Drag Factor Survey

[[old] Galt]

Hi gang and happy hollidays.<br /><br />I am trying to get a good comparison of drag factor vs. damper setting here in Boulder vs. at sea level.<br /><br />I would appreciate it if some of you sea level ergers would let me know what your drag factors are with the damper set at 3, 6, and as high as it will go.<br /><br />On my model D here the factors are 75, 104, and 140.<br /><br />We are at 5300 feet and the air, especially this time of year, is bone dry.<br /><br />Thanks much for your input.

[[old] PaulS]

<!--QuoteBegin-Galt+Dec 5 2005, 01:57 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(Galt @ Dec 5 2005, 01:57 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Hi gang and happy hollidays.<br /><br />I am trying to get a good comparison of drag factor vs. damper setting here in Boulder vs. at sea level.<br /><br />I would appreciate it if some of you sea level ergers would let me know what your drag factors are with the damper set at 3, 6, and as high as it will go.<br /><br />On my model D here the factors are 75, 104, and 140.<br /><br />We are at 5300 feet and the air, especially this time of year, is bone dry.<br /><br />Thanks much for your input. <br /> </td></tr></table><br /><br />Is your machine well maintained? Those seem very low.<br />Redmond, WA USA (<500ft), Pretty dry in the house, but perhaps not quite as dry as where you are.<br />3 - 105 w/CBreeze, 112 bare.<br />6 - 135 w/CBreeze, 145 bare.<br />Max - 175 w/CBreeze, 220 bare.

[[old] adkmurray]

<!--QuoteBegin-Galt+Dec 5 2005, 05:57 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(Galt @ Dec 5 2005, 05:57 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Hi gang and happy hollidays.<br /><br />I am trying to get a good comparison of drag factor vs. damper setting here in Boulder vs. at sea level.<br /><br />I would appreciate it if some of you sea level ergers would let me know what your drag factors are with the damper set at 3, 6, and as high as it will go.<br /><br />On my model D here the factors are 75, 104, and 140.<br /><br />We are at 5300 feet and the air, especially this time of year, is bone dry.<br /><br />Thanks much for your input. <br /> </td></tr></table><br /><br />Model D at 1700', 3= 101, 6= 140, 10= 197<br />Not at sea level but hope that helps. Quite a difference?<br />Jim

[[old] Galt]

I should have been clearer that the biggest difference is the altitude. Much less air resistance up here.<br /><br />Yes this helps a bunch.<br /><br />I'd appreciate some confirmation of the numbers.<br /><br />Thanks!

[[old] John Rupp]

<!--QuoteBegin-Galt+Dec 5 2005, 03:09 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(Galt @ Dec 5 2005, 03:09 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->I should have been clearer that the biggest difference is the altitude.  Much less air resistance up here.[right] </td></tr></table><br /><br />Yes that's why the times are so much faster at altitude.<br /><br />The range on my model C is 98 to 215.<br /><br />When I put it in the middle of the garage then the highest reading goes up to 235.<br />

[[old] Galt]

Not sure to what times you refer. Erg times at altitude are substantially slower. C2 uses an adjustment factor of about 3% to compensate for the detrimental effect of altitude on erg performance.<br /><br />We get no benefit from the lower air resistance (other than an easier slide up and down the rail) as it is compensated for by a lower drag factor.<br /><br />ty.<br /><br />

[[old] Bayko]

Two year old Model D, sea level.<br /><br />Damper 3 = 100 drag<br /><br />Damper 6 = 140 drag<br /><br />Max Damper = 197<br /><br />Another variable seems to be humidity. This past summer I left the Damper setting on 4 and the drag varied from 123 on the driest days to 114 on the most humid.<br /><br />Rick

[[old] Bayko]

<!--QuoteBegin-John Rupp+Dec 5 2005, 11:31 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Dec 5 2005, 11:31 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><!--QuoteBegin-Galt+Dec 5 2005, 03:09 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(Galt @ Dec 5 2005, 03:09 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->I should have been clearer that the biggest difference is the altitude.  Much less air resistance up here.[right] </td></tr></table><br /><br />Yes that's why the times are so much faster at altitude.<br /><br />The range on my model C is 98 to 215.<br /><br />When I put it in the middle of the garage then the highest reading goes up to 235. <br /> </td></tr></table><br /><br />In the European Championships last Saturday two altitude residents, Dennis Hastings and Bob Spengler broke the world records for their age groups when they competed at sea level.<br /><br />Just imagine how much faster yet these two would be if they decided to stop sandbagging it at altitude, as John Rupp suggests, and let loose a good effort at home.

