Dynamic vs Stationary

[Rockin Roland]

Or to sum up my last post, no rowers do NOT "pull their own weight." They have to move their own weight plus their share of their boat's weight plus their share of a coxswain's weight if the boat has one. Oddly enough, on a static erg rowers actually do have to shift precisely their own weight.

On the water, rowers also have to pull the weight of other rowers in the boat that are heavier than them because, despite their extra weight, they don't offer any advantage due to their poorer power to weight ratios.

Nav, your a big guy, around 118 kg. At that size it must be hard for you to get a seat in a competitive crew. And that's without even bringing percentage of body fat levels into the equation. Too much drag on the boat for what you could possibly offer in return to a fit strong crew that otherwise would average around 90kg. Over here power to weight combined with technique is the key to going fast on the water. For this reason quality rowers that are very lean, long limbed and strong avoid rowing with blokes of your size. My apology for using you as an example because of your size. I would imagine that would happen over there too.

On a static erg, in effect you are bolted to the planet and push against a foot plate that doesn't move. Hence a guy of your size who can put his weight behind the handle would have an advantage over a lighter guy with the same level of fitness. However, on a dynamic erg, because you have to move with the system under you, size becomes less of an advantage but still not to the same degree as on the water.

[NavigationHazard]

On the water, rowers also have to pull the weight of other rowers in the boat that are heavier than them because, despite their extra weight, they don't offer any advantage due to their poorer power to weight ratios.

This is not necessarily the case. Consider my LW wife rowing 1) a 2x with her LW veteran woman double partner and 2) rowing a 2x with Nathan Cohen. Leaving aside the fact that Cohen wouldn't fit in a LW 2k and they'd need a bigger boat, he'd still provide a far faster ride despite a poorer power/weight ratio. Absolute power trumps ratio, if there's enough power. There's also a skill factor involved: you have to be able to translate individual power into boat movement; you also have to be able to synchronize what you're doing with other rowers such that you collectively achieve the maximum you're capable of.

As for what I might possibly offer a competitive crew in terms of potential power vs. weight, you're forgetting masters' categories. Assuming I weigh 118 kgs, my weight-adjusted 6:25.6 erg 2k in 2010 (best in the rankings last year) is a 6:22.4. That's the same as a weight-adjusted 6:49.5 for a 90kg rower of the same age. Precisely 15 other rowers aged 55 or older ranked anything better than a 6:49.5 last year. The odds of finding eight 90kg male category D/56 yr olds (for handicap purposes) in the same club with at least 6:49.5 erg scores are zero. I doubt there's a club anywhere that has more than one or two, and that would be someplace like Tideway or Leander where former Olympians like Ian McNuff hang out. Moreover I do rather better comparatively at the 1k masters' sprint distance.

I might or might not be a boatstopper. But at the masters' level I'm absolutely competitive in terms of power-to-weight.

None of this should obscure the fact that Rupp was wrong about who's shifting what.

[johnlvs2run]

None of this should obscure the fact that Rupp was wrong about who's shifting what.

I thought you were proving I was right.

[Bob S.]

[However, on a dynamic erg, because you have to move with the system under you, size becomes less of an advantage but still not to the same degree as on the water.

Roland,

I don't get your point there about less advantage on the dynamic. It seems to me that weight would be more of a disadvantage on the static, because there is more weight done accelerating and decelerating the body mass on a static than on a dynamic. On the water, it is a different matter.

Bob S.

[Carl Watts]

[However, on a dynamic erg, because you have to move with the system under you, size becomes less of an advantage but still not to the same degree as on the water.

Roland,

I don't get your point there about less advantage on the dynamic. It seems to me that weight would be more of a disadvantage on the static, because there is more weight done accelerating and decelerating the body mass on a static than on a dynamic. On the water, it is a different matter.

Bob S.

Correct the bigger you are the bigger your advantage is going to be on the Dynamic over the Static.

You are no longer having to move your own mass, only that of the dynamic part of the Erg so the playing field is now even. What becomes more important is an efficient or "Correct" technique, however you want to put it. It appears that the Dynamic penalises you for incorrect technique with Erg scores lower than you may get on the Static.

Also from what I hear a little extra weight on the water makes little difference, so you sit a couple of mm lower in the water, ultimatly the boat speed is limited by it's length and the power your putting in. Your ability as a rower has the ability to triumph over a few extra kilo's.

[Bob S.]

[However, on a dynamic erg, because you have to move with the system under you, size becomes less of an advantage but still not to the same degree as on the water.

Roland,

I don't get your point there about less advantage on the dynamic. It seems to me that weight would be more of a disadvantage on the static, because there is more weight done accelerating and decelerating the body mass on a static than on a dynamic. On the water, it is a different matter.

Bob S.

I see that I made a gross typo. That should have been "more work done." By the time I spotted it, it was too late to edit it.

Bob S.

