22 Dec 2006 00:57:15
Pete W
Adjusting the rigging for a men's club 8 - advice needed.

Hi,

I measured an eight that is used by our club's first 8 last weekend and
i find i need some advice.

i can measure a boat well enough and to within the recommended in
ARA/Fisa publications but much beyond that i can't do.

when i asked the lads to get the shell off the rack and measured it i
found the 7 & 4 seats very high (20.2 cm) and the rest of the boat
round about 19cm. i thught this was too high and bought it all down to
17 cm.

after the 1st outing it was obvious this was too low for the 7 & 4 men
and we re-adjusted the heights to 18cm after the 1st outing. this was
fine for the 4 man but after the 2nd outing we took the height as far
we could for him - back to 20cm. And he still looks like he rowing too
low.

the plated weight for the shell is 95kgs and the average weight of the
crew is 88.9 kgs.

what worries me is there is a flaw in the shell - could it have
twisted?
or is there somethign i am doing wrong? (more than possible)

any ideas i can investigate when i am next at the club would be
gratefully received!

Cheers,
Pete



22 Dec 2006 01:22:09
Re: Adjusting the rigging for a men's club 8 - advice needed.


>
> any ideas i can investigate when i am next at the club would be
> gratefully received!

Have you tried checking that the ribs that the rigger are bolted onto
aren't broken or very soft at those seats? Extreme I know, but we had
a similar problem with one of our boats. The oarlocks were set up to
the same effective height on dry land, but then in use, the oarsman at
the seat in question found it was "low" - but this was because the boat
was flexing across the main rib so that there was no real control over
the height of the oarlock at the finish and in the tap down.
Sometimes, without thinking about that possibility, the assumption is
made that the oarlock is simply set low, so then the rigging gets
raised to give more hypothetical clearance, and it *still* rows low.
With the boat upside down on trestles, try lifting it from the outboard
rigger end. An intact rib will allow you to partially lift the boat.
A bust one will move without the boat lifting immediately - you will be
able to tell the difference fairly quickly.



22 Dec 2006 01:54:52
Teaplant
Re: Adjusting the rigging for a men's club 8 - advice needed.


you might want to consider the different geometries of your oarsmen...
an important factor is their 'seated height'... a 6ft tall athlete may
have long legs and a short back (a giraffe) or short legs and a long
back (scooby doo!). these people would need very different rigs for
comfort and efficiency.
I would do exactly what you are doing - check it over and square it all
up first. Then trial and error to fine tune. Key landmarks are
hand/elbow/shoulder position at the finish (check with all 8 at
backstops buried and square) and hands clear of the thighs through the
recovery (check with four holding at a time and eyeball it). if
everything *looks* ok and *feels* ok to coach and rowers then it is
probably ok.
So long as the boat is not too floppy and the pins are all upright with
TDs correct (can of worms), you will then be pretty close to optimum
for your crew. Beyond that you are better off training harder than
getting too scientific .
On a related note, I have often noticed my stern pairs prefer a little
more height than the rest, although on the paddle this seems
over-generous. At pace it comes right... is this the boat trimming
differently at speed?

teaplant.



22 Dec 2006 12:02:07
Carl
Re: Adjusting the rigging for a men's club 8 - advice needed.

Teaplant wrote:
> you might want to consider the different geometries of your oarsmen...
> an important factor is their 'seated height'... a 6ft tall athlete may
> have long legs and a short back (a giraffe) or short legs and a long
> back (scooby doo!). these people would need very different rigs for
> comfort and efficiency.
> I would do exactly what you are doing - check it over and square it all
> up first. Then trial and error to fine tune. Key landmarks are
> hand/elbow/shoulder position at the finish (check with all 8 at
> backstops buried and square) and hands clear of the thighs through the
> recovery (check with four holding at a time and eyeball it). if
> everything *looks* ok and *feels* ok to coach and rowers then it is
> probably ok.
> So long as the boat is not too floppy and the pins are all upright with
> TDs correct (can of worms), you will then be pretty close to optimum
> for your crew. Beyond that you are better off training harder than
> getting too scientific .
> On a related note, I have often noticed my stern pairs prefer a little
> more height than the rest, although on the paddle this seems
> over-generous. At pace it comes right... is this the boat trimming
> differently at speed?
>
> teaplant.
>

The points made so far are well made & most relevant. A further
important consideration is: how are you measuring those heights?

