26 Nov 2003 20:58:33
Tony Curran
More Layback at the finish...

Is this good or bad.

Mr. Spracklen has been recorded as stating 75% of the energy put in to a
stroke comes from the legs, 12.5% from the arms and 12.5% from the back -
probably from a RCA magazine from the early 90's when he was coaching the 92
crew winners in Spain.

So to over accentuate the layback at the finish one is trying to get that
little extra at the end of the stroke to take advantage of a bit more length
and the greater efficiency that hydrodynamic lift avails as the angle of
attach increases. But does this benefit have a diminishing return?

To lay back that little bit further, it takes time. It takes even more time
to bring the torso back forward again. Thus it limits the rate at which one
can row at.

The Danish lwt 4- is a good example of how lifting the rate to 40+ strokes
per minute in the last 500m allowed them to row through many crews,
including the Canadian 4- at Atlanta. If they had a long layback as
demonstrated by the Canadians at the trials in BC then they wouldn't have
been able to increase the rate and apply power with the bigger leg muscles
for more strokes.

So the argument is that the extra layback is NOT beneficial if it prevents
the crew from raising its rate. A more traditional layback (15 degrees???)
would allow a higher rate to be achieved where the stronger leg muscles can
be used more often.

Yes. No. Interested in your thoughts...

Tony
Ottawa RC




27 Nov 2003 11:06:31
Nick Suess
Re: More Layback at the finish...


Tony Curran <tony.curran@sympatico.ca > wrote in message
news:fOcxb.15145$dt2.1136505@news20.bellglobal.com...
> Is this good or bad.
>
> Mr. Spracklen has been recorded as stating 75% of the energy put in to a
> stroke comes from the legs, 12.5% from the arms and 12.5% from the back -
> probably from a RCA magazine from the early 90's when he was coaching the
92
> crew winners in Spain.
>
> So to over accentuate the layback at the finish one is trying to get that
> little extra at the end of the stroke to take advantage of a bit more
length
> and the greater efficiency that hydrodynamic lift avails as the angle of
> attach increases. But does this benefit have a diminishing return?
>
> To lay back that little bit further, it takes time. It takes even more
time
> to bring the torso back forward again. Thus it limits the rate at which
one
> can row at.
>
> The Danish lwt 4- is a good example of how lifting the rate to 40+ strokes
> per minute in the last 500m allowed them to row through many crews,
> including the Canadian 4- at Atlanta. If they had a long layback as
> demonstrated by the Canadians at the trials in BC then they wouldn't have
> been able to increase the rate and apply power with the bigger leg muscles
> for more strokes.
>
> So the argument is that the extra layback is NOT beneficial if it prevents
> the crew from raising its rate. A more traditional layback (15 degrees???)
> would allow a higher rate to be achieved where the stronger leg muscles
can
> be used more often.
>
> Yes. No. Interested in your thoughts...
>
> Tony
> Ottawa RC

I reckon those French guys at Sydney were the best example of an amazingly
high rating achieving an astonishing result. But the other side of the coin
is that doing 35 good strokes in a minute is likely to be more effective
than 45 crap strokes. I'd estimate that a big lay back like that adds
something like 7% to overall stroke length. So is it an effective 7%? Is it
worthwhile because of hydrodynamic lift in that part of the blade arc?

I'm not especially persuaded by the discussion on energy considerations you
point out. What percentage of that total energy is going to create a big
swirling puddle? The point being that reducing wasted energy will have more
effect on boat speed than trying to squeeze out the last ounce of energy
input. And in a big lay back, how much energy is expended against gravity in
repeatedly raising and lowering the upper body mass of the rower? It's
almost like adding the work of 40 push-ups per minute to that of propelling
the boat.




27 Nov 2003 04:29:18
Dave Henderson
Re: More Layback at the finish...

"Tony Curran" <tony.curran@sympatico.ca > wrote in message news:<fOcxb.15145$dt2.1136505@news20.bellglobal.com>...

> Is this good or bad.
>
> Yes. No. Interested in your thoughts...
>
> Tony
> Ottawa RC

What the great man himself *used* to think
(extracted from his treatise on technique, to be found all over the
Web)

The most efficient part of the stroke is when the blade is passing at
90 degrees to the boat. Only when it is at this angle is its force
propelling the boat wholly in the correct direction. In theory an
efficient length of the stroke is from 45 degrees at the catch to 135
degrees at the finish. In practice the body prevents the oar from
reaching more than 125 degrees. To achieve 45 degrees at the catch,
the reach must extend beyond this angle. A longer finish can be drawn
in a sculling boat but it is inefficient to draw more than 130
degrees.

