Increasing Outboard

[Charles Carroll]

Dear all,

I have a quick question for the RSR Brain Trust.

Can you compensate for a reduced catch angle by increasing the outboard?

Cordially,

Charles

[Charles Carroll]

I don’t know. Perhaps I should elaborate.

I had always supposed that the important reason for getting long — i.e. for
using as great a catch angle as you are capable of achieving — is that this
permits you to keep your blades in the water longer. In my simple mind if
your blades are in the water longer, you can apply power longer. And if you
can apply power longer, and hold on to your rate, then won’t you move your
shell faster?

Ok! But using a longer outboard also keeps your blades in the water longer —
leastwise this has been my experience. So if you are height challenged, as I
am, and can’t get a really great catch angle, why not just increase the
outboard?

Is there a difference in gearing between using a greater catch angle as
opposed to using a longer outboard?

Somewhere I believe that Valery Kleshnev has addressed this issue. I think,
if I am remembering correctly, he has found that a longer outboard reduces
handle velocity. I seem to remember Dr. Kleshnev's saying that handle
velocity is the telling measurement in this issue?

[thomas....@googlemail.com]

On Wednesday, March 13, 2013 6:43:23 PM UTC, Charles Carroll wrote:
> Dear all, I have a quick question for the RSR Brain Trust. Can you compensate for a reduced catch angle by increasing the outboard? Cordially, Charles

rowperfect had a article recently that may help with your question

http://www.rowperfect.co.uk/rowing-rigging-changes-you-can-do-to-change-catchfinish-angles/

Long story short, the best way of increaseing all angles (catch, finish) is to reduce inboard and span equally and adjust the stretcher to keep hands the same at finish

[James HS]

On Mar 14, 2:29 am, "Charles Carroll" <charles_carr...@comcast.net>
wrote:

Charles,

I will use my simple brain to say how I see it until someone with more
knowledge comes along to correct me :)

Longer outboard will affect the gearing. you have a worse lever (work
point further from the pin) - and for the same rate the the blade will
be travelling further, which to me means that it must also be
travelling faster (longer journey, same rate, harder lever).

I think though that a longer outboard would actually result in a
reduction in your ability to comfortably rate higher at a comfortable
pressure because the work per stroke required to hit the higher rate
is higher.

I do not have the maths brain, but I think that there is a sweet spot
for each sculler.

In my head I see it as "Which do I want" - an ability to comfortably
sit on 32, or 28 with 10% more useful angle (due to increase in
outboard).

Then another option has been proposed in the rowperfect article below
is reducing the span - i.e. in the UK this means the distance between
the two pins. This again increases the gearing in much the same way as
increasing the outboard as it moves the pin away from the outer end of
the blade, increased time in the water will again mean more work to
achieve the same rate.

Where my brain is not able to compute, is the difference - lets say in
a minute you get 10% advantage from the outboard (I have plucked this
from the air) then you are at rate 28 getting the equivalent of 2.8
strokes increase, whereas if you rate 32 then you are getting 4
strokes.

The bit that I cannot do the maths for is that the angle gain you have
is sweet spot in terms of converting work into forward movement(as I
understand it more lift and less slip) whereas the '4' strokes is a
mix of this.

Also, at a higher rate you tend to use less 'power' strokes.

I have been experimenting with this and find that I benefit more from
the ability to rate higher. I put less power per stroke and more
strokes and this tends to favour my physiology (ligthweight and short)

I have reduced my span and increased my inboard (overlap).

I have done this by using clams to bring my overlap up by 10 mm each
side (i.e. total change of overlap 20mm) which means that I can easily
change back and forth to see what it feels like.

I reduced the span first (to 158) and felt a slight increase in
gearing - rowed with this for 4 weeks and struggled at 28. Then
increased the overlap and can now sit comfortably at 30 and am
beginning to feel comfortable at 32.

having exposed my understanding of how I think this works I look
forward to a more expert analysis - as I do often find that I work
within the theory of what I understand at the time (I now draw the
boat towards me on the recovery and feel much more in control!) which
I only discovered (by being corrected on here) by exposing a miss-held
belief the last time!

James

[Charles Carroll]

Tom,

Here are the numbers that according to Valery Kleshnev’s “Rowing Speed and
Rigging Chart” are Traditional: 287/160/89.

Here are the numbers for my current rigging: 288/160/87. As you can see
these numbers are nearly identical to Dr. Kleshnev’s Traditional numbers.