[[old] c2jonw]

And don't forget temperature. A model D in our workout room (68 F) has a df of 82-201. I just took it outside (28 F) and the range went to 91-221. JonW

[[old] R S T]

<!--QuoteBegin-Bayko+Dec 6 2005, 12:09 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(Bayko @ Dec 6 2005, 12:09 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><!--QuoteBegin-John Rupp+Dec 5 2005, 11:31 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Dec 5 2005, 11:31 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><!--QuoteBegin-Galt+Dec 5 2005, 03:09 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(Galt @ Dec 5 2005, 03:09 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->I should have been clearer that the biggest difference is the altitude.  Much less air resistance up here.[right] </td></tr></table><br /><br />Yes that's why the times are so much faster at altitude.<br /><br />The range on my model C is 98 to 215.<br /><br />When I put it in the middle of the garage then the highest reading goes up to 235. <br /> </td></tr></table><br /><br /><br /><b>Just imagine how much faster yet these two would be if they decided to stop sandbagging it at altitude, as John Rupp suggests, and let loose a good effort at home</b>. <br /> </td></tr></table><br /><br />Hilarious. Nice one Bayko.<br /><br />

[[old] mpukita]

<!--QuoteBegin-Galt+Dec 5 2005, 07:38 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(Galt @ Dec 5 2005, 07:38 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->Not sure to what times you refer.  Erg times at altitude are substantially slower.  C2 uses an adjustment factor of about 3% to compensate for the detrimental effect of altitude on erg performance.<br /><br />We get no benefit from the lower air resistance (other than an easier slide up and down the rail) as it is compensated for by a lower drag factor.<br /><br />ty. <br /> </td></tr></table><br /><br />Not to be uncharitable, but this is not true in "John's World", where everything is backwards and upside down. Just search on his login name and read his past posts. You'll see ...

[[old] Galt]

Thanks gang.<br /><br />Rick, I am surprised by your experience because I would expect drag factor to increase with humidity. <br /><br />If anybody knows of any reason why it would go the other way pleease let me know.<br /><br />

[[old] c2jonw]

We've never run any controlled tests on this, but I would also think that, if anything, the df would go up with increased humidity. I wonder if those humid days Rick mentioned were warmer than the dry days.......Rick??<br /><br />JonW

[[old] PaulS]

<!--QuoteBegin-c2jonw+Dec 6 2005, 08:00 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(c2jonw @ Dec 6 2005, 08:00 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->We've never run any controlled tests on this, but I would also think that, if anything, the df would go up with increased humidity. I wonder if those humid days Rick mentioned were warmer than the dry days.......Rick??<br /><br />JonW <br /> </td></tr></table><br /><br />That does seem intuitive, and I could well be mis-remebering, but someone more expert in chemical/gas properties mentioned that water vapor was less dense (examples of steam rising, clouds, etc...) meaning that as humidity rose, air density decreased, air induced drag (DF) goes down. It all made perfect sense then.

[[old] John Rupp]

<!--QuoteBegin-c2jonw+Dec 6 2005, 04:33 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(c2jonw @ Dec 6 2005, 04:33 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->And don't forget temperature. A model D in our workout room (68 F) has a df of 82-201. I just took it outside (28 F) and the range went to 91-221. JonW[right] </td></tr></table><br /><br />Yes temperature makes a big difference. <br /><br />The DF always goes down during my sessions, as the temperature goes up.<br /><br />Humidity doesn't seem to make much of a difference though.