If, like almost every coach, you're using a height stick, do you really
know that the tops of the saxboards (US = gunwales) are straight & level
along the boat? We rigged up a brand new Boat Race eight &, during
measurement, I saw that one saxboard had a marked droop in the vertical
plane. The effect was that, if all riggers were actually at the same
height, when measured by height stick they'd seem to vary along the
length of the boat by over 1cm between the ends of the boat & the
middle. That meant #5 on bowside seemed >1cm low & #4 on strokeside
seemed 1cm high. I measured all sax bevel angles with a digital level &
pointed out the sax droop to the boatman, asking what the club'd do
about it. Their decision was that we should make the riggers & they'd
live with the problem - even though that problem would be with that boat
wherever it went.

On an eight, a 5mm differential in height between opposite saxboards at
the measuring point translates into a 7 - 9mm height error at the gate.
So rig the boat for all at the same height of work, leave it sitting on
the trestles, turn all the gates/oarlocks inwards, stand well ahead of
the bow & look straight along it at gates level - do they look to be in
line, all on exactly the same level? If not, the problem is with how
you're measuring, which may well be down to your assuming that irregular
saxboard lines are straight.

Remember that boatbuilders are as human as you are. So never assume,
always check - especially when seeking a perfect datum for rig height
measurements.

When we build riggers for boats we have not ourselves measured, the
information over which we are most careful to get our clients to take no
chances is the sax bevel angle (see above). Sometimes we receive
excellently prepared specifications, then see that instead of faxing or
emailing the scribed lines that we advise people to make (see:
https://www.carldouglas.co.uk/riggerform.php?id=0&source=freight
&
https://www.carldouglas.co.uk/images/bevels.gif
),
they've assumed the builder had worked to exact integer angles. So they
get out their grotty school protractor, see it looks like they've
scribed an angle a bit under 75 degrees & tell us it was a dead 75
degrees. That rings alarm bells: when we press for the original data, &
they send us the sheet or image with all the scribed lines on it - lo,
their 75 degree angle turns out to be 73.3 degrees! Had we built that
rigger to their original figure, it'd have ended up about 17mm lower
than intended. That's an expensive error, especially if you're half a
world away from us. So we _always_ query anything in rigger
specifications which looks too good, and anything that looks even
slightly wrong.

Being that extra bit careful & trusting to nothing ensures that everyone
is happy with the result. The same with rigging your boat.

Cheers -
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: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)


22 Dec 2006 04:39:01
donal.casey@gmail.com
Re: Adjusting the rigging for a men's club 8 - advice needed.

Personally after going through the rigmarole of spanning and heighting
a starting point accurately by tape on eights quads and Octs I find a
useful check is to (first without the gates on and then with the gates
on) sight down the boat to make sure that everything is straight and
true.

Only then to start making adjustments for height of rower and any other
individual seat requirements.

Also as I blame my bad back on "Aylogs" and a finished boat that they
produced ( a one off ????????????) I would recommend that the very
first job before measuring riggers is to put a plumb line from bow to
stern and check all the slides are equidisant from dead centre.

Then to make sure the boat is totally level and check that all the
slide beds are true in both planes. The offending boat had both unlevel
slide decks and the slides were going at an angle across the boat. We
had the boat brand new and it turned up in time for Gent...had to rig
quickly and race without being aware of the cockup and my back went
pop!

