Shims...what's right?
Miceband
2 oarlocks. I've been told this is severe; that 4 or 5, sometimes 6 but never
7. Anyone know for certain?
John Mulholland
between zero and two degrees outwards for lateral pitch. The only reason I
can see for these shims is to correct for oars with considerable pitch on
them (allowing stroke-side Macons to be used on bow-side?!?).
John Mulholland
Hexham Rowing Club
"Miceband" <mice...@aol.com> wrote in message
news:20030609113410...@mb-m25.aol.com...
Walter Martindale
Has anyone put a level across the gunwale and checked lateral pitch on
the pins? I've been setting boats to vertical pins for so long, now, I
just vaguely remember why people would have lateral pitch on their pin.
(it's to keep from digging at the entry and to keep in the water
towards the finish).
Put a level across the boat, check that the pins are vertical relative
to the beam of the boat.
Either level the boat stem to stern, and check that the pins are
vertical relative to the waterline, or use a pitch meter to see if there
is "zero" fore-aft pitch.
If there is a pitch to the pin, can you bend the rigger or adjust it so
that the pin is vertical.
Are the blades also zero pitched, and do you know how to check them (it
depends on what brand and shape of oar you have) - if not, how far off?.
A small amount can be shaved off the "high" side, a large amount
requires removal of the sleeve-wear plate assembly and
re-glue-reassemble in the right position. Often best done by someone
from the factory, or who has been trained by a factory rep. If you
really need it, and if I can find it, I can send you a document I wrote
for the NZ Rowing mag a few years ago about maintenance of oars (it was
vetted by Howard Croker).
For example - Howard Croker recommends a vertical pin and 3 degree pitch
settings in the oarlocks for his "slick" blades. Concept 2 seem to feel
(to the athletes) best at either 3 or 4 degree settings.
Can't really speak for Braca or any of the other brands.
Hope this helps.
Walter Martindale
Anu Dudhia
"4" is normal (assuming that the pins are vertical).
Back in the old days before shims were invented, wooden oars usually had two
degrees twist built in and the swivels 4 degrees, making 6 degrees in total, but
now everyone seems to manage quite happily with a couple of degrees less.
Henry Braun
> > My club boat, a racing shell with tubular rigging, has #7 shims in the
> > Concept 2 oarlocks. I've been told this is severe; that 4 or 5,
> > sometimes 6 but never 7. Anyone know for certain?
>
> "4" is normal (assuming that the pins are vertical).
Some Concept II shims (is that what they're called? We've always referred
to them as "inserts") are marked 4 if they're straight, 5-3 for 1 degree
of pitch adjustment, 6-2 or 7-1 for three degrees of adjustment. Others
are marked 1 for 1 degree, etc, or are unmarked if they're straight. It
can take a keen eye to pick out the right one.
In an emergency---and they seem to crop up all the time---you can use the
5-3 (aka 1) inserts back-to-back to simulate a pair of straight inserts.
Probably this damages them, but it's fine to row with.
Ewoud Dronkert
>Some Concept II shims (is that what they're called? We've always referred
>to them as "inserts") are marked 4 if they're straight, 5-3 for 1 degree
>of pitch adjustment, 6-2 or 7-1 for three degrees of adjustment. Others
>are marked 1 for 1 degree, etc, or are unmarked if they're straight.
Really? I only know the first variant, 4-4 = straight. See
http://www.triton.studver.uu.nl/img/dop.jpg We call them "doppen",
caps or buds in English. 4-4 is straight because the number refers to
the total angle of inserts + oarlock, and recent oarlocks are always 4
degrees.
>In an emergency---and they seem to crop up all the time---you can use the
>5-3 (aka 1) inserts back-to-back to simulate a pair of straight inserts.
Right, but we always seem to have 4-4 to spare, and never enough 5-3.
BTW, you can also adjust for half a degree by using 4-4 and 5-3 in one
oarlock.
John Whyte
> Some Concept II shims (is that what they're called? We've always referred
> to them as "inserts")
I think 'Shims' are the little plastic sticker type things which are used to
ensure a tight fit when using adjustable handles..??
Neil Wallace
"Never 7"???
That begs the question - why do they make them then?
and remember, should you choose to put them in an oarlock backwards
(accidentally or otherwise) turns that into a 1 degree set up.
so you can choose between 1 degree and 7 in 1/2 degree steps WRT the pin.
Can be very useful given the variety of pitches blades have on them (mine
are both 2.5 degrees positive, for instance).
but to answer your point directly, my (limited) understanding is that modern
rigs are normally pin vertical in both directions, and (gate+oar) is 4
degrees for a big blade, 6 degrees for macons, and 2 or 3 degrees for a
"variable-pitch" smoothie type blade.
rigging experts (Chalky?) feel free to jump in and correct.
Neil
Carl Douglas
>
>"Miceband" <mice...@aol.com> wrote
Oarlock insert bushes (C-II) or shims (e.g. Martinoli, Stampfli) are
there to serve 2 requirements:
1. Coach wants the crew to row on other than the 4 degrees of blade
pitch you'd get on C-II if you used zero-pitched oars & oarlock bushes
with dead-central holes.
2. Not every oar has the pulling face of its sleeve exactly at 0 degrees
(= aligned) to the blade, due to manufacturing or re-blading errors.
Oarlock insert bushes will _not_ correct for errors in pin stern-pitch,
despite that misconception being a widely held. If your pin's stern
pitch is not zero, then you can make the mid-stroke pitch correct by
changing oarlock inserts but you will make the pitch increasing wrong
towards both ends of the stroke - which is not very helpful.