Here are the numbers Dr. Kleshnev describes as “Innovative:” 269.5/152/84.5.

Dr. Kleshnev says that for someone of my height the last numbers are
“optimal for achieving the maximal boat speed in sculling.”

To rig for these optimal numbers I would have to order new riggers and oars.
Is it really worth it?

With my current riggers and oars I have played with rigging numbers quite a
lot. I have moved the pins inwards as far as they would go, shortened my
oars as short as I could make them, and decreased the inboard accordingly
(always keeping an 8cm overlap). I also have done the opposite — i.e. moved
the pins outwards as far as they could go, etc. And I have trialed lots of
combinations in between. And frankly I haven’t noticed all that much
difference.

What I am really questioning is this: is it really true that shorter rowers
can benefit from using shorter oars?

Why not just come to terms with the fact that I am short and that I am just
going to have to make the best of traditional rigging numbers?

I have had a close friend tell me to stop paying “attention to all the
pseudo-scientific tosh people tell you about load. The main thing is that
you should be comfortable with your rigging.”

And frankly the more I scull the more I find myself coming to his point of
view.

But I also concede that I have close friends who argue to the contrary …

Cordially,

Charles

[Charles Carroll]

James,

True, a longer outboard does affect the gearing.

But doesn't a greater angle at the catch also affect the gearing? Isn't this
the reason why you start out sculling short when doing racing starts -- i.e.
that you want to start the race in a lower gear and only move to a higher
gear as you pick up speed?

So why not row short with a longer outboard?

Cordially,

Charles

[James HS]

On Mar 14, 5:43 pm, "Charles Carroll" <charles_carr...@comcast.net>
wrote:

I think you row short at the start to get the rate up - like a skier
doing short spole pushes to get momentum up and then lengthening out.

And this is what I mean by a sweet spot - there is a trade off with
rate and length - typically I see scullers going off at 40+ but they
always seem to settle mid 30s and then finish 40+ - I draw from this
that there is no advantage to trying to maintain 40.

Likewise, you do not see scullers with incredibly long oars rating mid
20s with enormous push per stroke.

So somewhere there is a power per leg stroke maximum and a CV power
output endurance maximum. In my rowing club, the bigger and beefier
you are the lower the rate you seem to hold and the harder each
stroke, whereas the lighter guys tend to rate higher.

They may have just fallen into the trap that this is what they are
told is the optimum!

But I think that your rigging should probably be set to assist you in
finding your sweet spot in this equation. My opinion is that it is
probably better to err on the side of rate (cleanly well maintained
rate).

So IHMO rowing "short" is only ever employed at a start to overcome
inertia and artifically get the rate up.

There are lots of discussion on C2 websites that actually rowing short
can assist in the breaking of world records on the erg and
observations of the really fast guys sometimes bear this out! (they
sacrifice length for rate).

James

[Charles Carroll]

James,

Your reply deserves more attention than I giving it. But I am short for
time, so I thought you might not think too poorly of me if I just give you
the below link, which I hope you will find interesting.

http://www.biorow.com/RBN_en_2009_files/2009RowBiomNews01.pdf


There are many reasons for rowing short. Foir example, Ellen Braithwaite
described to me one of the times she raced the Catalina Crossing.

Ellen was in a double with a friend and they had very carefully determined
how much effort they could sustain over the period of time they would have
to race. For a crude measurement of this effort they used a SpeedCoach with
an impeller to get their through-the-water splits. When the water would
became rough and their splits got worse, they shortened up and raised the
rates. Then, as they sculled into calmer water, they dropped the rates and
got longer.


By the way, this helped me to understand the reasons why through-the-water
speed is so useful. In Ellen's case over-the-land speed -- i.e. GPS -- would
have been useless.

Cordially,

Charles

[johnf...@gmail.com]

On Thursday, March 14, 2013 1:37:36 PM UTC-4, Charles Carroll wrote:
> Here are the numbers that according to Valery Kleshnev’s “Rowing Speed and
> Rigging Chart” are Traditional: 287/160/89.
>
> Here are the numbers for my current rigging: 288/160/87. As you can see
> these numbers are nearly identical to Dr. Kleshnev’s Traditional numbers.
>

They're not "nearly identical". Your shorter inboard decreases your leverage and your greater length does the same. In terms of leverage, your setup would be equivalent to 294.6/160/89. And your shorter inboard will decrease your arc versus his Traditional setup.

