Difference between static, dynamic & slides erg

[Daniel Spring]

There's been a lot of noise recently with guys setting "world records" on the erg. Eric Murray set the ball rolling with a 14:56 5K set on slides. This was followed up by OUBC releasing a picture of Stan Louloudis's 14:51 5K set on a Dynamic. Today Rowing Australia announced Josh Dunkley-Smith had set a19-29 5K record of 15:10 set on a Static erg.
So with all these different times has anyone actually done an objective evaluation of the different ergs? I think Murray reckoned the sliders were worth up to 2 seconds per 500m v a static but what about the Dynamic and is there any evidence to back this claim up?

[wmar...@gmail.com]

On Friday, 27 November 2015 18:09:13 UTC-5, Daniel Spring wrote:
> There's been a lot of noise recently with guys setting "world records" on the erg. Eric Murray set the ball rolling with a 14:56 5K set on slides. This was followed up by OUBC releasing a picture of Stan Louloudis's 14:51 5K set on a Dynamic. Today Rowing Australia announced Josh Dunkley-Smith had set a19-29 5K record of 15:10 set on a Static erg.
> So with all these different times has anyone actually done an objective evaluation of the different ergs? I think Murray reckoned the sliders were worth up to 2 seconds per 500m v a static but what about the Dynamic and is there any evidence to back this claim up?

2008 or 2009 I was in the building when Rob Waddell did a 14:48 on a static Model D. Didn't actually witness the event but the colleague who did, came upstairs rather dumbfounded...

That said... I don't have an answer to your question except to say that it is subjectively easier to row a higher SR on slides and Dynamic than it is to row on the static machine. The energy demands of rowing a static erg are greater than a moving erg. THAT was shown in 1984* comparing static Gjessing with Gjessing on a wheeled cart. And a C2 on slides, or a RP or a Dynamic are all less demanding the Gjessing on wheels because they're SOOOO much lighter.
*(Martindale and Robertson, Canadian Journal of Applied Sports Sciences, 9:153-163, 1984)

[valery....@googlemail.com]

On Friday, 27 November 2015 23:09:13 UTC, Daniel Spring wrote:
> There's been a lot of noise recently with guys setting "world records" on the erg. Eric Murray set the ball rolling with a 14:56 5K set on slides. This was followed up by OUBC releasing a picture of Stan Louloudis's 14:51 5K set on a Dynamic. Today Rowing Australia announced Josh Dunkley-Smith had set a19-29 5K record of 15:10 set on a Static erg.
> So with all these different times has anyone actually done an objective evaluation of the different ergs? I think Murray reckoned the sliders were worth up to 2 seconds per 500m v a static but what about the Dynamic and is there any evidence to back this claim up?

DIR had the largest inertial efficiency (see 3.1.3) 98.1% at 37 str/min,, compared to a boat (95.3%), slides (91.6%) and stationary erg (82.1%). This allows for higher stroke rate on DIR and, possibly, faster times than on stationary erg. As the speed = power ^ (1/3), DIR should be 5.7% faster than static erg, and C2 on slides should be 3.5% faster than static erg.

[wmar...@gmail.com]

Oh bugger... My bad. Typo. Rob did a 14:58 that day... Sorry.

[nickfishfi...@gmail.com]

This would seem to be pretty applicable: http://www.researchgate.net/profile/Emerson_Franchini2/publication/26767823_Energy_systems_contributions_in_2000_m_race_simulation_a_comparison_among_rowing_ergometers_and_water/links/5444d54c0cf2a76a3ccd9932.pdf

[carl]

What is generally ignored in comparisons like this, & in the setting of
speed targets, is the masking effect of the roughly cubic relationship
between useful (i.e. propulsive) power and actual boat speed. Thus it
takes a 3% increase in propulsive power to make 1% boat sped
improvement, while a 10% speed improvement demands a 33% increase in
propulsive power.

So when we see selection performance targets being set at, say, 97% of
gold medal speed, this demands not that the rower performs at that 97%
but, rather, that their propulsive power need be only 91.3% of that
supposedly required to meet the gold medal standard.

it's disappointing that the Emerson Franchini paper quoted above does
not make a comparison with such as Rowperfect, with its far better
rower:machine mass ratio than the C-II on slides.

Cheers -
Carl

--
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[magnus....@gmail.com]

On Wednesday, December 2, 2015 at 2:33:44 PM UTC, nickfishfi...@gmail.com wrote:
> This would seem to be pretty applicable: http://www.researchgate.net/profile/Emerson_Franchini2/publication/26767823_Energy_systems_contributions_in_2000_m_race_simulation_a_comparison_among_rowing_ergometers_and_water/links/5444d54c0cf2a76a3ccd9932.pdf
>

I read this as showing that, given the error estimates, there's no measurable difference between anything. (Except "Mean Power" between the two erg setups, which you'd expect as there's less loss to unmeasured inertial body accelerations.)

[nickfishfi...@gmail.com]

Yes, it would seem that sliders may be marginally faster, but the difference is not particularly great maybe on the order of 1s / 500m over 2k.

This backs up my own experience. I did a couple of 10 stroke max tests on static vs sliders, at R20 R30 R40, and got the following results:

Rating: Static, Sliders
R20: 390w, 390w
R30: 560w, 580w
R40: 690w, 780w

On sliders the power was roughly linear with rating but static diverged over R30, presumably as the inertial losses increased. That being said, I wonder how many people are strength limited on a 2k, rather than cardiovascularly limited, so extra rating may not be of benefit. Maybe lwt's?

[Daniel Spring]

Interesting that the consensus seems to be that there is little difference between Dynamic and Sliders. I'm still left fairly speechless by Stan Louloudis's 14:51 5K.....it's a time that beggars belief.

[thomas....@googlemail.com]

> it's disappointing that the Emerson Franchini paper quoted above does
> not make a comparison with such as Rowperfect, with its far better
> rower:machine mass ratio than the C-II on slides.

As a note on this I noticed recently that the RP3 is a little heavier than the original - 17kg vs 14kg

http://www.rowperfect.co.uk/rowperfect/rowperfect-specifications/

Not sure that really changes the dynamics of it all that much however

[thomas....@googlemail.com]

If you look at valery's message I think it suggests that Dynamic has the potential for the best score, then sliders then static, however I suspect there is an amount of individuality around this since I have seen first hand some people really struggle to get anywhere near their static score on a dynamic, and then other people have done significantly better on a dynamic than the static!

In general I would say its impossible to know which is the more impressive score if comparing different machines, but for certain C2 should be issuing WR's per machine rather than bundling the static and slider together as they appear to have done (although this may have been for publicity in this case)