setting pitches
Boom1971
I have been shown by a colleague how to aprroximately rig a boat, but
no-one here seems sure how to set the pitch and the effect that changes
will have.
Does anyone have any info??
Thanks in advance
Ashley Dillon
Cindy Parker
Yeah - here's a reply (though I know I am subject to extreme judgement)
It depends on the type of riggers:
Vespoli types, Kaschper types, old Schoenbrod types, or Old Pocock types...
The pitch is extremely important to the crew's ability to set-up the boat. Basically,
the pitch allows each oarsman his "2 cents" in applying "righting force" to help
setup the boat. Nothing replaces good timing/finish pressure in setting-up the boat
though.
As an oarsman pulls through the water, the pitch provides allows the oar to
contribute a bit to the support of that side of the boat. The more pitch, the more
that oar lifts that side of the boat. It also allows for a feeling of "buoyancy"(SP?)
in the oar, so the oar doesn't feel like it's going to dive into the water. Good
crews can be set with less pitch(3-4 deg) because thier timing and hand-level
adjustments are more refined. Novices need lots-o-pitch(6 degrees), unless you
believe they learn by flailing...
You can adjust pitch on old pocock riggers by inserting washers under the pin, or
under the brace (you're changing the lengths of two sides of a triangle.)
With the new CII oarlocks with pitch inserts you only need to set the pin to 0 deg
pitch, and put in the appropriate insert into the oarlock.
But if you've neither system, you need a pitch meter (which is relatively easy and
cheap to make), and a couple wrences, and a tape measure.
I'll take a stab at describing the process, but be sure to check out a book or two,
and fellow caoches:
1) Remove the backbrace from your way by removing the "top nut" or "top bolt" from
the pin of the oarlock, and stick the member up in the air(the long tube from top of
oarlock to bow-end of track on side of boat);
2) Loosen bolt that is holding pitch angle a bit, enough so it holds a position, but
you can move it without difficulty with your hands:
a) On old Schoenbrod riggers, this is a big piece of aluminum that the pin goes
through, loosen the nut on the bottom;
b) On Vespoli/Dirigo riggers, loosen the 'C' shaped plastic or Aluminum clamp that
wraps around the main rigger tube;
c) If these are riggers with the pin in a SLOT that runs perpendicular to the boat,
ask someone else what to do IF IT ISN'T 0 DEGREES ALREADY!
3) Set the SPREAD by moving the pin in and out from the boat, measured from the boat
center-line. You'll want to consult another experienced rigging-type about specific
measurements, but about 85-86 cm is fine to start with. If you accidentally hit the
pin before tightening it, the spread won't change much;
4) Now, with a pitch meter, set the meter in the boat or on the gunwail so the level
is parallel to the centerline of the boat. Put the big pointer on 0, and hold it with
a thumb. Move the level so the bubble is in the middle;
5) Take the meter and put it on the pin in the same orientation as it was in the
boat. The flat face of the side of the meter should be flat against the pin, and the
meter should be in line with the boat.
6) Move the pin (not the pointer on the meter) so the bubble becomes level.
7) Carefully remove the meter, and TIGHTEN THE HELL out the bolt that holds the
pitch.
8) Put back on the washers and oarlock, move the back brace so it's on top of the pin
and adjust the back-brace's length so the hole matches the hole of the/pin. Put on
and tighten the bolt/nut, and tighten the fittings on the back-brace so it doesn't
loosen. Make sure all rigger nuts are tight.
I hope this helps, If anyone has any comments please let me know through the
newsgroup...
Sean Parker
Nov Men's Coach
Langley HS
(Occoquan VA)
Duncan Barton
Cindy Parker wrote:
<snip>
> 4) Now, with a pitch meter, set the meter in the boat or on the gunwail so the level
> is parallel to the centerline of the boat. Put the big pointer on 0, and hold it with
> a thumb. Move the level so the bubble is in the middle;
>
> 5) Take the meter and put it on the pin in the same orientation as it was in the
> boat. The flat face of the side of the meter should be flat against the pin, and the
> meter should be in line with the boat.
>
> 6) Move the pin (not the pointer on the meter) so the bubble becomes level.
>
> 7) Carefully remove the meter, and TIGHTEN THE HELL out the bolt that holds the
> pitch.
<snip>
> Sean Parker
> Nov Men's Coach
> Langley HS
> (Occoquan VA)
Not being familiar with many of the American brands of rigger I cannot comment on the
beginning of this post, but is sounds reasonable. I do have a couple of comments about the
above though.
The method above assumes the pitch is in some way set by a mechanism within the gate itself
e.g. the Concept ][ or Martinoli insert systems. With older style gates, the pin has to be
"angled" to give the correct pitch. With either system I prefer to measure the pitch on the
gate rather than on the pin - particularly if the gate is worn and there is some play.
