roughly the same elevation?
2. Are the fan cages clean?
3. Have you set the drag factor to the same number on each ergo?

https://www.concept2.com/indoor-rowers/ ... etting-101

The first move will be to open the fan cage at the gym and remove all of the dust and cruft that's collected in that machine since it was first delivered,

[joelsmartin]

Thanks for the reply.

1 - Yes, same elevation
2 - Both cages look clean but I have not opened them up.
3 - I didn't check the DF on the gym erg. But that is part of what I am trying to understand. Will a low DF equate to a higher watt reading (or the other way around)? Based on the "feel" of rowing on both I would guess the gym has a lower DF than my home. Damper setting was the same on both, which I realize is not equal to DF, but I would assume them to be close.

[Carl Watts]

Just make sure that they are set to the right model of rower in the product ID screen.

Small mechanical difference can lead to some psychological stuff, I mean the gym machines can be horrible with stuffed chains, shock cords and stuff on monorail. You wouldn't want to train on some of these machines, let alone try and race on one.

Typically the gym machines are very dirty and the drag factor is crazy low, you simply cannot get the power into one of these where the resistance is to low.

[MPx]

But the OP is reporting differences the other way around suggesting his machine is the dusty one and the Gym m/c in better nick.

For Joels ref: You are more likely to be able to generate a higher wattage stroke with a higher DF, but you wont be able to do it for long. The effect of dust in the cage is to lower the available DF. Small changes in DF are not particularly detectable or relevant for perceived effort. Its very obvious if one machine has a DF of 200 (each stroke very heavy and probably slow) vs a DF of 100 which is very light but needs a very fast stroke to see any wattage).

If all other conditions are similar (state of tiredness/exertion etc) then the should be very little, if any, difference between machines set at the same DF - unless as Carl says the PM is not set for the correct model.

[Nomath]

... When I'm home and rowing hard I get the watts reading up to the low 200's and don't think I ever get over 230 watts. Talking to my trainer at the gym and she mentioned seeing other rowers watts outputs in the 300-400 range. I got on the rower at the gym and also showed watts in the high 300's...

This is a very interesting observation and worth further investigation!

If, as previous replies suggest, the gym rower is clogged by dust and dirt, this only means that its drag factor is much lower for the same damping setting due to reduced air circulation. However, the basic principle of all C2 ergs is that no matter how you set the DF, it measures the applied power accurately. The same applies for changes in altitude, barometric pressure, temperature, etc. That's why it is called an ergometer.

Ergometers measure what your body is capable to deliver.
A lower DF would certainly give a different feel at the handle. During the recovery the flywheel drops less in speed, so it takes a bit longer to connect with the flywheel after the catch (catch slack). Your speed in the drive phase will be higher and the rating will be higher for the same wattage.
You can get the same sensations on your home erg with a lower damper setting.

I suggest that you do a 1000 m exercise on both ergs at the same damper setting. If, at the same perceived effort, the average power over that distance differs by more that 15%, or pace differs by more that 5%, the result would be truely sensational.

[Citroen]

I suggest that you do a 1000 m exercise on both ergs at the same damper drag factor setting. If, at the same perceived effort, the average power over that distance differs by more that 15%, or pace differs by more that 5%, the result would be truely sensational.

FTFY, you're welcome.

[joelsmartin]

Thanks for all the replies. Not at the gym again until next week but will look at the DF then. I like the idea of a 1000m row on each for comparison. Gonna do some a/b testing on this one as I'm very curious.

[Carl Watts]

Some of the PM monitors are now faulty.

Basically unless it has a newer PM5 on it, the results are not trustworthy. Plenty of Gyms still using PM3's made back in 2003, they are now to old and have corrosion on the board that can give all sorts of incorrect readings.

Basically all the rowers came out of the C2 factory identical in the Wattage reading, over time the rowers deteriorate and the results will vary.

[jamesg]

Talking to my trainer at the gym and she mentioned seeing other rowers watts outputs in the 300-400 range.

All my coaches were men. Never saw an effect like that.

[Carl Watts]

Talking to my trainer at the gym and she mentioned seeing other rowers watts outputs in the 300-400 range.

All my coaches were men. Never saw an effect like that.

Probably looking at the Calories instead of the Watts ???

[Nomath]

I suggest that you do a 1000 m exercise on both ergs at the same damper drag factor setting. If, at the same perceived effort, the average power over that distance differs by more that 15%, or pace differs by more that 5%, the result would be truely sensational.

FTFY, you're welcome.

Citroen, I definitely wrote and meant damper setting !

There have been scientific investigations in the past about the effect of the drag factor on performance. I discussed such an investigation in another topic some time ago. The figure below is from that study. Ergs were set at DF=100 and at DF=150. Participants were asked to row 7 stages of 3 minutes ; 1 minute rest in-between. At each stage the intensity increased. The last stage was going all-out over 3 mins. The result was that there was no significant effect of the drag factor on the wattage. There is however an effect of DF on stroke rate and on heart rate.
Hence there is no need to compare the gym erg and home erg at the same drag factor.

[JaapvanE]

Hence there is no need to compare the gym erg and home erg at the same drag factor.

On brand new or competition-approved machines, you're probably right. If only people treated rowers with the respect they deserve.

In my observation, gyms tend to equate the term "low maintenance equipment" with "no maintenance neccesary". At my local gym, damper 10 actuallt means a drag of 110 (yeah, I pointed them to the excellent maintenance part of Concept2's website). So comparing two random C2's based on damper setting is meaningless IMHO. It does have the positive side-effect that people will never hurt themselves by setting a damper 10....

And there is a huge difference there: in a gym I visit there is a young model D/PM5 where I can row 8:00 on a 2K at drag 133 easily, at home on my brand new RowErg I'm struggling to get 8:40 at drag 133 (also roughly same damper setting). It can come down to not being placed on a perfectly flat surface (tilting the machine forward can have surprising effects), machine maintenance, airflow, etc.

The only way to identify if a rower with those kind of issues is by comparing drag factor and seeing what the difference is.

[Tsnor]

Interesting, and surprising.

Concept2's ranking system, record systems, crash-b's etc. are all based on 'any erg at any DF will give the same wattage/split time results because the erg is recalibrated with each stroke based on the spin down rate of the known-mass flywheel.'

There don't appear to be unexpected split time differences between any of the 20 or so club ergs we have, dirty or clean. The same people end up in the same relative rowing strength order regardless of which erg they grab. The erga are stored vertically standing on their fan housings. Rowers take the next one they see with a pm5, then start taking those with a PM3, so rowers are not using the same machine each time.

Imagine impact on college recruiting if coaches thought prospective rowers might be using a "golden erg" that would take their 6:15 2K time down to 6:02...

[Carl Watts]

I think you guys are overestimating the differences between machines.

You simply don't make big performance gains without jumping from a static erg to then mounting it on slides.

The rower self calibrates stroke by stroke so there actually has to be something wrong with the monitor and to a lesser extend the condition of the rower mechanically to get a significant variation.

As stated before if you had a line of brand new Erg machines at a race venue they are identical or put another way, far more "Identical" to a bunch of people on different bikes for example.