[Rockin Roland]

As for what I might possibly offer a competitive crew in terms of potential power vs. weight, you're forgetting masters' categories. Assuming I weigh 118 kgs, my weight-adjusted 6:25.6 erg 2k in 2010 (best in the rankings last year) is a 6:22.4. That's the same as a weight-adjusted 6:49.5 for a 90kg rower of the same age. Precisely 15 other rowers aged 55 or older ranked anything better than a 6:49.5 last year. The odds of finding eight 90kg male category D/56 yr olds (for handicap purposes) in the same club with at least 6:49.5 erg scores are zero. I doubt there's a club anywhere that has more than one or two, and that would be someplace like Tideway or Leander where former Olympians like Ian McNuff hang out. Moreover I do rather better comparatively at the 1k masters' sprint distance.

I might or might not be a boatstopper. But at the masters' level I'm absolutely competitive in terms of power-to-weight.

Nav,
There's never any doubt that your a very powerful guy for your age. If your weight adjusted score of 6:25 from 6.22 is only 3 seconds for a 118kg bloke on a C2 erg then I have absolutely no faith in the C2 system of measuring people on their ergs. On a Rowperfect erg, scores are automatically adjusted and I'm sure that you would not fare so well. As you know I'm not a big fan of using static C2 ergs for measuring boat moving ability anyway. However, our club has 3 blokes over 50 that will go under 6:55 (which includes me sub 6:30) all 95 kgs or less. There are another two clubs in our area that have 2 or more over 50s 95 kg or less blokes capable of sub 6:55. None of us have any interest whatsoever in logging scores in the C2 rankings. That would explain why you only have 15 blokes logged. C2 rankings are far from definitive.

On the water, static erg scores mean far less. Assuming technical ability is equal. Put a 118 kg bloke in a coxless four with three fit strong 90kg blokes, rather than four 90 kg blokes, and even before you take the first stroke the boat already is sitting lower in the water creating more drag. That 118kg bloke would need to generate considerably more power than the other guys to negate the extra 28 kg penalty he is imposing on them with that extra drag through the water. Even if he could do that then you still have the problem of uneven pressure on one side of the boat from the 118kg guy, causing balance and steering issues.

[Rockin Roland]

Correct the bigger you are the bigger your advantage is going to be on the Dynamic over the Static.

That's incorrect. On a dynamic erg you have a so called level playing field. Everyone is equal because they have to move their own mass on a sliding system. Unlike a static erg where one can use their extra weight to get additional leverage against a fixed surface to get more spin on the flywheel. You can't do that on a dynamic erg because there's no fixed surface to hang off. You still have to do the work but the leverage of weight against a fixed surface offers a technical advantage on a static erg which would contribute towards a better score.

[slwiser]

I don't know about all this weight and leverage stuff but here is something that I have read about the static elsewhere. Somewhere it has been stated that the static has an inefficiency of about 15-17 watts compared with cycling. This was suggested as being an inefficiency coming from having to move the weight down and back the rail. I would suggest the Dynamic has less of this inefficiency on the order of 4-5 watts. Therefore the theoretical efficiency gain from the Dynamic should be on the order of 10 watts.

I don't know how this would really relate to the recent previous discussion but this is my take. But here it goes to expose my lack of knowledge. Cardio wise I think this suggests that I should be able to apply an additional 10 watts into the split times but there are problems with this in that the loses from the static inefficiency are very hard to get back. Maybe there are gains from the over-compression and extra extension on the static coming from the inertia movement back and forth giving me a little extra length that over-comes the proposed moving inefficiencies of the static. In my experience this gain is about equal to the moving losses coming back to the Dynamic for a basis. This is why I suggest that the Dynamic is harder to maintain equal split times compared with the static. On my Dynamic I am working on my aerobic base to gain that 10 watts that I think is there. To do this I need to build my muscles that apply forces to the stretcher. This is coming slowly but I think I see it coming.

Bottom line my technique is probably so poor that none of this is even remotely accurate for me but it keeps me thinking and looking for a little less on my split times. Hope springs eternal I guess. I have enjoyed this discussions in this thread.

[hjs]

Correct the bigger you are the bigger your advantage is going to be on the Dynamic over the Static.

That's incorrect. On a dynamic erg you have a so called level playing field. Everyone is equal because they have to move their own mass on a sliding system. Unlike a static erg where one can use their extra weight to get additional leverage against a fixed surface to get more spin on the flywheel. You can't do that on a dynamic erg because there's no fixed surface to hang off. You still have to do the work but the leverage of weight against a fixed surface offers a technical advantage on a static erg which would contribute towards a better score.

? what technical advantage does weight give. I fail to see, If you pull a certain split, you simply pull with a certain power, how big your body is does not matter and a bigger person even does waist more energy in bringing that power (given a same technique).

[hjs]

However, our club has 3 blokes over 50 that will go under 6:55 (which includes me sub 6:30) all 95 kgs or less. There are another two clubs in our area that have 2 or more over 50s 95 kg or less blokes capable of sub 6:55. None of us have any interest whatsoever in logging scores in the C2 rankings. That would explain why you only have 15 blokes logged. C2 rankings are far from definitive.

The rankings are fa far from complete, at our (dutch national) championships I had roughly the 50/60 th overal time, almost non of the people me did rank does times. We have every year roughly 20/25 people going sub 6, but almost never does anyone rank does times.

In Germany, a big rowing country it is the same, at the big indoor regattas the overall level is stronger then Birc/wirc, but most of the times are never ranked.