[Charles Carroll]

>> Here are the numbers that according to Valery Kleshnev’s “Rowing Speed
>> and
>> Rigging Chart” are Traditional: 287/160/89.
>>
>> Here are the numbers for my current rigging: 288/160/87. As you can see
>> these numbers are nearly identical to Dr. Kleshnev’s Traditional numbers.
>>
>They're not "nearly identical". Your shorter inboard
> decreases your leverage and your greater length
> does the same. In terms of leverage, your
> setup would be equivalent to 294.6/160/89.
> And your shorter inboard will decrease your arc
> versus his Traditional setup.

John,

Obviously I am missing something. You write: “in terms of leverage.” How are
you arriving at a measurement for leverage?

I used a very simple formula for Gearing Ratio. I copied it from Dr.
Kleshnev.

My sculls are Croker Oars -- S2 Soft Superlights with Slick blade, 285
+/-3cm length, zero degree pitch, asymmetric sleeve, standard inboard,
carbon adjustable 35mm Ø handle with blue grips.

My Rigging Traditional Innovative
Spread cm 160 160 152
Oar Length cm 288 287 269.5
Inboard cm 88 89 84.5
Outboard cm 200 198 185
Overlap cm 22 20 20
Blade Length cm 43.5 43.5 43.5
Gearing Ratio 2.098 2.050 2.003

Gearing ratio was derived using inboard Inb and outboard Out in the
equation:

Kleshnev’s Formula: G = (Out - SL/2 - SW/2) / (Inb - Hnd/2 + SW/2)

Hnd = handle width (12cm in sculls) = 12cm/2 = 6cm
SW = swivel width = (i.e. thickness, 4cm) = 4cm/2 = 2cm
SL = spoon length = 43.5cm = 43.5cm/2 = 21.75cm
Range = 1.970 - 2.068, Average = 2.004)
(see RBN November 2006)
Overlap for Spread/2 + 8cm = 8cm *2 + 2*SW/2

I must be missing something. By Leverage do you mean Gearing ?Ratios? Are
the Gearing Ratios that far apart? I don’t understand how you conclude that
“In terms of leverage, your setup would be equivalent to 294.6/160/89.”

Cordially,

Charles

[James HS]

On Mar 14, 6:30 pm, "Charles Carroll" <charles_carr...@comcast.net>
wrote:

Charles

You are quite right - I should not have limited the rowing short to
starts - I often do the sculler's head on the Tideway which has a real
mix of conditions with every turn of the river and twist of the wind.

Water often gets extremely choppy and the standard 'tactic' I was
taught was to hunker down. (weightlift). 2 years ago a much more
experienced sculler than me told me that I should do the opposite - he
said 'brighten it up, keep it sharp and short through those sections.
Which I did, and it kept my splits constant.

Indeed if I am erging and find myself flagging I will often up the
rate from 30 to 32 to 34 to get a relief from the pressure on my legs
and then drop back down (if that is where I am comfortable) to finish
the piece - though I have to say I am trying to sit more comfortably
at the higher rates.

Good to know I am not the only one that likes impeller data - I use an
XL gold and post analyse my race data to see if an increase in rate
brought an increase in speed. There is a trade off where rate and
technique cross over - I rate higher but am just producing froth. The
more I practice the higher this rate becomes - and the more i build
rate work into my warm up routines the better it becomes - especially
as I race in a MX2X most of the season.

I am playing with the reduced spread to improve my catch length (I am
not the most supple of people) and so far 158 seems to suit me -
though the lack of flat water over the last few months means that this
is not as scientific as I would have liked!

James

[James HS]

On Mar 14, 6:30 pm, "Charles Carroll" <charles_carr...@comcast.net>
wrote:

Stupidly I did not say the one thinking I meant to - which is that I
use a start procedure of 1/2, 1/2, 3/4, 3/4, lengthen over 5 - which
miraculously is exactly what the model proscribes :)

This came about for a lot of reasons, a) it is memorable b) the first
2 strokes are carried out calmly more or less square blade to get the
boat moving, the 3/4 lengthen catches up with the speed of the boat
and by stroke 10 we are into our full length - 5 strokes later we call
'stride' to drop the rate to whatever we have agreed for the race
conditions and settle down to see where our opposition is and what we
should do.

James

[johnf...@gmail.com]

Your original post said your inboard was 87cm, in the table above you posted 88cm??