Donal



Carl wrote:
> Teaplant wrote:
> > you might want to consider the different geometries of your oarsmen...
> > an important factor is their 'seated height'... a 6ft tall athlete may
> > have long legs and a short back (a giraffe) or short legs and a long
> > back (scooby doo!). these people would need very different rigs for
> > comfort and efficiency.
> > I would do exactly what you are doing - check it over and square it all
> > up first. Then trial and error to fine tune. Key landmarks are
> > hand/elbow/shoulder position at the finish (check with all 8 at
> > backstops buried and square) and hands clear of the thighs through the
> > recovery (check with four holding at a time and eyeball it). if
> > everything *looks* ok and *feels* ok to coach and rowers then it is
> > probably ok.
> > So long as the boat is not too floppy and the pins are all upright with
> > TDs correct (can of worms), you will then be pretty close to optimum
> > for your crew. Beyond that you are better off training harder than
> > getting too scientific .
> > On a related note, I have often noticed my stern pairs prefer a little
> > more height than the rest, although on the paddle this seems
> > over-generous. At pace it comes right... is this the boat trimming
> > differently at speed?
> >
> > teaplant.
> >
>
> The points made so far are well made & most relevant. A further
> important consideration is: how are you measuring those heights?
>
> If, like almost every coach, you're using a height stick, do you really
> know that the tops of the saxboards (US = gunwales) are straight & level
> along the boat? We rigged up a brand new Boat Race eight &, during
> measurement, I saw that one saxboard had a marked droop in the vertical
> plane. The effect was that, if all riggers were actually at the same
> height, when measured by height stick they'd seem to vary along the
> length of the boat by over 1cm between the ends of the boat & the
> middle. That meant #5 on bowside seemed >1cm low & #4 on strokeside
> seemed 1cm high. I measured all sax bevel angles with a digital level &
> pointed out the sax droop to the boatman, asking what the club'd do
> about it. Their decision was that we should make the riggers & they'd
> live with the problem - even though that problem would be with that boat
> wherever it went.
>
> On an eight, a 5mm differential in height between opposite saxboards at
> the measuring point translates into a 7 - 9mm height error at the gate.
> So rig the boat for all at the same height of work, leave it sitting on
> the trestles, turn all the gates/oarlocks inwards, stand well ahead of
> the bow & look straight along it at gates level - do they look to be in
> line, all on exactly the same level? If not, the problem is with how
> you're measuring, which may well be down to your assuming that irregular
> saxboard lines are straight.
>
> Remember that boatbuilders are as human as you are. So never assume,
> always check - especially when seeking a perfect datum for rig height
> measurements.
>
> When we build riggers for boats we have not ourselves measured, the
> information over which we are most careful to get our clients to take no
> chances is the sax bevel angle (see above). Sometimes we receive
> excellently prepared specifications, then see that instead of faxing or
> emailing the scribed lines that we advise people to make (see:
> https://www.carldouglas.co.uk/riggerform.php?id=0&source=freight
> &
> https://www.carldouglas.co.uk/images/bevels.gif
> ),
> they've assumed the builder had worked to exact integer angles. So they
> get out their grotty school protractor, see it looks like they've
> scribed an angle a bit under 75 degrees & tell us it was a dead 75
> degrees. That rings alarm bells: when we press for the original data, &
> they send us the sheet or image with all the scribed lines on it - lo,
> their 75 degree angle turns out to be 73.3 degrees! Had we built that
> rigger to their original figure, it'd have ended up about 17mm lower
> than intended. That's an expensive error, especially if you're half a
> world away from us. So we _always_ query anything in rigger
> specifications which looks too good, and anything that looks even
> slightly wrong.
>
> Being that extra bit careful & trusting to nothing ensures that everyone
> is happy with the result. The same with rigging your boat.
>
> Cheers -
> 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: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
> URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)