I zero the pitch guage as described and then the required pitch is be "dialed up", i.e. you
move the pointer on the pitch guage to 3deg for example, and the pin would be adjusted until
the bubble becomes level. Alternatively, with the Concept ][ or Martinoli system you can
change the inserts until the desired pitch is reached. Either way, make sure the pitch on the
gate is the one you want, at the gate.
Also I always check the lateral pitch of the pin - the lean into or away from the boat. I
prefer it to be 0deg and have been caught out on a couple of occations when I have been slack
and not checked it. Lateral pitch will effect the "normal" pitch through the stroke - from
memory (and I could very well be wrong) if the pin is leaning out the pitch will decrease
through the stroke and vice versa. Many coaches in this neck of the woods like a 1deg outward
pitch, to help hold the blade in at the release.
The easiest way to measure the lateral pitch is with two spirit levels - one the builders size
and the other a small 6" level or the pitch meter. Use the large pitch meter lain accross the
gunnels to ensure the boat is level and use a zeroed pitch meter (zeroed to the perpendicular
to the centre line of the level boat) or the small level to check the pins are vertical. It is
often helpful to have a second pair of hands to help with this part of the proceedure or if
you do your pitching outside on a grassed area, bang a couple of posts into the grass and tie
two of the riggers to them when the boat is level - doesn't work so well with concrete or
wooden floors!
Hope this helps,
Duncan
e-mail: dba...@earwax.pd.uwa.edu.au
The only problem you will not conquer is the one you fail to face.
Gerard Ashton
I have a related question. A few people suggest zeroing the pitch
meter on the boat deck or gunwale. However, I took my Alden Star
out in the water, and brought along a small carpenter's level.
With me in the boat,
I tried the gunwale, the seat deck, and the bottom of the cockpit,
but couldn't find a place that was level from stem to stern.
I even tried sliding the seat back and forth; still no luck.
I called Alden; they suggested using the seat deck.
Any suggestions?
--
Gerard Ashton
George Kirschbaum
The big things in setting pitch correctly depends on the
experience of the crew, and type of blade shape that is being used. I
agree with Sean that novice crews need more pitch. When it comes to blade
shape, the big blades can be pitched with much less pitch than the
macons. I doubt I'd pitch a macon blade much less than 5 degrees, but big
blades as little as 3.5 degrees. Right now my HS varsity hvy, and lwt 8's
are both pitched at 4 degrees with big 25/52's. Keeps the blade barried
through the finish, but requires better finish technique. . . I also
agree that pitch can effect set, because if the entire crew is not
finishing and releasing at the same time, it is going to throw the set
off to one side or another.
.02
George Kirschbaum
Head Coach, Gonzaga College Hs.
Michael Hawkins
Duncan,
An interesting exposition. Would you mind demonstrating on the
"Berryman"?
Robert Plater
Remember that when your on the water the boat will not sit even
(bow-stern) unless the weight is PERFECTLY distributed. So if you bow is
heaveyer than your stroke, the boat will slope towards the bow.
This is why you pitch on land. You creat the idea circumstances.
REputible boats will have the gun level all the way round. Think about
it for a sec, it's what the boat sits on when on the rack. The deck
isn't as reliable as they are put in after the molds is set.
In otherwords, measure level off the gun off the water.
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Robert Plater
University of New South Wales
robp...@geocities.com
~O_ ~O_ ~O_ ~O_ ~O_ ~O_ ~O_ ~O_ o~
______(___(_/_(___(_/_(___(_/_(___(_/____)________
/ / / /
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Robert Plater
True about Novices being pitch greater. Also remember that the closer
the pitch is to 0deg the more efficient the stroke. More pitch allows
more slip in the water, which is somtimes a good thing.
GSpiess
I always measure off the gunnals or the keel, because many boats have a
slight incline at the seat deck. This has bothered me - and I ask your
opinion. With an inclined seat deck, where the rower is lower at the
catch and higher at the finish, should we measure at the deck to account
for this non-level angle? I am surprised at how many boats have this
feature. I wrestle with this, versus the fact that the water level
doesn't change during the stroke, so why consider the change in seat
height during the drive when adjusting the pitch? Given what I know about
the mechanics of rowing, I don't really understand why seat tracks have
this incline anyway. Your thoughts?
George Kirschbaum
I always use the gunnel, since it should be at the same angle
relative to the rigger. Makes sense if you figure the rigger is bolted to
it. . .
George
C&S Parker
Regarding angle of track bed, I'm not sure how it started, but it sure would feel
strange to change it!
Some boats have the angle built-into the boat (there aren't any risers under the
track) and some have "level" track beds, with risers.