For correct & accurate blade pitch setting you must be able to set pin
pitch (stern _&_ lateral) & oar/oarlock pitch independently. These
different elements of the oar-blade pitching system are _not_
interchangeable:
1. Whatever change you make to the relative alignment of blade & oar
wear plate, or to the pitch inserts on the oarlock, will appear at the
blade equally at every part of the stroke. A 1-degree increase in
oarlock pitch increases blade pitch by 1 degree throughout the stroke -
from what it had previously been.
2. If you incline the pin off-vertical, directly away from the boat
(lateral pitch), you will not affect the blade pitch in the water at
mid-stroke, but you will increase that pitch at the catch (by about 70%
of the amount of lateral pitch you have on the pin) & reduce it at the
finish (by about 50% of the lateral pitch)
3. If you add stern pitch to the pin, you will increase the blade pitch
in the water at mid-stroke by an identical amount, but only by about 40%
of the added stern pitch at the catch and about 60% of the stern pitch
at the finish.
A sensible rigger system offers low resistance to wind & water &
provides a rigid platform which carries a pin giving independent
adjustment of its stern & lateral pitches by a calibrated & secure
mechanism which cannot slip in use or under any other loading. The
rigger system is AeRoWing. The pin is called AxioR.
:-)
Carl
--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
Email: ca...@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)
Adrian Turner
> (lateral pitch), you will not affect the blade pitch in the water at
> mid-stroke, but you will increase that pitch at the catch (by about 70%
> of the amount of lateral pitch you have on the pin) & reduce it at the
> finish (by about 50% of the lateral pitch)
Not knowing much about lateral pitch.. what's a good angle to aim for?
I know 4 degrees is widely quoted for stern pitch, but what about lateral
pitch?
Cheers,
Adrian
Edd Edmondson
C2 calls the things inside the oarlock 'bushings'.
--
Edd
Miceband
go any further than place lesser shims in the oarlocks. I AM going to check
for vertical pin on the level, though. Thanks again.
Miceband
As to the pins being vertical, I'll have to check with Paul Neville, one of the
owners of the company. He keeps quite a concise record on all his boats.
Thanks.
Miceband
oarlocks/swivels are neutral. The inserts/shims, are pressed into the whole of
the oarlock/swivel and then once slid onto the pin accomplish the ultimate
required pitch. They are coded by use of colors--#7 is blue, others black, etc.
John Maxwell
vertical in both the fore-aft and lateral directions. As the the angle
we set the gate pitch to, that depends on crew, equipment etc.
Miceband
particular club boat--a Janousek, with a welded rigger and therefore
non-adjustable. Once I've done that, I can decide just how much pitch is
actually in effect by factoring in the #7 shim presently on the boat?
Henning Lippke
> provides a rigid platform which carries a pin giving independent
> adjustment of its stern & lateral pitches by a calibrated & secure
> mechanism which cannot slip in use or under any other loading. The
> rigger system is AeRoWing. The pin is called AxioR.
Do you have some kind of a manual with 'try these' or 'standard'
settings to play with?
-HL
Ewoud Dronkert
>Do you have some kind of a manual with 'try these' or 'standard'
>settings to play with?
Zero and zero. Or MAYBE one degree lateral (outward).
Andy Hadcroft
If it's a 13 yo club boat I'd lay very good odds that pins have shifted a
bit since the shell was first fitted out - many riggers tend to pick up
dents and bends over time which can have significant effects on pitch (and
height). You need to measure what they're like now!
Anu Dudhia
I thought the difference between the blue and black ones was just the diameter of
pin?
Anu Dudhia
> Not knowing much about lateral pitch.. what's a good angle to aim for?
> I know 4 degrees is widely quoted for stern pitch, but what about lateral
> pitch?
2 degrees always used to be the quoted figure. Not that you normally get
much choice in the matter as most riggers have fixed lateral pitch built
into the pins anyway (Aerowing riggers being the main exception).
Neil Wallace
"Andy Hadcroft" <REMOVEandr...@THESEpath.ox.ac.uk> wrote in message
news:bc8eot$spf$1...@news.ox.ac.uk...
> If it's a 13 yo club boat I'd lay very good odds that pins have shifted a
> bit since the shell was first fitted out - many riggers tend to pick up
> dents and bends over time which can have significant effects on pitch (and
> height). You need to measure what they're like now!
>
Absolutely... very important to check the pins once in a while if the boat
is used by others.. you never know if they been whacked or buggered about
with.
may I give you a tiny little tip which worked for me but may be laughed at
by others here....?
From a DIY store buy a good length of 13mm copper pipe. (harder metal would
be even better). Choose a piece that is absolutely straight by rolling it on
the floor.
Take it home, cut it in half.
At the boathouse, take off the oarlocks and any washers. Put the pipes onto
the pins (they should fit just dandy).
What you have now is a boat with pins which are about 1m high. makes it
really easy to use your eye to check for any deviation from vertical.
In fact, if your boat is level in both directions, use a plub bob from the
rafters to double check.
better than any pitch guage IMHO... but you do need that to check the oar
sleeves.
Miceband
oars/doppen caps/buds/bushings...yes to different diameter pins (Thank you
Bob...and Anu!)...;-)
Miceband
Walter Martindale
I can't exactly remember what our late 80's Janouseks riggers looked
like, but if I remember correctly, the lateral pitch is dependent on
where a hole was drilled, and the stern pitch depended on the adjustment
of a clamp and the amount you've rotated the sleeve in which the pin is
threaded. Lateral pitch may be "what you've got" .
If it's a stainless pin bolted to a welded plate - preferably not
aluminium - you can slide a bit of pipe over the pin and use a carefully
applied bit of "english" to make the lateral pitch "zero".
You may want to measure the lateral pitch and live with whatever it is,
and adjust fore-aft pitch to zero. Or, you may want to talk to Carl
Douglas about some retro-fit riggers.
Walter