As a crude rule of thumb, changing the inboard 1 cm has roughly the same effect as changing the outboard 2cm, because as you saw with the calculations the outboard is roughly twice the inboard.

Your setup has two changes vs the Traditional, both of which would decrease your leverage:
- inboard 2 (or 1?) cm less
- outboard 3 (or 2? cm less)
(of course not factoring in swivel width and oar blade center of effort)

The ratio calculations are interesting because they show what a narrow range we are rigging within: "innovative" and "traditional" rations are only about 2% apart. Which also suggests that ratio may not be the best way to emphasize the differences?

It's also interesting that your rigging is about as far from "Traditional" as "Innovative" is, only in the opposite direction.

[Charles Carroll]

>Your original post said your inboard was 87cm,
>in the table above you posted 88cm??

John,

My mistake! I was looking at my notes, only I was looking at the wrong day.
The day before I had a lesson with Gordon Hamilton. In an attempt to get
just a little longer at the finish Gordon had suggested decreasing the
inboard by 1 cm. Thus the 87 cm instead of the 88. I went out the next day,
didn�t like the new rigging, and immediately reset it to 288/160/88.

Valery Kleshnev�s Traditional rigging is 287/160/89. This uses a 9 cm
overlap, which results in an 18 cm handle overlap or a total overlap of 22
cm when the swivel width is added. A total overlap of 22 cm is just too
large for me. It does not allow me to spread the oar handles far enough
apart, so it spoils my finish.

I think your point about the ratio calculations is spot on. They do indeed
show what a narrow range we are rigging within. I also don�t know how useful
these ratios are.

It seems to me that it is very easy to �change gears� in sculling. All you
have to do is change the length of your slide. Shorten up and don�t you
scull in a lower gear? Get longer and don�t you scull in a higher gear? Isn�t
it just that simple?

Notice I did not bother to mention shell velocity. Doesn�t an increase in
velocity also change the gearing?

And I have found, too, that it is also easy to change the leverage � as easy
as lowering or raising your grip on the oar handles. Take Frank Cunningham�s
suggestion that he proper way to grip is oar handle is with the forefingers
resting �on the radiused end of the handle and the second joint of the
second finger � approximately on top of it.� Doesn�t this maximize the
leverage?

Now move your grip down the oar handle so that the second joint of the
second finger is 2 cm from the radiused end of the handle. Doesn�t this
reduce your leverage and while permitting you to spread the handles just a
bit further apart at the catch?

Years back I took lessons with Christian Dahlke. Christian likes to coach
from a Double. In every lesson we did a drill where we moved our hands off
the grips and down the sculls maybe 20 or more centimeters. It really makes
a gearing change obvious.

But it is fun to play with this stuff, isn�t it? It is amazing how for some
of us rigging takes on almost religious connotations �

Cordially,

Charles

[Charles Carroll]

> I am playing with the reduced spread to improve my catch length (I am
> not the most supple of people) and so far 158 seems to suit me -
> though the lack of flat water over the last few months means that this
> is not as scientific as I would have liked!

James,

As I believe that I may have mentioned I have tried everything I could think
of to increase the time my blades are in the water drive.

1) I have moved the stretcher sternwards.
2) I have decreased the spread as far as my riggers allow.
3) I have decreased the inboard.

As a result I have improved the catch angle, frontloaded the drive, and
succeeded in prolonging the time the blades are in the water during the
drive.

I, however, am not especially happy with these results. Instead of helping
me go faster, they seem to slow me down.

Why?

Valery Kleshnev in the September 2011 RBN writes: “Changing oar length in
quite large scale doesn’t affect significantly forces, power and boat
speed … Shorter oars and lighter gearing allow faster drive and, hence,
higher stroke rate, but decrease blade efficiency.”

And then Dr. Kleshnev adds: “An optimal gearing is a balance between rower’s
and blade efficiencies and depends on rower’s dimensions and boat speed.”

It is this latter conclusion that really interests me — specifically Dr.
Kleshnev’s conclusion about blade efficiency.

I have always thought of blade efficiency in terms of how much energy is
wasted shoveling water as opposed to moving the shell. Efficient blades
move boats, inefficient blades shovel water. In other words, the more
efficient the bladework, the more useful the power produced.

But now I have reservations about this idea. It strikes me that it is
possibly too simple.

Remember Kleshnev? If shorter oars and lighter gearing allow a faster drive
and higher stroke rate, but decrease blade efficiency, then won’t longer
oars and heavier gearing slow the drive and lower the stroke rate, but
increase blade efficiency?