22 Dec 2006 04:55:39
Re: Adjusting the rigging for a men's club 8 - advice needed.



On Dec 22, 12:39 pm, "donal.ca...@gmail.com" <donal.ca...@gmail.com >
wrote:
> Personally after going through the rigmarole of spanning and heighting
> a starting point accurately by tape on eights quads and Octs I find a
> useful check is to (first without the gates on and then with the gates
> on) sight down the boat to make sure that everything is straight and
> true.
>
> Only then to start making adjustments for height of rower and any other
> individual seat requirements.
>
> Also as I blame my bad back on "Aylogs" and a finished boat that they
> produced ( a one off ????????????) I would recommend that the very
> first job before measuring riggers is to put a plumb line from bow to
> stern and check all the slides are equidisant from dead centre.
>
> Then to make sure the boat is totally level and check that all the
> slide beds are true in both planes. The offending boat had both unlevel
> slide decks and the slides were going at an angle across the boat. We
> had the boat brand new and it turned up in time for Gent...had to rig
> quickly and race without being aware of the cockup and my back went
> pop!
>
> Donal
>
>
>
> Carl wrote:
> > Teaplant wrote:
> > > you might want to consider the different geometries of your oarsmen...
> > > an important factor is their 'seated height'... a 6ft tall athlete may
> > > have long legs and a short back (a giraffe) or short legs and a long
> > > back (scooby doo!). these people would need very different rigs for
> > > comfort and efficiency.
> > > I would do exactly what you are doing - check it over and square it all
> > > up first. Then trial and error to fine tune. Key landmarks are
> > > hand/elbow/shoulder position at the finish (check with all 8 at
> > > backstops buried and square) and hands clear of the thighs through the
> > > recovery (check with four holding at a time and eyeball it). if
> > > everything *looks* ok and *feels* ok to coach and rowers then it is
> > > probably ok.
> > > So long as the boat is not too floppy and the pins are all upright with
> > > TDs correct (can of worms), you will then be pretty close to optimum
> > > for your crew. Beyond that you are better off training harder than
> > > getting too scientific .
> > > On a related note, I have often noticed my stern pairs prefer a little
> > > more height than the rest, although on the paddle this seems
> > > over-generous. At pace it comes right... is this the boat trimming
> > > differently at speed?
>
> > > teaplant.
>
> > The points made so far are well made & most relevant. A further
> > important consideration is: how are you measuring those heights?
>
> > If, like almost every coach, you're using a height stick, do you really
> > know that the tops of the saxboards (US = gunwales) are straight & level
> > along the boat? We rigged up a brand new Boat Race eight &, during
> > measurement, I saw that one saxboard had a marked droop in the vertical
> > plane. The effect was that, if all riggers were actually at the same
> > height, when measured by height stick they'd seem to vary along the
> > length of the boat by over 1cm between the ends of the boat & the
> > middle. That meant #5 on bowside seemed >1cm low & #4 on strokeside
> > seemed 1cm high. I measured all sax bevel angles with a digital level &
> > pointed out the sax droop to the boatman, asking what the club'd do
> > about it. Their decision was that we should make the riggers & they'd
> > live with the problem - even though that problem would be with that boat
> > wherever it went.
>
> > On an eight, a 5mm differential in height between opposite saxboards at
> > the measuring point translates into a 7 - 9mm height error at the gate.
> > So rig the boat for all at the same height of work, leave it sitting on
> > the trestles, turn all the gates/oarlocks inwards, stand well ahead of
> > the bow & look straight along it at gates level - do they look to be in
> > line, all on exactly the same level? If not, the problem is with how
> > you're measuring, which may well be down to your assuming that irregular
> > saxboard lines are straight.
>
> > Remember that boatbuilders are as human as you are. So never assume,
> > always check - especially when seeking a perfect datum for rig height
> > measurements.
>
> > When we build riggers for boats we have not ourselves measured, the
> > information over which we are most careful to get our clients to take no
> > chances is the sax bevel angle (see above). Sometimes we receive
> > excellently prepared specifications, then see that instead of faxing or
> > emailing the scribed lines that we advise people to make (see:
> > https://www.carldouglas.co.uk/riggerform.php?id=0&source=freight
> > &
> > https://www.carldouglas.co.uk/images/bevels.gif
> > ),
> > they've assumed the builder had worked to exact integer angles. So they
> > get out their grotty school protractor, see it looks like they've
> > scribed an angle a bit under 75 degrees & tell us it was a dead 75
> > degrees. That rings alarm bells: when we press for the original data, &
> > they send us the sheet or image with all the scribed lines on it - lo,
> > their 75 degree angle turns out to be 73.3 degrees! Had we built that
> > rigger to their original figure, it'd have ended up about 17mm lower
> > than intended. That's an expensive error, especially if you're half a
> > world away from us. So we _always_ query anything in rigger
> > specifications which looks too good, and anything that looks even
> > slightly wrong.
>
> > Being that extra bit careful & trusting to nothing ensures that everyone
> > is happy with the result. The same with rigging your boat.
>
> > Cheers -
> > 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: c...@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
> > URLs: www.carldouglas.co.uk(boats) &www.aerowing.co.uk(riggers)- Hide quoted text -- Show quoted text -