I always measure pitch using a level track-bed or gunwail as reference. The boat
designers design a level gunwail into the boat. If your gunwail isn't level with a
crew in it, redistribute the crew in the boat. I would also suspect that the level of
design has reached a point where the hull is most efficient when in the water level,
and *a little* less efficient in other angles. The difference being maybe a tenth of
a second in 2000m? who knows...
John Woffinden
In article <19970501130...@ladder01.news.aol.com>, GSpiess
<gsp...@aol.com> writes
I have wondered this as well. Perhaps on answer is that the water level
DOES change - as the crew move through the stoke their weight moves
forward thus causing the bows to dip slightly (perhaps most noticable in
a single) and therefore changing the hight of the seat with respect to
the water. The incline on the seat track may compensate for the angluar
movement in the boat?
This probably depends on lots of other factors like the position of the
centre of bouyancy with respect to the seat, the anount of lift the hull
shape generates as it accelerates etc...
Any one got any further thoughts on this?
--
John Woffinden
jo...@maidenheadrc.demon.co.uk
Maidenhead Rowing Club
http://www.maidenheadrc.demon.co.uk/
GSpiess
But not all gunnals are level in relation to the water line. On the
extreme side, I can think of the Coffey single, where the gunnal is very
angular. I also think, although I have not confirmed, that the VD
Advantage gunnal is not level with the water. I think that you basically
have to "eyeball" a level surface and take your readings off of that, then
confirm your settings on the water by judging how it feels and how the
blade travels. This is not easy if you're rigging for novices who don't
know good rigging from bad, but what else can one do?
I hate to sound fatalistic, but I remember an older rigger once telling me
that you "just set it 'till it looks right." There is more truth in that
statement than I was willing to admit at the time.
George
Jay Feenan
In article <19970516063...@ladder02.news.aol.com>, rodl...@aol.com (Rod Lawson) writes:
|> In article <19970515142...@ladder02.news.aol.com>,
|> gsp...@aol.com (GSpiess) writes:
|>
.
.
.
|> I agree completely. If what the pitch guage tells me doesn't fit what it
|> feels like,
|> I usually just keep measuring it untill it does. I find it's also striking
|> just how
|> accurate you can be by eye. Although it's difficult to believe you can see
|> an odd
|> degree more or less, a good rule of pitching seems to be if it looks
|> wrong, it's
|> wrong, and if it looks right, it's not far off.
|> Rod.
|> Disclaimer; the opinions expressed above are not necessarily yours.
Actually most times that I hear this, the sculls [oars] are 'warped'. I've seen
'brand new' sets have a +/- of a couple of degrees. One national teamer
complained about his boat 3/4 months and got kicked out of a number of boathouses
having people 'look at the rig'. One day while practicing with him I asked if he
ever check the oars....two hours later we had the problem fixed.
Many 'old timers' use a plumb line with a tape measure on the blade to account
for this in their pitch analysis.
-Jay Feenan
Rod Lawson
>I hate to sound fatalistic, but I remember an older rigger once telling
me
>that you "just set it 'till it looks right." There is more truth in that
>statement than I was willing to admit at the time.
I agree completely. If what the pitch guage tells me doesn't fit what it
lanclarke
GSpiess
Jay Feenan makes an excellent point. There are a lot of oars out there
that are not neutrally pitched. Not long ago it was typical for oars to
be made with a pitch built in, and these blades are still around. The
warpage that he mentions is also a factor, and I once mistakenly put a
slight pitch in a pair of CII sculls when I was upgrading the collars and
took my level from the wrong surface. Mentioning the plum line reinforces
that rigging "purists" measure at the blade, not the swivel.
George
S.B.Hobdell
Okay, so if we should actually measure the pitch on the blades, do we
measure it at the top or the bottom of the spoon?
I had this problem when I had to set the pitches up for a crew a few
years back. It was the first time I'd heard the 'measure the pitch on
the blades' concept, having always pitched the riggers to 4 degrees.
I was told that what I thought was 4 degrees on the blades was actually
6 degrees. This could have been caused by my putting the pitch gauge
too far down the spoon (which curve slightly), or just being crap :).
So, in summary, where??
Steve Hobdell
Uni. of Wales, Bangor RC, UK
p.s., the blades were heavy-ish concept II's cleavers,usually made
with zero pitch, I believe....
Jay Feenan
In article <3381DE...@bangor.ac.uk>, "S.B.Hobdell" <eep...@bangor.ac.uk> writes:
|> Okay, so if we should actually measure the pitch on the blades, do we
|> measure it at the top or the bottom of the spoon?
|>
A number of pitch meters out there allow you to rotate the meter 90 degrees so
that the part that touches the blade is longer and extends top to bottom on the
blade. If you have a meter that does not allow that I would try and measure it
from the center of the blade of just further out than the spline on a hatchet
[which is not on the center].