I have had just that experience. I had a very efficient blade, but I was
severely over-geared. As a result my handle velocity slowed considerably.
Although I prolonged the time I was able to keep my blades in the water
during the drive, I lost whatever advantage this might have given me because
it took me so long to move my oar handles from catch to finish.

So there is a balance. I am not quite sure I know what it is, but I know it
is there.

Cordially,

Charles

[Charles Carroll]

A brief elaboration, if I may …

Carl’s Law states that useful power cannot be replaced with harder work.

I had always defined useful power as a product of blade efficiency. But it
isn’t, is it?

Rather isn’t useful power what results when all the variables that create a
rowing stroke are brought into balance?

[Carl]

Not sure about 'Carl's law'...

Anyway, we must avoid mixing efficiency & effectiveness.

We want to use the oar-blade in its most _efficient_ manner, i.e. in
that way in which it throws away the least proportion of our effort in
showy but useless turbulence, etc. Liken that to reducing wheel-spin,
tyre wear, smoke & tyre heating in a race car

And we need to use the body in its most _effective_ way, which means
being able to apply those loads over that distance at that frequency
which enables us to maximise our power output. This is like the gearing
of a bike (or car) - a device to enable the body to work at its optimum
rate. It is not necessarily inefficient (it doesn't necessarily waste
power) if we select the wrong gearing but we won't go as fast. That's
principally because the human body, like many engines, has a sweet-spot
combination of speed of action with muscular loading at which it can
develop the greatest output power.

You can see this when riding a bike uphill. If you progressively harden
the gearing, the point will be reached at which the force you can apply
to the pedals is no longer sufficient to enable you to move the bike
forward. At that point your power output will be exactly zero, despite
the huge force you're applying.

And at the other end of the scale you can set the gearing so soft that
you must move your legs so fast that your muscles can't act fast enough
to apply much useful load, so the useful power output again diminishes.

Another analogy is in the lifting of weights: there'll be a weight on
the bar which you can loft above your head only once. That weight might
be only 20% greater than the weight you can lift 50x. So in the first
case you do a maximum of 1 x 120 arbitrary units of work & can't even
lift that load a second time while in the second you do 50 x 100 of the
same work units, & could probably keep going (maybe slower) thereafter.
So we need to pick our gearing with care to be able to maximise our
work rate over the distance we plan to row: gear too severely & we'll
get there but slowly, gear too lightly & we won't be able to move our
limbs & body fast enough to do the necessary work at the resulting
reduced loadings, but pick somewhere in between those extremes & there
will lie the sweet spot which allows us to hit our record time for that
course.

Some simple rules & equations:
1. Work rate (power) = force x speed of action
2. We have a physical limit to the maximum force we can apply, at which
loading there can be no movement
3. We have a physical limit to the speed at which we can move our hands
along the boat, at which there can be no force available to do useful work

So if we want to maximise the product of that simple equation, we are
not maximising force with no motion (zero speed) & not maximising speed
either (zero force), since both of them result in zero work but seeking
that happy medium.

That's why a too severe gearing may let you pull very hard but reduces
boat speed & a too light gearing prevents you also from maximising your
speed. Beware the simple assumption, often applied by rowers to the
tightening of rigger bolts, that if some is good then more must
automatically be better. Compromise is the name of the smartest game in
town. But that's about effectiveness, not efficiency.

HTH?
Carl

--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing Low-drag Riggers/Advanced Accessories
Write: Harris Boatyard, Laleham Reach, Chertsey KT16 8RP, UK
Find: tinyurl.com/2tqujf
Email: ca...@carldouglas.co.uk Tel: +44(0)1932-570946 Fax: -563682
URLs: carldouglas.co.uk & now on Facebook @ CarlDouglasRacingShells

[James HS]

On Wednesday, March 13, 2013 6:43:23 PM UTC, Charles Carroll wrote:

Carl has made this very succinct.

I personally am aiming for a higher rate as i do not think that my personal sweet spot in in the ability to apply leg force, but rather in the ability to apply the slightly lower leg force at a higher rate and speed.

I have done two slightly conflicting changes - standardised by span on 158 - because when I measured it it was 159 and assymetrical, and on the advice of my coach I have increased my overlap by popping in some clams - so 10mm either side.

