Anyone from RSR down here in NZ to watch the race on Sunday?
www.thegreatrace.co.nz/

Walter - are you around?

We could have a nice RSR group meet-up and gossip / beer / coffee
Rebecca Caroe

On Sep 3, 4:17 pm, "rebe...@caroe.com" <rebecca.ca...@googlemail.com>
wrote:
> Anyone from RSR down here in NZ to watch the race on Sunday?www.thegreatrace.co.nz/
>
> Walter - are you around?
>
> We could have a nice RSR group meet-up and gossip / beer / coffee
> Rebecca Caroe

Well... Rebecca contacted me on Skype. I'm helping as a range
official at the National Action Pistol Championships, at the Hamilton
Pistol Club on Saturday, and then on Sunday hanging around at the
Great Race.
Ms. Caroe will be borrowing a 1X from the Cambridge RC tomorrow, and
then (or perhaps before hand) paying a visit at the RNZ office, to see
the chaos in which I work.
Whee. Charles - you let someone else ROW your CD? Wow.
Walter

Hello Walter,

Guilty as charged.

I told Rebecca that she should consider my boat hers during the time she was
here. But she only rowed it once, last Sunday.

She went out with a group of people and told me she had a wonderful time.

But what Rebecca didn't tell me is that she and my friend, David Lay, raced
each other from the 101 Bridge to the #4 channel marker. According to my
Garmin Forerunner that is exactly 2k.

The first thing I heard Monday when I got to the Club is, "Rebecca beat me."

"What? You raced Rebecca again? She didn't tell me that."

"Yes. And she beat me," said David. "You know she only beat me because she
was rowing your boat."

"Oh come on!"

"It's true. I was rowing my 24. She had your boat."

"Rebecca really beat you?"

"Yeah!"

"I know she is a good sculler. She has a very clean technique. But I didn't
think she could beat you."

"Well, she did, and it's because she was rowing your boat. Carl's boat!"

David made it sound as though it were my fault. But we all know at whose
door we should lay the blame. Carl's door of course! It's all Carl's fault.
If only he didn't build such beautiful boats, then the people shouldn't beat
us wouldn't beat us.

The funny thing is that the boat isn't even rigged right. I had a lesson
with Gordon Hamilton Tuesday, and one of the things we did was go over the
rigging. Tomorrow I am moving the tracks about 2cm towards the stern so I
can get through the pins. Then I am going to decrease the inboard on the
oars from 86cm to 85cm. Gordon thinks these changes should give me the reach
I am missing at the entry.

Cordially,

Charles

David was being pretty generous.... he gave me a head start
and then half way down the course he tried one of his 'distract your
opposition' tricks - forcing me wide.

Stupidly, I didn't realise he was doing this as I was staying a
crucial half length in front of him and using him as a steering
guide. So I just followed him over
then he left me for dead having sculled an extra 25 meters in
wiggles.....[and he never told me exactly where the finish line was
either!!!]

I really enjoyed it.

should come back for more (racing and your CD boat!)

cheers, guys!

On 4 Sep, 01:20, "Charles Carroll" <charles_carr...@comcast.net>
wrote:
snip
>Then I am going to decrease the inboard on the
> oars from 86cm to 85cm. Gordon thinks these changes should give me the reach
> I am missing at the entry.
>
> Cordially,
>
> Charles

Wow, that's fairly small. How long are your sculls? Also, are you
going to decrease the span accordingly?

Kit

On Sep 4, 4:31 pm, boatie <rebe...@caroe.com> wrote:
> David was being pretty generous.... he gave me a head start
> and then half way down the course he tried one of his 'distract your
> opposition' tricks - forcing me wide.
>
> Stupidly, I didn't realise he was doing this as I was staying a
> crucial half length in front of him and using him as a steering
> guide.  So I just followed him over
> then he left me for dead having sculled an extra 25 meters in
> wiggles.....[and he never told me exactly where the finish line was
> either!!!]
>
> I really enjoyed it.
>
> should come back for more (racing and your CD boat!)
>
> cheers, guys!

