Concept2 Forum

I was just curious whether the energy required to achieve faster paces on the erg varies in a linear or in some sort of exponential relationship. I guess what I'm thinking of is that in a boat (kayak for certain, and I imagine a rowing shell as well) there is a relatively linear relationship between force applied and speed up to a certain point (determined by the hull shape), and then it becomes exponentially more difficult to achieve higher speeds. Is anything like this "built into" the C2, or is the difference in force the same from 1:38-1:40/500 as from for example 1:58-2:00/500?<br /><br />I hope this question makes sense.<br /><br />Andrew

The watts you are required to produce to go faster does not go up in a linear relationship. I don't have the formula handy and don't really know it, but this a chart I did from a full watts to pace conversion chart (I think on the C2 site somewhere here or in the UK).<br /><br />1:35 pace=408 watts<br />1:40 pace=350 watts<br />1:45 pace=302 watts <br />1:50 pace=263 watts<br />1:55 pace=230 watts<br />2:00 pace=203 watts<br />2:05 pace=179 watts<br />2:10 pace=159 watts<br />2:15 pace=142 watts<br />2:20 pace=128 watts<br />2:25 pace=115 watts<br />2:30 pace=104 watts

<!--QuoteBegin-afolpe+Oct 28 2005, 03:01 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(afolpe @ Oct 28 2005, 03:01 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->I was just curious whether the energy required to achieve faster paces on the erg varies in a linear or in some sort of exponential relationship. </td></tr></table><br /><br />It's exponential - the exponent in question being 3.<br /><br />To overcome air resistance, doubling the speed requires 8 times (2 to the 3rd) the power. So a 1:00 pace would require 8x the power of a 2:00 pace, which is literally superhuman.<br /><br />More than you probably want to know about this can be found at <a href='http://www-atm.physics.ox.ac.uk/rowing/ ... meter.html' target='_blank'>The Physics of Ergometers</a>.

Thanks- the watt numbers are very interesting. Haven't had time to read the article yet, so excuse me if the answer is in there- would it make any difference what volume of air was being moved during the stroke, ie, the damper setting? I guess this would be easy enough to test, rowing the same pace at different damper settings and seeing what the watts are.<br /><br />Andrew

<!--QuoteBegin--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Haven't had time to read the article yet, so excuse me if the answer is in there- would it make any difference what volume of air was being moved during the stroke, ie, the damper setting? </td></tr></table><br /><br />No matter where the damper is set you are still moving air, so the same cubic speed to power relationship applies.<br /><br />Actually, this relationship holds for all fluids, so you could row your erg underwater (where the drag factor would be astronomical) and it would still be true.

<!--QuoteBegin-afolpe+Oct 28 2005, 08:29 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(afolpe @ Oct 28 2005, 08:29 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Thanks- the watt numbers are very interesting. Haven't had time to read the article yet, so excuse me if the answer is in there- would it make any difference what volume of air was being moved during the stroke, ie, the damper setting? I guess this would be easy enough to test, rowing the same pace at different damper settings and seeing what the watts are.<br /><br />Andrew <br /> </td></tr></table><br /><br />Indeed, that will not make any difference. What the PM2 or PM3 does is measuring the speed variation during stroke and recovery. In a very ingenious way, this is used to calculate the power (Watt's) you apply. This power is used to calculate the pace. This last calculation is somewhat artifical: your erg is not moving so there is no pace. <br />However: the power you apply IS real. The pace that is show on the monitor is the pace you would reach when four "you's" are applying this power in a real boat and these four people are well-skilled and trained oarsmen. <br /><br />Tom<br />