Model C vs Model D

ancho · Post by **ancho** » March 16th, 2006, 12:39 pm

I got my own erg (Model D) on january.
Last monday I did a WP Level 1 4*1000 on a model C in the gym I used to erg before.
I found the model C to go quite easier, and achieved better splits than I use to at home.
Is it the erg or is it me??

Any experiences on this?

Godfried · Post by **Godfried** » March 16th, 2006, 2:30 pm

Did you use the same drag factor on both?

I have used a few C's at the gym, and on one of them was faster than on the other, but it might be I just liked that one better.

John Foy · Post by **John Foy** » March 16th, 2006, 2:32 pm

I have heard many people mention this. I would say the Model c is much easier to reach a certain split. I wonder what this means for World records set on C's with a PM2

PaulS · Post by **PaulS** » March 16th, 2006, 3:07 pm

John Foy wrote:I have heard many people mention this. I would say the Model c is much easier to reach a certain split. I wonder what this means for World records set on C's with a PM2

Nothing. AFAIK the maths are identical for the PM2 and PM3.

We have an acid test for just this thing. ErgMonitor, which is independent of the PM2 or PM3, produces results which are pretty much identical to either of the PM's when being used simultaneously.

I did have a chance to hook up a PM2 and PM3 to a Model B simultaneously and it appeared there was the occassional 0.1 second difference in overall time, perhaps they sense the first stroke differently. I know that ErgMonitor starts the time slightly faster than both PM's, but it also begins counting meters more quickly so the reason for the similarity overall is obvious.

In other words:
Ergmonitor = PM2 and
Ergmonitor = PM3 therefore
PM2 = PM3

Any difference is completely perceptual, and perceptions can be very powerful influences, just close your eyes and try to hold the exact same pace you were on steady for 50 strokes and see what it says when you open them.

johnlvs2run · Post by **johnlvs2run** » March 16th, 2006, 4:19 pm

The question is if there is a difference between the model C and model D as to times, not the pm2 or pm3.

The model D has a gasket around the cogwheel, that may provide more resistance to the chain.

Also it has a magnetic generator, to store energy for the monitor. This might slow down the flywheel, faster than it would without the magnetic resistance.

PaulS · Post by **PaulS** » March 16th, 2006, 5:04 pm

John Rupp wrote:The question is if there is a difference between the model C and model D as to times, not the pm2 or pm3.

The model D has a gasket around the cogwheel, that may provide more resistance to the chain.

Also it has a magnetic generator, to store energy for the monitor. This might slow down the flywheel, faster than it would without the magnetic resistance.

That's a good point about the new dampened cog, as the PM would not be able to account for that, just like a stiff chain could cause additional resistance. Perhaps C2 could address that, as it would seem that the dampened cog would not cause any additional resistance. Or do you have an idea as to why it might? People who have upgraded their C's with the dampened cog would also be a source of verification, if they felt their C got "harder" after the change.

The magnetic resistance of the generator would be accounted for in the DF calculations, so should have no effect on this.

Having rowed alternately on a C and D for some time, I never noticed a particular difference in effort for a given pace, and with report from others going both directions, i.e. some have thought the D to be easier, it's quite easy to conclude what I have already said regarding perception. Perception is reality after all. 8)

FrankJ · Post by **FrankJ** » March 16th, 2006, 9:11 pm

PaulS wrote: That's a good point about the new dampened cog, as the PM would not be able to account for that, just like a stiff chain could cause additional resistance. Perhaps C2 could address that, as it would seem that the dampened cog would not cause any additional resistance. Or do you have an idea as to why it might? People who have upgraded their C's with the dampened cog would also be a source of verification, if they felt their C got "harder" after the change.

The magnetic resistance of the generator would be accounted for in the DF calculations, so should have no effect on this.

Having rowed alternately on a C and D for some time, I never noticed a particular difference in effort for a given pace, and with report from others going both directions, i.e. some have thought the D to be easier, it's quite easy to conclude what I have already said regarding perception. Perception is reality after all. 8)

I put a quiet kit on my Model C which is the new dampened cog and it had no noticeable affect on either Yvette's or my times.

I also have both a PM2 and PM3 on my erg and at one time reported a problem with significant differences in times for distances over 10K. They did a firmware update to the PM3 and that corrected the problem. When it was failing the PM3 would display a pace that was up to a couple of seconds faster or slower than the PM2. What level of firmware do you have on your PM3 Ancho?

Frank

PaulS · Post by **PaulS** » March 16th, 2006, 9:42 pm

FrankJ wrote: I put a quiet kit on my Model C which is the new dampened cog and it had no noticeable affect on either Yvette's or my times.

I also have both a PM2 and PM3 on my erg and at one time reported a problem with significant differences in times for distances over 10K. They did a firmware update to the PM3 and that corrected the problem. When it was failing the PM3 would display a pace that was up to a couple of seconds faster or slower than the PM2. What level of firmware do you have on your PM3 Ancho?

Frank

Thanks Frank, I kind of figured there would be some confirmation by someone like you. I think grams did the quiet kit also, but she's cyling around the countryside at the moment.

With your PM2/PM3 testing, what kind of time differences over 10K did you see?
If the PM3 was going a particular direction (faster/slower) did it stay that way for the entire workout or swap, ending up balancing out in the end?

Cheers.

FrankJ · Post by **FrankJ** » March 17th, 2006, 6:58 am

PaulS wrote: Thanks Frank, I kind of figured there would be some confirmation by someone like you. I think grams did the quiet kit also, but she's cyling around the countryside at the moment.

With your PM2/PM3 testing, what kind of time differences over 10K did you see?
If the PM3 was going a particular direction (faster/slower) did it stay that way for the entire workout or swap, ending up balancing out in the end?

Cheers.

Hi Paul,

Actually I first noticed the problem during a marathon where the difference was 20 seconds slow. It varied though with another marathon actually being about 40 seconds faster. On my equipment the problem would just start showing up at about the 40 to 60 minutes of rowing. I would first notice that the PM3 would be a little faster or slower than the PM2. In some of the cases it would change from slower to faster during the row. If we had the old forum active I could give you the firmware version that I was using at the time.

Frank