Are you sure it isn't the rowers' technique which is causing problems?

Just a thought....

Caroline



22 Dec 2006 05:44:24
Jonny
Re: Adjusting the rigging for a men's club 8 - advice needed.



On Dec 22, 11:55 pm, carolin...@aol.com wrote:
> On Dec 22, 12:39 pm, "donal.ca...@gmail.com" <donal.ca...@gmail.com>
> wrote:
>
>
>
> > Personally after going through the rigmarole of spanning and heighting
> > a starting point accurately by tape on eights quads and Octs I find a
> > useful check is to (first without the gates on and then with the gates
> > on) sight down the boat to make sure that everything is straight and
> > true.
>
> > Only then to start making adjustments for height of rower and any other
> > individual seat requirements.
>
> > Also as I blame my bad back on "Aylogs" and a finished boat that they
> > produced ( a one off ????????????) I would recommend that the very
> > first job before measuring riggers is to put a plumb line from bow to
> > stern and check all the slides are equidisant from dead centre.
>
> > Then to make sure the boat is totally level and check that all the
> > slide beds are true in both planes. The offending boat had both unlevel
> > slide decks and the slides were going at an angle across the boat. We
> > had the boat brand new and it turned up in time for Gent...had to rig
> > quickly and race without being aware of the cockup and my back went
> > pop!
>
> > Donal
>
> > Carl wrote:
> > > Teaplant wrote:
> > > > you might want to consider the different geometries of your oarsmen...
> > > > an important factor is their 'seated height'... a 6ft tall athlete may
> > > > have long legs and a short back (a giraffe) or short legs and a long
> > > > back (scooby doo!). these people would need very different rigs for
> > > > comfort and efficiency.
> > > > I would do exactly what you are doing - check it over and square it all
> > > > up first. Then trial and error to fine tune. Key landmarks are
> > > > hand/elbow/shoulder position at the finish (check with all 8 at
> > > > backstops buried and square) and hands clear of the thighs through the
> > > > recovery (check with four holding at a time and eyeball it). if
> > > > everything *looks* ok and *feels* ok to coach and rowers then it is
> > > > probably ok.
> > > > So long as the boat is not too floppy and the pins are all upright with
> > > > TDs correct (can of worms), you will then be pretty close to optimum
> > > > for your crew. Beyond that you are better off training harder than
> > > > getting too scientific .
> > > > On a related note, I have often noticed my stern pairs prefer a little
> > > > more height than the rest, although on the paddle this seems
> > > > over-generous. At pace it comes right... is this the boat trimming
> > > > differently at speed?
>
> > > > teaplant.
>
> > > The points made so far are well made & most relevant. A further
> > > important consideration is: how are you measuring those heights?
>
> > > If, like almost every coach, you're using a height stick, do you really
> > > know that the tops of the saxboards (US = gunwales) are straight & level
> > > along the boat? We rigged up a brand new Boat Race eight &, during
> > > measurement, I saw that one saxboard had a marked droop in the vertical
> > > plane. The effect was that, if all riggers were actually at the same
> > > height, when measured by height stick they'd seem to vary along the
> > > length of the boat by over 1cm between the ends of the boat & the
> > > middle. That meant #5 on bowside seemed >1cm low & #4 on strokeside
> > > seemed 1cm high. I measured all sax bevel angles with a digital level &
> > > pointed out the sax droop to the boatman, asking what the club'd do
> > > about it. Their decision was that we should make the riggers & they'd
> > > live with the problem - even though that problem would be with that boat
> > > wherever it went.
>
> > > On an eight, a 5mm differential in height between opposite saxboards at
> > > the measuring point translates into a 7 - 9mm height error at the gate.
> > > So rig the boat for all at the same height of work, leave it sitting on
> > > the trestles, turn all the gates/oarlocks inwards, stand well ahead of
> > > the bow & look straight along it at gates level - do they look to be in
> > > line, all on exactly the same level? If not, the problem is with how
> > > you're measuring, which may well be down to your assuming that irregular
> > > saxboard lines are straight.
>
> > > Remember that boatbuilders are as human as you are. So never assume,
> > > always check - especially when seeking a perfect datum for rig height
> > > measurements.
>
> > > When we build riggers for boats we have not ourselves measured, the
> > > information over which we are most careful to get our clients to take no
> > > chances is the sax bevel angle (see above). Sometimes we receive
> > > excellently prepared specifications, then see that instead of faxing or
> > > emailing the scribed lines that we advise people to make (see:
> > > https://www.carldouglas.co.uk/riggerform.php?id=0&source=freight
> > > &
> > > https://www.carldouglas.co.uk/images/bevels.gif
> > > ),
> > > they've assumed the builder had worked to exact integer angles. So they
> > > get out their grotty school protractor, see it looks like they've
> > > scribed an angle a bit under 75 degrees & tell us it was a dead 75
> > > degrees. That rings alarm bells: when we press for the original data, &
> > > they send us the sheet or image with all the scribed lines on it - lo,
> > > their 75 degree angle turns out to be 73.3 degrees! Had we built that
> > > rigger to their original figure, it'd have ended up about 17mm lower
> > > than intended. That's an expensive error, especially if you're half a
> > > world away from us. So we _always_ query anything in rigger
> > > specifications which looks too good, and anything that looks even
> > > slightly wrong.
>
> > > Being that extra bit careful & trusting to nothing ensures that everyone
> > > is happy with the result. The same with rigging your boat.
>
> > > Cheers -
> > > 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: c...@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
> > > URLs: www.carldouglas.co.uk(boats) &www.aerowing.co.uk(riggers)-Hide quoted text -- Show quoted text -Are you sure it isn't the rowers' technique which is causing problems?
>
> Just a thought....
>
> Caroline