Did you get to the Cambridge RC Thursday? Bunches of people are going
out these days - school programmes are getting started, the rain's let
up, the weather's warm again, plum blossoms are busting out all
over...
I'll be in the RNZ offices again Friday for the day - pop up for a
coffee or tea...
(eye app't at 8, though, so probably not there til 9)
Walter

On 4 Sep, 20:57, wmart...@gmail.com wrote:
> On Sep 4, 4:31 pm, boatie <rebe...@caroe.com> wrote:
>
>
>
> > David was being pretty generous.... he gave me a head start
> > and then half way down the course he tried one of his 'distract your
> > opposition' tricks - forcing me wide.
>
> > Stupidly, I didn't realise he was doing this as I was staying a
> > crucial half length in front of him and using him as a steering
> > guide.  So I just followed him over
> > then he left me for dead having sculled an extra 25 meters in
> > wiggles.....[and he never told me exactly where the finish line was
> > either!!!]
>
> > I really enjoyed it.
>
> > should come back for more (racing and your CD boat!)
>
> > cheers, guys!
>
> Did you get to the Cambridge RC Thursday? Bunches of people are going
> out these days - school programmes are getting started, the rain's let
> up, the weather's warm again, plum blossoms are busting out all
> over...
> I'll be in the RNZ offices again Friday for the day - pop up for a
> coffee or tea...
> (eye app't at 8, though, so probably not there til 9)
> Walter

And are you around on Friday or Saturday? I am playing around with
umpire/safety boats helping getting them from Karapiro to Hamilton. I
am driving the main umpire boat on Sunday so will be around. See what
I can do.

Taniwha

Kit,

Here are the changes I made in the rigging this morning.

I moved the footstretchers about 2 cm towards the stern. I also moved the
tracks about 2 cm. The seat now moves through the pins. This is a particular
embarrassment to me. In the year that I have been rowing my boat, Gordon
Hamilton is the only one who noticed that my seat was about 2 cm short of
being able to move through the pins.

I also made the following changes in my oars:

Spread cm 158
Total Oar length cm 287
Inboard cm 85
Outboard cm 202
True Outboard cm 179.6
Load 2.27

Inboard is measured from oar handle to outside collar.
Outboard is measured from inside collar to blade tip.
True Outboard is measured from inside collar to Blade Centroid (Outboard -
20.9 cm).
Load is True Outboard divided by 1/2 the Spread.

Total Oar length remained the same as I had it. So all I did was decrease
the inboard a centimeter, and increase the outboard a centimeter.

You may be wondering about True Outboard and Load. These come from Jim
Dreher and are measurements for his oars. Do they apply to Crokers? Probably
not. But it is interesting to me that I only increased the Load 0.01 from
what it was. (2.26 to 2.27)

I only had about twenty minutes of sculling after I made these changes. The
boat feels significantly improved. I think this has to do with getting
through the pins.

Cordially,

Charles

Charles Carroll wrote:
> Kit,
>
> Here are the changes I made in the rigging this morning.
>
> I moved the footstretchers about 2 cm towards the stern. I also moved
> the tracks about 2 cm. The seat now moves through the pins. This is a
> particular embarrassment to me. In the year that I have been rowing my
> boat, Gordon Hamilton is the only one who noticed that my seat was about
> 2 cm short of being able to move through the pins.
>
> I also made the following changes in my oars:
>
> Spread cm 158
> Total Oar length cm 287
> Inboard cm 85
> Outboard cm 202
> True Outboard cm 179.6
> Load 2.27
>
> Inboard is measured from oar handle to outside collar.
> Outboard is measured from inside collar to blade tip.
> True Outboard is measured from inside collar to Blade Centroid (Outboard
> - 20.9 cm).
> Load is True Outboard divided by 1/2 the Spread.
>

I'm always wary of assumptions re the relevance of the centroid of the
blade (= centre of area). Since an oar-blade passes through such a wide
range of fluid flow regimes from catch to finish, the centroid location
can have no more real meaning than the location of the tip or the root -
it's just another measurement among others of uncertain significance.

I make this seemingly nit-picking point 'cos rowers just love to have
"hard & fast" numbers to work with. Unfortunately, the value of those
numbers depends greatly on just how you use the oar:

Do you go deep or shallow? Going shallow means more slip so the
apparent centre of effort (turning point) at various points in the
stroke will move inboard. While that will make the gearing seem easier,
it really does nothing of the sort, just provides a means for throwing
away effort.

Do you load the ends of the stroke or the middle? If it is the ends,
then the centre of effort at the catch will be out towards the blade
tip, & at the finish will approach the blade root. If you load up the
middle, that'll increase slip in that stall phase, seeming to bring the
centre of effort inboard & maybe even to around the neck.

So the use of the word "true" should be avoided.