However, to make use of these changes I need to up my typical rating, and I am concentrating specific exercises on this - so while i still do my long slow erg sessions (60R20) I am concentrating much more on Interval sessions (500 r 1:30) and 5K at 32+ - On he water I am trying to repeat these sequences Warm ups @R20 with bursts in a pyramid 24/26/28/30 and then 'pieces' of 1K in pyramids 26/28/30/32 (500K active rest between)

On the tideway this can be a bit 'tricky' but I want to get to a position where higher rating is more of the norm.

I find the higher rating also brings me more stability in the boat - a better 'rythm' as opposed to "individual strokes" and also helps me get used to steering at this higher activity rate!

So personally I have decided to "commit to the rate" and see how it goes - may even head up to 34 if my 'system' allows it!

Whereas I used to be in the long blade push hard camp - so this is a bit of a change :)

James

[A. Dumas]

This weekend I increased the outboard of a sculler I coach, actually
just shifted the buttons:

Spoons : C2 Big Blade 44 x 21,5
Sculls : 288,0 (no change)
Span : 160,0 -> 159,0 (action)
Inboard : 89,0 -> 88,0 (action)
Outboard : 199,0 -> 200,0 (consequence)
Overlap : 18,0 -> 17,0 (consequence)

Sculler: male, senior, 188 cm, wing span +/- 195 cm, 86 kg, 6:04 erg. He
is stronger than last year so smaller lever ratio warranted, also wanted
to increase his arc a little and give him a little more room at the
finish. Target rate 32-34 on 2k in single scull. I know it'll drop to 30
on bad days, rigging change not so good for that, we'll have to see how
increased strength/power will handle that. Then again, it'll take a good
day to reach international finals anyway.

Sorry, just a random outboard anecdote.

[Charles Carroll]

> avoid mixing efficiency & effectiveness.

Carl,

Is there a serviceable distinction to be made between efficiency and
effectiveness? If there is, I confess that I am too dense to see it.

Instead what I see is the meaningless repetition of two words that signify
the same thing. In other words, it seems to me that the statement is
tautological.

I cannot see why the most efficient system wouldn’t be the most effective.
And vice versa!

I concede that it is always possible to break down a system into its
component parts, and then, without regard as to how these components fit
together, maximize the efficiency of each component, only to find that all
the components, when reassembled, produce a highly inefficient system.

Maybe a good example of this is trying to build a shell with the most
efficient hull geometry. Am I wrong to think that this would be a hull
geometry with the least resistance? But build a shell with such a geometry,
put it back into the system, and what do you get? An unrowable shell as I
understand it! So we have an efficient component in an inefficient system.
Or an ineffective system? Or an ineffective component in and inefficient
system. Almost every way it seems to work.

What I am suggesting is that trying to make a distinction between efficient
and effective is just playing with words, unless of course you want to
reaffirm Aristotle’s distinction between an efficient cause and a final
cause. In that case, however, haven’t you changed the definition of
efficient?

The reason I am carrying on about this is that I cannot make heads or tails
of Dr. Kleshnev’s Figure 1 in the October 2011 issue of the Rowing
Biomechanics Newsletter.

http://www.biorow.com/RBN_en_2011_files/2011RowBiomNews10.pdf

I await enlightenment …

Cordially,

Charles

[Charles Carroll]

James,

I changed my gearing this morning from 288/160/88 to 285/160/88. This took 3
cm off the outboard.

The two things I am looking for in the revised rigging are

• Lighter gearing
• Easier sculling in rough water

INITIAL IMPRESSIONS OF THE RIGGING CHANGES

I must say that for the brief time I was on the water this morning I
scarcely noticed any difference in the gearing. I was able to establish
relatively quickly the “essential tensile connection between the mass of
water behind the backs of the blades and the backs of the blades
them-selves.” And once this tensile connection was established, the blades
held on to the water well.

Also my stroke rate did not seem any higher than usual. But I concede that I
didn’t try to scull at a high rate.

So there is very little I can conclude. My sculling felt pretty much as
usual. I moved the shell, the shell felt stable, and I felt confident.

The only thing worthy of note was the display on the NK SpeedCoach GPS.
However routine my sculling felt to me, that display insisted I was sculling
faster than I usually scull. It was the bright spot in my day.

And one other thing! I came off the water this morning thinking that I had
sculled as well, if not better, than I can recall ever having sculled.