> I had this problem when I had to set the pitches up for a crew a few
|> years back. It was the first time I'd heard the 'measure the pitch on
|> the blades' concept, having always pitched the riggers to 4 degrees.
|>
|> I was told that what I thought was 4 degrees on the blades was actually
|> 6 degrees. This could have been caused by my putting the pitch gauge
|> too far down the spoon (which curve slightly), or just being crap :
You might have measured correctly, but have blades that are pitched 2
degrees...we still have a few sets this way around the club [most of the older
wooden sets were this way...as indicated before].
-Jay Feenan
Rod Lawson
In article <19970520131...@ladder02.news.aol.com>,
gsp...@aol.com (GSpiess) writes:
>Jay Feenan makes an excellent point. There are a lot of oars out there
>that are not neutrally pitched. Not long ago it was typical for oars to
>be made with a pitch built in, and these blades are still around. The
>warpage that he mentions is also a factor, and I once mistakenly put a
>slight pitch in a pair of CII sculls when I was upgrading the collars and
>took my level from the wrong surface. Mentioning the plum line
reinforces
>that rigging "purists" measure at the blade, not the swivel.
In fact ideally you should measure the pin and set it to be vertical,
then put in the insert you require and check that's right
on the spoon, changing the insert of it's necessary because of warp. Or
maybe that's what you meant?
Anyway, the point is that if the pin isn't vertical the pitch changes
through the
stroke. You can put in a bit of lateral if you like that, but if the pin
is off
other way on, the pitch varies inconsistently thorugh the stroke. So you
can't
just measure from the spoon either. You have to take off the gates, set
the pins,
put the gates on with the inserts, and THEN check the spoons, adjusting
the
insert to compensate for any warp if necessary.
Or alternatively just set it so it looks right.
Hamilton Richards Jr.
In article <337fa...@newserv.parkave.net>, lanc...@parkave.net wrote:
> gsp...@aol.com (GSpiess) wrote:
>
> >Given what I know about
> >the mechanics of rowing, I don't really understand why seat tracks have
> >this incline anyway.
It makes recovery easier, at the expense of making the drive a little
harder. But the muscles we use in the drive are much stronger, so it's a
good trade-off.
To really appreciate the difference that slight incline makes, try rowing
a boat whose tracks are level for example, an Alden Ocean Shell). If
you're used to inclined tracks, a flat-tracks boat feels "dead".
--Ham Richards
------------------------------------------------------------------
Hamilton Richards Jr. Department of Computer Sciences
Senior Lecturer Mail Code C0500
512-471-9525 The University of Texas at Austin
Taylor Hall 5.116 Austin, Texas 78712-1188
------------------------------------------------------------------
S.B.Hobdell
Jay Feenan wrote:
> |>
> |> I was told that what I thought was 4 degrees on the blades was actually
> |> 6 degrees. This could have been caused by my putting the pitch gauge
> |> too far down the spoon (which curve slightly), or just being crap :
>
> You might have measured correctly, but have blades that are pitched 2
> degrees...we still have a few sets this way around the club [most of the older
> wooden sets were this way...as indicated before].
>
> -Jay Feenan
No, the blades were the old style Concept II hatchets without pitch...
and I measured them on the spoon, so the difference could have been due
to measuring at different heights up the spoon. Thanks for the response
anyhow, Jay,
Steve Hobdell
Uni of Wales Bangor RC, UK
Jay Feenan
RE: Vertical pins.
Sorry I assumed vertical in my previous message. If an oar is 'warped' then with
today's oars it is due to the collar being a degree off from the blade. If it
only a degree or less you can shave the top or bottom part of most collar designs
to get rid of the extra pitch [assuming hatches...some people with macon blades
would actually want to switch port/starboard blades every once in a while.]
If it is more I wouldn't fool with different degrees of pitch on each side of the
boat and would fix the collar problem on the shaft. It just makes it easier
jumping between different boats/seats and using the same oars.
If you like vertical pitch then...just ensure that it is the same on both sides.
-Jay Feenan
Ryan Webster
Always from the gunwales, I'm sure most have told you. On boats with
flat decks, there are usually wooden shims under the tracks. This is a
mechanical necessity, to keep a constant height. Without them, as a
rower moves away from the pin into the bow, his hand-height would have to
rise to keep the blade in the water. With the incline, a rower can
concentrate on what 'seems' to be a horizontal pull-through. The incline
has nothing to do with pitch, and thus should not be taken into account.
-
RYAN WEBSTER RGX...@prodigy.com
David Powell
It doesn't rally matter where you take the datum point. What really matters
is that you have set the crew the same relative to each other to start
with. On a Janousek single the only place that I can take as a datum is the
keel on the bottom of the hull. you can see that the saxe-board is not
straight. If you want to get into a techie discussion, try talking about
scullers setting their spans!
Ryan Webster <RGX...@prodigy.com> wrote in article
<5mdfuo$1h...@newssvr01-int.news.prodigy.com>...