> Total Oar length remained the same as I had it. So all I did was
> decrease the inboard a centimeter, and increase the outboard a centimeter.
>
> You may be wondering about True Outboard and Load. These come from Jim
> Dreher and are measurements for his oars. Do they apply to Crokers?
> Probably not. But it is interesting to me that I only increased the
> Load 0.01 from what it was. (2.26 to 2.27)

But you changed your stroke arc, which altered the distribution of your
effort across the continually changing spectrum of fluid dynamic regimes
met by the oarblade. A trivial change in that invented parameter
tells you so little about the real changes that you've made.

The world of engineering, not least of fluid dynamics, was made more
comprehensible & manageable by the wonderful insights yielded up by the
application of relevant dimensionless groups, e.g. Reynolds number,
Froude number & Strouhal number. But it took real insight to see that
these, & not other, numbers encapsulated in dimensionless (pure number)
form certain truly significant physical relationships that are
critically descriptive of the system.

Just because someone invents another dimensionless number as a
mathematical function of certain parameters of a system does not mean it
helps you understand a system. As in this case, the chosen relationship
may look good on paper but in reality bear scant relevance to the
physical processes to which they are then applied.

>
> I only had about twenty minutes of sculling after I made these changes.
> The boat feels significantly improved. I think this has to do with
> getting through the pins.
>

Very possibly. It gives you more of your stroke in the most efficient
part of the stroke. If, & only if, you are able or naturally disposed
to make best use of that change, as seems the case here, then you stand
to benefit & go faster. But beware finding, in time, that the benefit
has faded as the subconscious decides to slide away from doing the
things which first gave you that speed improvement under the changed rig.

Cheers -
Carl

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

Charles Carroll schrieb:
> I moved the footstretchers about 2 cm towards the stern. I also moved
> the tracks about 2 cm. The seat now moves through the pins. This is a
> particular embarrassment to me. In the year that I have been rowing my
> boat, Gordon Hamilton is the only one who noticed that my seat was about
> 2 cm short of being able to move through the pins.

I don't know if this helps you, but the settings on my boat have evolved
over about 4 or 5 years. I do remember that I raced it on its first
outing at the Vechtrace with the stretcher set to factory default -
that's in the 'middle' position. Today I have it set two units from the
stern, so it moved quite a lot over time.

Carl encouraged me to share my experience with my new oars (for the
not-yet-built sectional single - don't rush!), which I ordered under the
impression of Charles' report on his new Croker oars. The new ones are
Dreissigackers (I don't like the ergonomics of Croker), with Smoothie2
blade + vortex, 'ultralight' type (not low-i), 10 cm adjustment handle
and, most importantly, soft shaft.

It probably was my holiday or the psychological boost, but my speedcoach
gave me 500m splits I've never reached before. I thought it might have
been helped by better loaded shafts which made extraction much cleaner
(less noise). Tonight I put my old blades in (same rig, but smoothie1 +
vortex, medium stiffness and heavy shaft). Ok, I had a good week's work,
but the split times where back to 'normal'.

Can anyone explain or share some more considerations when switching
between light/heavy or soft/medium stiffness? Is one able to feel the
shaft stiffness in more or less back pain?

Henning Lippke wrote:
> Charles Carroll schrieb:
>> I moved the footstretchers about 2 cm towards the stern. I also moved
>> the tracks about 2 cm. The seat now moves through the pins. This is a
>> particular embarrassment to me. In the year that I have been rowing my
>> boat, Gordon Hamilton is the only one who noticed that my seat was
>> about 2 cm short of being able to move through the pins.
>
> I don't know if this helps you, but the settings on my boat have evolved
> over about 4 or 5 years. I do remember that I raced it on its first
> outing at the Vechtrace with the stretcher set to factory default -
> that's in the 'middle' position. Today I have it set two units from the
> stern, so it moved quite a lot over time.
>
> Carl encouraged me to share my experience with my new oars (for the
> not-yet-built sectional single - don't rush!), which I ordered under the
> impression of Charles' report on his new Croker oars. The new ones are
> Dreissigackers (I don't like the ergonomics of Croker), with Smoothie2
> blade + vortex, 'ultralight' type (not low-i), 10 cm adjustment handle
> and, most importantly, soft shaft.
>
> It probably was my holiday or the psychological boost, but my speedcoach
> gave me 500m splits I've never reached before. I thought it might have
> been helped by better loaded shafts which made extraction much cleaner
> (less noise). Tonight I put my old blades in (same rig, but smoothie1 +
> vortex, medium stiffness and heavy shaft). Ok, I had a good week's work,
> but the split times where back to 'normal'.
>
> Can anyone explain or share some more considerations when switching
> between light/heavy or soft/medium stiffness? Is one able to feel the
> shaft stiffness in more or less back pain?