It is difficult not to conclude that as much as I liked the old rigging the
numbers they were all wrong. I clearly have been over-geared. A 200 cm
outboard with my oars is just too much gearing for me. True, with a 200 cm
outboard I did see an increase in the duration my blades were in the water
during the drive. At the same time, however, my handle velocity decreased
significantly. So any advantage gained by increasing the time my blades were
in the water was negated by the loss of handle velocity. To put it simply, a
200 cm outboard forced me to work harder to go slower. Not a good outcome!

Cordially,

Charles

[James HS]

Charles,

That sounds like a good result.

I think that the faster rate takes a while to bed in and is something worth practicing with.

I would definitely recommend pyramids - pick a calm day (:)) and do a warm up (I normally recommend a minimum of 4K with 10 stroke bursts aimed at rate not pace (i.e. little work)

Then get ready for some intervals - whatever distance you are happy with. early in the season I do 300 metres on, 300 metres 'light' and start 24/26/28/30 - later in the season I am able to go up to 500m and 26/28/30/32

I am sad and record these using the XL2 gold and impeller - I then do not compare 'absolutes' as the Tideway is rarely the same in terms of conditions, but I am looking for an increase in pace from each rate rise, and I am trying to feel when the wheels fall off.

The more I do this the higher the rate before the wheels fall off, and the better the pace gain!

But it would be good to then compare the rigging differences - as i personally like to quantify the change as well as sensing that it 'feels' good!

James

[s...@ku.edu]

Charles,

At the catch/entry, where is your seat relative to the line of work?

[Carl]

On 19/03/2013 17:27, Charles Carroll wrote:
>> avoid mixing efficiency & effectiveness.
>
> Carl,
>
> Is there a serviceable distinction to be made between efficiency and
> effectiveness? If there is, I confess that I am too dense to see it.
>
> Instead what I see is the meaningless repetition of two words that
> signify the same thing. In other words, it seems to me that the
> statement is tautological.
>
> I cannot see why the most efficient system wouldn’t be the most
> effective. And vice versa!

Charles - your namesake, Lewis Carroll, had quite a way with words.
IIRC, he had Humpty Dumpty tell Alice that when he used a word it meant
exactly what he wanted it to mean.

Efficiency is the fractional or percentage part of the work you generate
which does not go to waste but does the job you require of it.

Effectiveness describes how well a given machine - in this case you -
can do work. So, if you are hunched up or tied down in a way which
restricts your own movement you will be less effective as a motor, even
though the work you do might be converted very efficiently into boat
propulsion. Similarly, if you gearing is too severe you won't (as you
have today reported) be able to move the boat as fast - because, pull as
you might, you'll be unable to create that combination of speed of
action & force of pull that allows you to maximise your power output
according to the equation: Power = Force (applied) x Speed (of action)

Do not get tied down in a technical argument by what the words being
used might mean in, say a literary or poetic setting. Science uses
words in very specific ways and their meanings must be accepted as such
in that particular context. I believe in Quantum Theory that terms such
as colour, charm & spin are used and perfectly understood in ways that
are meaningless to the rest of us. Similarly we get inane vapourings
against the doings of Charles Darwin from folk who fail to understand
that the word 'Theory' in a scientific context does not mean 'Guesswork'
but indicates a concept which has held firm against all the most
rigorous of scientific tests.

Cheers -

[A. Dumas]

Any comments on the anecdotal data? Does it seem heavy, light or typical?

[Charles Carroll]

> Any comments on the anecdotal data?
> Does it seem heavy, light or typical?

Ok, let me see if I understand it. You have changed sculler from 288/160/89
to 288/160/88. So you have added a centimeter to the outboard and reduced
the inboard by a centimeter.

This makes the gearing heavier. But the real question is whether the new
made heaviness is significantly much heavier? Does it signify?

Let’s start with Valery Kleshnev. “Facts. Do you know that changing oar
length a few cm does not dramatically affect rowing biomechanics?” (RBN
September 2011)

My recent experiments with my own gearing confirm Dr. Kleshnev’s statement.
And I reduced my outboard by not 1cm but by 3cm! I just couldn’t feel any
difference. The only way I could tell the effectiveness of this change was
by the reading on the SpeedCoach. This reading told me that for the same
“perceived effort” I was sculling at a faster pace.

Your sculler may perceive the change because you changed his inboard, too.
Or he may just be more sensitive to change than I am.

What I am trying to say is that judging by my experience and Dr. Kleshnev
statement, the only way you are going to ascertain the effect of the changes
you have made is by objective measurement. So try to get your sculler to
scull pieces at different rates using some kind of measuring device; and
then compare the data to the data you have from his former rigging. But don’t
forget that you have said that he is also stronger and has improved his
technique.