I've seen plenty of bent riggers over the years that throw things out
and there was this one boat that had a slight twist in it that meant
that stroke seat was always moaning about it being too low!



22 Dec 2006 13:45:08
David Jillings
Re: Adjusting the rigging for a men's club 8 - advice needed.

No. It is never the rower's technique that is at fault. It is always the
boat/rig. That's one of the first things I learned and I thought everybody
knew that!

David.
<carolinetu@aol.com > wrote in message
news:1166792139.683710.222540@i12g2000cwa.googlegroups.com...
>
> Are you sure it isn't the rowers' technique which is causing problems?
>
> Just a thought....
>
> Caroline

>
> On Dec 22, 12:39 pm, "donal.ca...@gmail.com" <donal.ca...@gmail.com>
> wrote:
>> Personally after going through the rigmarole of spanning and heighting
>> a starting point accurately by tape on eights quads and Octs I find a
>> useful check is to (first without the gates on and then with the gates
>> on) sight down the boat to make sure that everything is straight and
>> true.
>>
>> Only then to start making adjustments for height of rower and any other
>> individual seat requirements.
>>
>> Also as I blame my bad back on "Aylogs" and a finished boat that they
>> produced ( a one off ????????????) I would recommend that the very
>> first job before measuring riggers is to put a plumb line from bow to
>> stern and check all the slides are equidisant from dead centre.
>>
>> Then to make sure the boat is totally level and check that all the
>> slide beds are true in both planes. The offending boat had both unlevel
>> slide decks and the slides were going at an angle across the boat. We
>> had the boat brand new and it turned up in time for Gent...had to rig
>> quickly and race without being aware of the cockup and my back went
>> pop!
>>
>> Donal
>>
>>
>>
>> Carl wrote:
>> > Teaplant wrote:
>> > > you might want to consider the different geometries of your
>> > > oarsmen...
>> > > an important factor is their 'seated height'... a 6ft tall athlete
>> > > may
>> > > have long legs and a short back (a giraffe) or short legs and a long
>> > > back (scooby doo!). these people would need very different rigs for
>> > > comfort and efficiency.
>> > > I would do exactly what you are doing - check it over and square it
>> > > all
>> > > up first. Then trial and error to fine tune. Key landmarks are
>> > > hand/elbow/shoulder position at the finish (check with all 8 at
>> > > backstops buried and square) and hands clear of the thighs through
>> > > the
>> > > recovery (check with four holding at a time and eyeball it). if
>> > > everything *looks* ok and *feels* ok to coach and rowers then it is
>> > > probably ok.
>> > > So long as the boat is not too floppy and the pins are all upright
>> > > with
>> > > TDs correct (can of worms), you will then be pretty close to optimum
>> > > for your crew. Beyond that you are better off training harder than
>> > > getting too scientific .
>> > > On a related note, I have often noticed my stern pairs prefer a
>> > > little
>> > > more height than the rest, although on the paddle this seems
>> > > over-generous. At pace it comes right... is this the boat trimming
>> > > differently at speed?
>>
>> > > teaplant.
>>
>> > The points made so far are well made & most relevant. A further
>> > important consideration is: how are you measuring those heights?
>>
