Difference in performance after a service

[simon@mckieandco.com]

I recently had my Model D Concept 2 Rower serviced for the first time since I bought it roughly ten years ago. The chain, tooth sprocket and shock cord were replaced. Its drag factor at level ten improved from about 160 to about 210. I have found, however, that even at the setting which gives a drag factor of 160 (I had always previously had it set at the highest level), and indeed at other drag factors, my times and distances are reduced. So for example my distances for a 40 minute row have reduced from 10,400m-10,550m to 10,200m-10350m. The stroke seems more difficult in the last half than it did before the service. Is there any reason why this should be so? Is there something that I might be doing wrong. My wife has also experienced the same thing, her distances for 30minutes reducing from 6400m-6550m to 6300m-6425m.

I sent a question and some photographs to Concept2. Their comments were:

'Thank you for supplying the photos of the recently serviced indoor rower. I have to say I cannot see anything wrong at all, and this may be a case of the time/distances you were achieving were not quite correct since the performance feedback was not up to standard, and the machine may have been a little more forgiving due to worn parts in certain areas.

I am sorry that I cannot provide a more in- depth explanation, but as I said there is no issue from a correctly assembled machine view point.'

I was impressed by their willingness and speed at answering my questions but I'm a little puzzled. I thought the computer adjusted for differences between machines through the drag factor. Also, if that's not the case, how are machines equalised for competition?

[Citroen]

There's very little difference between 10500 (238.1 Watts) and 10200 (215.5 Watts) that can't be explained away by hydration, ambient temp, time of day, nutrition levels of the warm (or warmer) body on the seat.

The main thing a serviced ergo is going to have much tighter cords (and cord tightness isn't measured by the PM3). If they are too tight that can have a really detrimental effect. At full extent there should be about 6-8lbs of pull on the chain (you can measure that with a fishing scale) [Sorry I should give that force as Newtons, the ISO police should have an arrest warrant out for me]. They may need slackening off a little.

[hjs]

There's very little difference between 10500 (238.1 Watts) and 10200 (215.5 Watts) that can't be explained away by hydration, ambient temp, time of day, nutrition levels of the warm (or warmer) body on the seat.

The main thing a serviced ergo is going to have much tighter cords (and cord tightness isn't measured by the PM3). If they are too tight that can have a really detrimental effect. At full extent there should be about 6-8lbs of pull on the chain (you can measure that with a fishing scale) [Sorry I should give that force as Newtons, the ISO police should have an arrest warrant out for me]. They may need slackening off a little.

For an long time erger those differences are not small Doug.

If the op an, try an other erg and see if you pull better results there.

Re drag, way to high, you use a slow stroke.

[jackarabit]

Very good question re: calibration of machines for competition. Is calibration possible? Seen a device for calibration? Heard about one? There is Doug's fish scale for equalizing shock cord tension. The explanation the last time this came up was that new machines are provided at major comps and all of a batch should be all of a match, right? Right. Very scientific!

But not entirely reassuring considering that somewhere in the hinterlands there's a comp where the ergs are not all of a batch or from a single YOM or with the same milage or maintenance. This is reality. Is the magnitude of variation in performance measurement significant! Who knows? Jack

[Carl Watts]

Your drag factor setting your using is way too high.

With a clean Erg try moving it down to lever position 6 and get something more like 130 on the PM3 monitor to start off with, even this is high for the majority of users.

Whats your typical rating or SPM ?

[simon@mckieandco.com]

Dear hjs, jackrabbit and citroen,

Thank you for your very helpful replies. I apologise for not doing so earlier.