I don't understand the terminology.

You describe your old oars as "medium stiffness and heavy shaft" and
your new ones as "'ultralight' type (not low-i), ... soft shaft"

Can you clarify these terms?

-KC

Henning,

My failure, or should I say my stupidity, to take into account the position
of the footstretcher has kept me from getting through the pins for a year.

Months ago, when I first got my boat, I complained about bumping into the
frontstops. The solution, of course, was simple, just move the tracks
further to the stern. This I did, and as a result I was able to spread the
oar handles further apart and get a little better angle at the entry. This
in turn gave me a slightly longer time to build up pressure against the
pins.

I remember at the time Paul's advising me to be careful not to move the
footstretchers too far astern. He reminded me of Steve Fairbairn's
admonition that "an oarsman must be careful not to bite off more than he can
chew." Bumping into the footstretchers would cue me that this was happening.

OK! So months ago I reset the tracks to allow me to get through the pins,
but then did something amazingly stupid. Instead of resetting the
footstretchers accordingly, I left them where they were. As a consequence I
found myself over compressing at the entry. In very short order I returned
the tracks to where they had been originally, and despaired about ever
getting more reach.

But last Thursday when I reset the tracks I had the advantage of another,
better brain helping. Gordon reminded me to reset the footstretcher at the
same time. And the rest is history, as they say.

I cannot believe how stupid I was not to have reset the footstretcher the
first time I reset the tracks!

Now, as for the question of using a less stiff oar, we had Gordon to dinner
last night and I took this up with him. I began the discussion by asking if
we could stipulate that when an oarsman bends an oar he stores energy in the
oar shaft?

Gordon agreed.

I then said that from past discussions on rsr it seemed to me this idea of
"stored energy" in an oar raised two important questions.

First, what percentage of "stored energy" would be returned?

And second, at what point in the stroke would it become available?

Again Gordon agreed.

"Those are the questions," he added, "and I don't think anyone can really
say for sure what the answers are."

"But doesn't everyone kind of sense that it is important to store some
energy in the shaft?"
Again Gordon agreed.

"Croker says that the stronger the oarsman, the stiffer the oar should be.
When I first read this I immediately thought of Odysseus' bow. When Penelope
carried the great bow into the suitors none was strong enough to string it.
Only Odysseus possessed that kind of strength. So my guess would be that you
should use an oar that you are strong enough to string."

Gordon laughed.

"Of course this still leaves the question, how much should you be able to
bend it? If you can't bend it at all, it probably is not going to do the job
you want it to. But, on the other hand, if you can bend it too much, it also
probably is not going to do the job you want it do. So how do you tell?"

It seems to me that the test with the Speedcoach is a good first step. If
you are getting 500m splits that you have never seen before, then why wouldn't
it be reasonable to assume that the new, less stiff oars are more suited to
your strength?

Of course there is probably a more scientific explanation, which I await
impatiently.

Cordially,

Charles

Henning,

I just reread some of the posts written in early June of this year about oar
stiffness. (see the thread "How I decided which new sculls to purchase" 1
June 2008.) This is something I probably should have reread before I replied
to you.

I must say that I am just amazed by the posts in that thread. It seems to me
that the contributions are exceptional. Consider Kieran's distinction
between a catapult and a diving board. But I don't want to single Kieran out
when there were so many other thoughtful and significant contributions.

Anyway, I highly recommend digging out this thread. Rereading it this
morning has been a pure joy.

More than ever I think that what you want in a blade is a shape that can
enter the water and lock on as quick and cleanly as possible, that can hold
on to the water all through the drive with minimum slip, and that can
release as quickly and cleanly as possible. If the new Dreissigackers with
their Smoothie2 blades + vortex, ultralights do this, then you have the
right tool.

I just love Gilbert Bourne's description of what is required of a rower:
"The oarsman should have a clear conception of what is required of him when
he makes his effort. He should understand, and be quite sure that he does
understand, that he is not so much required to set water in motion and
shovel it along past the side of the boat, as to stick the blade of his oar
as firmly as he can into a given spot in the water and to lift the boat as
far and as quickly as possible past that spot. His attention must be
concentrated on moving the boat, not stirring up the water."

And that, it seems to me, is what we want in an oar. Something that moves
the boat, not something that stirs up water!

Cordially,

Charles

KC schrieb:
> I don't understand the terminology.
>
> You describe your old oars as "medium stiffness and heavy shaft" and
> your new ones as "'ultralight' type (not low-i), ... soft shaft"
>
> Can you clarify these terms?