>> > If, like almost every coach, you're using a height stick, do you really
>> > know that the tops of the saxboards (US = gunwales) are straight &
>> > level
>> > along the boat? We rigged up a brand new Boat Race eight &, during
>> > measurement, I saw that one saxboard had a marked droop in the vertical
>> > plane. The effect was that, if all riggers were actually at the same
>> > height, when measured by height stick they'd seem to vary along the
>> > length of the boat by over 1cm between the ends of the boat & the
>> > middle. That meant #5 on bowside seemed >1cm low & #4 on strokeside
>> > seemed 1cm high. I measured all sax bevel angles with a digital level
>> > &
>> > pointed out the sax droop to the boatman, asking what the club'd do
>> > about it. Their decision was that we should make the riggers & they'd
>> > live with the problem - even though that problem would be with that
>> > boat
>> > wherever it went.
>>
>> > On an eight, a 5mm differential in height between opposite saxboards at
>> > the measuring point translates into a 7 - 9mm height error at the gate.
>> > So rig the boat for all at the same height of work, leave it sitting on
>> > the trestles, turn all the gates/oarlocks inwards, stand well ahead of
>> > the bow & look straight along it at gates level - do they look to be in
>> > line, all on exactly the same level? If not, the problem is with how
>> > you're measuring, which may well be down to your assuming that
>> > irregular
>> > saxboard lines are straight.
>>
>> > Remember that boatbuilders are as human as you are. So never assume,
>> > always check - especially when seeking a perfect datum for rig height
>> > measurements.
>>
>> > When we build riggers for boats we have not ourselves measured, the
>> > information over which we are most careful to get our clients to take
>> > no
>> > chances is the sax bevel angle (see above). Sometimes we receive
>> > excellently prepared specifications, then see that instead of faxing or
>> > emailing the scribed lines that we advise people to make (see:
>> > https://www.carldouglas.co.uk/riggerform.php?id=0&source=freight
>> > &
>> > https://www.carldouglas.co.uk/images/bevels.gif
>> > ),
>> > they've assumed the builder had worked to exact integer angles. So
>> > they
>> > get out their grotty school protractor, see it looks like they've
>> > scribed an angle a bit under 75 degrees & tell us it was a dead 75
>> > degrees. That rings alarm bells: when we press for the original data,
>> > &
>> > they send us the sheet or image with all the scribed lines on it - lo,
>> > their 75 degree angle turns out to be 73.3 degrees! Had we built that
>> > rigger to their original figure, it'd have ended up about 17mm lower
>> > than intended. That's an expensive error, especially if you're half a
>> > world away from us. So we _always_ query anything in rigger
>> > specifications which looks too good, and anything that looks even
>> > slightly wrong.
>>
>> > Being that extra bit careful & trusting to nothing ensures that
>> > everyone
>> > is happy with the result. The same with rigging your boat.
>>
>> > Cheers -
>> > 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: c...@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
>> > URLs: www.carldouglas.co.uk(boats) &www.aerowing.co.uk(riggers)- Hide
>> > quoted text -- Show quoted text -
>
> Are you sure it isn't the rowers' technique which is causing problems?
>
> Just a thought....
>
> Caroline
>




