Optimal drag factor vs demographics data?

[mf11]

i think a good simplified analogy i have seen regarding drag factor is imagine you are lifting dead weights and you need to lift 10000kg.

1 lift of 100kg = 100kg
2 lifts of 50kg = 100kg

so you can either lift 100kg 100 times, or 50kg 200 times. what weight will allow you to get to 10000kg quickest?

a very high drag factor is like lifting 100kg. a very low drag factor is like lifting 50kg.

finding the optimum weight depends on your technique.

if you are a big guy with less aerobic ability but more strength you may prefer a slightly higher drag for optimal performance. or if you have less strength but more aerobic ability you may prefer a slightly lower drag factor.

another factor to consider is your distance you are aiming for. if its short distance, aerobic ability maybe less crucial so a high drag factor yields better results. if youre rowing over a longer distance, a lower drag factor might yield better results.

the best way to find out your optimum given your weight/strength, aerobic ability and the distance you are covering, would just be trial and error.

but as a general rule:

heavier, stronger, shorter distances = slightly higher drag factor.
lighter, fitter (aerobic wise), longer distances = slightly lower drag factor.

[Alissa]

Try a drill where you vary the drag factor but maintain time & rate. See for yourself what difference the drag factor makes.

Start with the damper setting that represents your usual drag factor for the time you've selected (in this example, 30 seconds), and note your rate. That's the rate you want to maintain for each of the other segments. Then move the lever up the damper scale by one, maintaining your rate. Keep moving up the scale until you've done a segment at damper setting 10. Then move down the scale, until you reach the bottom of the scale, still maintaining your rate. Then move back up the scale until you reach the damper setting you started with. It will take you 10 and a half minutes to complete the drill.

If you want to make each segment longer you could move the damper settings by two as you move up and down the scale.

Just an idea.

Alissa

[wahoodave]

I came across this thread while searching for drag factor info. On another thread, an engineer posted a rationale for why drag factor depends on the individual. As an engineer, that made sense to me. Previously, I had been using a low drag factor of about 110 but have found that, for me, a drag factor of 125 gives me a more efficient row. BTW - I'm 5'6" and 60 years old with about 5M meters under my belt. I think everyone should experiment to find their optimum and that optimum will likely vary depending on the distance rowed. That's my take away from the preceding discussion.

[finnreams]

Charley Butt, the Harvard rowing coach, said that the most realistic drag factor to simulate rowing in the water is 105. On my erg, 105 is around 4.

[NavigationHazard]

To quote myself from a 2009 thread on the subject:

... the speed of a hull through the water is a function of wetted surface area (how much hull is in the water), hull drag (depends mainly on hull cross section), laminar flow (how long the flow over the hull stays smooth before inevitably becoming turbulent), and wave drag. All of these vary according to rower weight, boat type and specific hull design, potentially considerably. Thus there is no easy correspondence between the 'feel' of a boat OTW and drag factor on a C2 erg. It depends on the rower, the type of boat s/he is rowing, and the specific manufacturer's design.

A FLW 1x jr sculler looking to emulate her boat's feel, for example, is highly unlikely to want the same DF as the 200-lb + Rob Waddell in a heavyweight Empacher. And neither are going to be anywhere close to a damper setting of 10 on a new machine/DF ~200.

[gregsmith01748]

Hi,

The best data that I have seen on this in an issue of the biorow newsletter.

http://www.biorow.com/RBN_en_2011_files ... News01.pdf

And it goes a bit further in this one:
http://www.biorow.com/RBN_en_2011_files ... News06.pdf

Basically, it depends on the kind of boat you are trying to train for. The numbers in there are substantially lower.

For a world class 8+, the drag factor equivalent is 86. I assume that a slower boat would correspond to a higher drag factor since the oars would be moving through the water more slowly.

[NavigationHazard]

In the 2011 Biorow #1, Kleshnev's assumption of 550 watts for 2000m in Table 1 equates to a 5:44 erg 2k for a single sculler. There might be half a dozen of those in an Olympic year (all MHWs, I might add). I think Synek's best erg time is something like 5:42.6, for example.

I think most ordinary mortals are going to want to add some resistance to Kleshnev's recommendations if they're trying to emulate boat drag on an erg. Mileage may vary, of course, for reasons already alluded to, plus one I forgot: gender. This has a lot to do with biological differences in % and distribution of lean muscle mass.

FWIW, a number of national programs specify drag factors for erg tests. In 2013, for example, Row Canada adopted a set of recommendations that look like:

Junior, LW and Open Women DF 110;
Junior and LW Men 120;
Open Men 130.

Those are 1) not boat-specific and 2) much higher than Kleshnev's suggestions. Who knows how closely they approximate actual boat drags for the various classifications. But I assume that the selectors were not being entirely capricious in setting them....

See http://rowingcanada.org/sites/default/f ... 3_2016.pdf

[gregsmith01748]

The thing I don't get is why open men would be higher than others, I would have thought the opposite.

[hjs]

The thing I don't get is why open men would be higher than others, I would have thought the opposite.

Open man have the strongest stroke, if the drag would be very low, the stroke time would be to short. And although the slow boat, high drag and fast boat, low drag makes some good sence. Its not just the boat type, but also the rowers. Faster rowers are not just faster, but roughly also stronger, so the can handle a bit more drag.

[gregsmith01748]

As I thought about it more, I started to come to the same conclusion. Basically, that open weight men will row with the boat more heavily geared (longer oars, less inboard) so that the pressure on the oar handle is greater and handle speed will be lower. This essentially is like upping the drag factor on the erg.

That's the factor I was missing.