Your sculler is 185 cm tall. That is not terribly tall, but he is not small
either. He should be able to get a pretty good catch angle. Have you
measured it?

If you can rig him for a decent catch angle while keeping his finish, and
keep his gearing light enough, and if his physiology and motivation are
there, I would think that he should have a pretty good on-water 2k, that is,
if his erg score is any indication.

I have friends who insist that if you really want to make serious rigging
changes, you’ll have to purchase new riggers and shorter oars. They
absolutely insist on this. But I have questions.

I’ll end by adding one other thought. Kleshnev states that there is solid
evidence that shorter rowers can benefit from shorter oars. While this may
be true, you should also remember something else Dr. Kleshnev has said —
namely, that traditional rigging with traditional numbers has designed for
someone just about the size of your sculler.

Cordially,

Charles

[A. Dumas]

Charles Carroll wrote:
>> Any comments on the anecdotal data?
>> Does it seem heavy, light or typical?
>

> This makes the gearing heavier. But the real question is whether the
> new made heaviness is significantly much heavier? Does it signify?

I know it makes for a hardly perceptable difference. And I also know
it's a fairly typical, to light, gearing for scullers of his standing
around here. I was just wondering how the absolute numbers, not the
change, would be received by an international audience.

> If you can rig him for a decent catch angle while keeping his finish,
> and keep his gearing light enough, and if his physiology and motivation
> are there, I would think that he should have a pretty good on-water 2k,
> that is, if his erg score is any indication.

He's fairly decent, going by last year's confrontations I'd say Olympic
D-final level, maybe towards C.

> I’ll end by adding one other thought. Kleshnev states that there is
> solid evidence that shorter rowers can benefit from shorter oars. While
> this may be true, you should also remember something else Dr. Kleshnev
> has said — namely, that traditional rigging with traditional numbers has
> designed for someone just about the size of your sculler.

Ah yes of course, nice "gotcha." We weren't prepared to make radical
changes anyway; it would be to much of a physiological challenge with
the season almost starting. Thanks for your response.

[A. Dumas]

A. Dumas wrote:
> Ah yes of course, nice "gotcha." We weren't prepared to make radical
> changes anyway; it would be to much of a physiological challenge with
> the season almost starting. Thanks for your response.

*too* much.

[Charles Carroll]

> Ah yes of course, nice "gotcha."

Fred,

Actually, that was a serious question. There was no gotcha intended. I never
play “gotcha.” I find that it is too easy for it to degenerate into a
particularly mean and vicious entertainment.

For some time now, since Valery Kleshnev proposed that shorter rowers might
benefit from shorter oars, I have wondered why this also wouldn’t hold true
for taller rowers. If shorter showers can benefit from shorter oars, why
wouldn’t taller rowers also benefit from shorter oars?

I have an idea. But I am more interested in what more knowledgeable people
think.

Cordially,

Charles

[Carl]

A racing-shell rowing stroke (as opposed to that for a much slower
whaler or gig) needs to cover a certain arc since the ends of that arc
achieve a higher conversion of the work you put in to actual propulsive
(useful) work done by the blade - i.e. a higher propulsive efficiency -
while the middle of the stroke has a higher proportion of wasted work
that goes to make useless puddles & thus has a lower propulsive
efficiency. That's down to fluid dynamics.

If you take too long a stroke arc for the speed of the boat, then the
gearing at the extremes of the arc becomes too severe for the body to do
much work (you are less effective as a motor) because the speed of
action at the extreme end is too much reduced. A faster boat speed
warrants a longer arc, but at lower speeds the absolute physical limit
on how hard you can pull means that Speed of action x Force applied is
much reduced. no point in having a very high efficiency in a part of
the stroke if the power you are able to apply there is too far reduced
(i.e. your effectiveness there is too far reduced).

[A. Dumas]

Charles Carroll wrote:
>> Ah yes of course, nice "gotcha."
>
> Fred,
>
> Actually, that was a serious question. There was no gotcha intended. I
> never play “gotcha.” I find that it is too easy for it to degenerate
> into a particularly mean and vicious entertainment.

I didn't see a question there, only observations of two things Kleshnev
said. By gotcha I meant "Good reminder" or "Ah yes of course" or indeed:
"Got it."

Not sure why you call me Fred (not that I mind).