This is what C2 calls their products, and I haven't yet put hard numbers
next to them. The terms are all relative.

To summarise:
Old oars: medium (whatever that may be) stiffness, heavy shaft
New oars: low stiffness (ie softer), light shaft.

On Sep 5, 12:02 am, "Charles Carroll" <charles_carr...@comcast.net>
wrote:
> Spread cm                      158
> Total Oar length cm        287
> Inboard cm                      85
....
> Inboard is measured from oar handle to outside collar.

85cm inboard ??
Even considering 287 cm length, isn't that too heavy?

Mike,

While I will concede that 85cm for inboard is a trifle short, I believe that
it is within an acceptable range. In other words, it seems to me it is not
radically short.

Don't forget, too, that the spread is 158cm, which is slightly shorter than
a conventional 160cm spread, but still well within an acceptable range. I
think, if I have not misunderstood everything, that you can get away with a
shorter inboard if you have a shorter spread.

The benefit from a shorter inboard is that I can get a wider separation
between the handles at the entry, especially now that I can come through the
pins. Doesn't a wider separation between the handles translate into more
length? If so, then doesn't this give me a few more milliseconds to apply
pressure to the pins?

I believe Carl has written about this. The temptation is to try to pull
through harder during the drive so that the drive feels the same as it did
when the inboard was 86cm. My goal is to avoid this temptation and just
enjoy the benefit of the few more milliseconds on the pins.

But will all this result in being able to move the boat faster? The only
thing I can say is we'll see.

Cordially,

Charles

On Sep 8, 7:04 pm, "Charles Carroll" <charles_carr...@comcast.net>
wrote:
> While I will concede that 85cm for inboard is a trifle short, I believe that
> it is within an acceptable range. In other words, it seems to me it is not
> radically short.

It seems to me, that I'm using 88cm, and where it's more common to use
90cm

> Don't forget, too, that the spread is 158cm, which is slightly shorter than
> a conventional 160cm spread, but still well within an acceptable range. I
> think, if I have not misunderstood everything, that you can get away witha
> shorter inboard if you have a shorter spread.

Sure, in fact I use 157cm, where it is more common here to use 160-90

> The benefit from a shorter inboard is that I can get a wider separation
.... (speculations) ...
> But will all this result in being able to move the boat faster? The only
> thing I can say is we'll see.

let me know how it goes :-) and what you back will tell you about your
heavy gearing

On Sep 9, 10:03 am, Mike De Petris <mikedepet...@gmail.com> wrote:
> On Sep 8, 7:04 pm, "Charles Carroll" <charles_carr...@comcast.net>
> wrote:
>
> > While I will concede that 85cm for inboard is a trifle short, I believethat
> > it is within an acceptable range. In other words, it seems to me it is not
> > radically short.
>
> It seems to me, that I'm using 88cm, and where it's more common to use
> 90cm
>
> > Don't forget, too, that the spread is 158cm, which is slightly shorter than
> > a conventional 160cm spread, but still well within an acceptable range.I
> > think, if I have not misunderstood everything, that you can get away with a
> > shorter inboard if you have a shorter spread.
>
> Sure, in fact I use 157cm, where it is more common here to use 160-90
>
> > The benefit from a shorter inboard is that I can get a wider separation
>
> ... (speculations) ...
>
> > But will all this result in being able to move the boat faster? The only
> > thing I can say is we'll see.
>
> let me know how it goes :-) and what you back will tell you about your
> heavy gearing

That strongly depends on the distance raced/the rating he wants to
attain, surely? I always liked having my (C2 smoothie) sculls on
284/160/85, or sometimes 84, in the winter, and while I was mostly
only using the single for steady-state at 18, or the occasional long
time-trial/head race at 28/30, that was great; the few times I've got
out of a sweep boat during the summer and raced regattas in a single,
I've discovered I needed to get a load more inboard back to rate high
at full length.

The reasoning behind my slightly odd choice was mostly forced; with
very short legs, on the standard (at school) rig of something like
287/160/87 even with the feet as far bowwards as they would go the
blades were still virtually overlapped at the finish, which I found
awkward.

If the occasion ever comes when I get my own sculling setup, I suspect
I'll try some radically shorter blades and then proportionally
adjusted span/inboard; if I'm 15% shorter than some of the people
rowing on that rig, would 15% shorter blades not make sense?
Investigating whether anyone is willing to make me 240-250 would be a
possible problem, however... not to mention riggers with an spread of
133.

However, at the moment I'm moving further from sculling to sweep, so
it doesn't look like an imminent decision to make.

Peter Ford