The Finish:
Body upright advantages less weight on the bow, less use of
stomach muscles
Disadvantages - reduced leverage of trunk, weaker finish

Long swing advantages longer and stronger finish
Disadvantages hands draw higher, pressure on bow, more value in
slower boats


Dave H
Royal S.N. de Bruxelles


27 Nov 2003 05:46:22
David
Re: More Layback at the finish...

"Nick Suess" <nick@scull.com.au > wrote in message news:<3fc56ae5$0$1756$5a62ac22@freenews.iinet.net.au>...
> Tony Curran <tony.curran@sympatico.ca> wrote in message
> news:fOcxb.15145$dt2.1136505@news20.bellglobal.com...
> > Is this good or bad.
> >
> > Mr. Spracklen has been recorded as stating 75% of the energy put in to a
> > stroke comes from the legs, 12.5% from the arms and 12.5% from the back -
> > probably from a RCA magazine from the early 90's when he was coaching the
> 92
> > crew winners in Spain.
> >
> > So to over accentuate the layback at the finish one is trying to get that
> > little extra at the end of the stroke to take advantage of a bit more
> length
> > and the greater efficiency that hydrodynamic lift avails as the angle of
> > attach increases. But does this benefit have a diminishing return?
> >
> > To lay back that little bit further, it takes time. It takes even more
> time
> > to bring the torso back forward again. Thus it limits the rate at which
> one
> > can row at.
> >
> > The Danish lwt 4- is a good example of how lifting the rate to 40+ strokes
> > per minute in the last 500m allowed them to row through many crews,
> > including the Canadian 4- at Atlanta. If they had a long layback as
> > demonstrated by the Canadians at the trials in BC then they wouldn't have
> > been able to increase the rate and apply power with the bigger leg muscles
> > for more strokes.
> >
> > So the argument is that the extra layback is NOT beneficial if it prevents
> > the crew from raising its rate. A more traditional layback (15 degrees???)
> > would allow a higher rate to be achieved where the stronger leg muscles
> can
> > be used more often.
> >
> > Yes. No. Interested in your thoughts...
> >
> > Tony
> > Ottawa RC
>
> I reckon those French guys at Sydney were the best example of an amazingly
> high rating achieving an astonishing result. But the other side of the coin
> is that doing 35 good strokes in a minute is likely to be more effective
> than 45 crap strokes. I'd estimate that a big lay back like that adds
> something like 7% to overall stroke length. So is it an effective 7%? Is it
> worthwhile because of hydrodynamic lift in that part of the blade arc?
>
> I'm not especially persuaded by the discussion on energy considerations you
> point out. What percentage of that total energy is going to create a big
> swirling puddle? The point being that reducing wasted energy will have more
> effect on boat speed than trying to squeeze out the last ounce of energy
> input. And in a big lay back, how much energy is expended against gravity in
> repeatedly raising and lowering the upper body mass of the rower? It's
> almost like adding the work of 40 push-ups per minute to that of propelling
> the boat.


The body swing on it's own provides very little useful propulsion. It
has to be worked in effectively with the leg drive - the idea of
connect, hang and push is used by many coaches to relay this concept.
It is the posture rather than the body swing that is key. Effective
posture = effective connection. As soon as you loose that posture
through slouching or lying back then the connection is lost between
the legs and water and you're doing nothing for moving the boat - if
anything the blade is slowing down and thus acts as a brake! Basically
support your torso, sit tall and pivot from the hips; don't slouch and
make sure you're connected from the catch to the finish and you'll be
right. The rate can take care of itself from there!


27 Nov 2003 15:00:18
Ewoud Dronkert
Re: More Layback at the finish...

"David" <d_avidmcneill@hotmail.com > wrote:
> support your torso, sit tall and pivot from the hips

I thought, hey I read that somewhere before, but no I phrased it slightly
differently: http://www.triton.studver.uu.nl/?p=techniekSuggestions for
clearer phrasing welcome (see my e-mail address at the bottom of the page).

E.