22 Dec 2006 10:58:00
IPS
Re: Adjusting the rigging for a men's club 8 - advice needed.

Carl,
Are not most height sticks used to measure the distance from the sill
to the seat? For this purpose at least, it shouldn't matter that the
gunwales are off.

17cm would seem to be low for guys in an eight. The junior girls I
coach are set between 16.5cm and 17.5cm, on average.

Ian


Carl wrote:
>
> The points made so far are well made & most relevant. A further
> important consideration is: how are you measuring those heights?
>
> If, like almost every coach, you're using a height stick, do you really
> know that the tops of the saxboards (US = gunwales) are straight & level
> along the boat? We rigged up a brand new Boat Race eight &, during
> measurement, I saw that one saxboard had a marked droop in the vertical
> plane. The effect was that, if all riggers were actually at the same
> height, when measured by height stick they'd seem to vary along the
> length of the boat by over 1cm between the ends of the boat & the
> middle. That meant #5 on bowside seemed >1cm low & #4 on strokeside
> seemed 1cm high. I measured all sax bevel angles with a digital level &
> pointed out the sax droop to the boatman, asking what the club'd do
> about it. Their decision was that we should make the riggers & they'd
> live with the problem - even though that problem would be with that boat
> wherever it went.
>
> On an eight, a 5mm differential in height between opposite saxboards at
> the measuring point translates into a 7 - 9mm height error at the gate.
> So rig the boat for all at the same height of work, leave it sitting on
> the trestles, turn all the gates/oarlocks inwards, stand well ahead of
> the bow & look straight along it at gates level - do they look to be in
> line, all on exactly the same level? If not, the problem is with how
> you're measuring, which may well be down to your assuming that irregular
> saxboard lines are straight.
>
> Remember that boatbuilders are as human as you are. So never assume,
> always check - especially when seeking a perfect datum for rig height
> measurements.
>
> When we build riggers for boats we have not ourselves measured, the
> information over which we are most careful to get our clients to take no
> chances is the sax bevel angle (see above). Sometimes we receive
> excellently prepared specifications, then see that instead of faxing or
> emailing the scribed lines that we advise people to make (see:
> https://www.carldouglas.co.uk/riggerform.php?id=0&source=freight
> &
> https://www.carldouglas.co.uk/images/bevels.gif
> ),
> they've assumed the builder had worked to exact integer angles. So they
> get out their grotty school protractor, see it looks like they've
> scribed an angle a bit under 75 degrees & tell us it was a dead 75
> degrees. That rings alarm bells: when we press for the original data, &
> they send us the sheet or image with all the scribed lines on it - lo,
> their 75 degree angle turns out to be 73.3 degrees! Had we built that
> rigger to their original figure, it'd have ended up about 17mm lower
> than intended. That's an expensive error, especially if you're half a
> world away from us. So we _always_ query anything in rigger
> specifications which looks too good, and anything that looks even
> slightly wrong.
>
> Being that extra bit careful & trusting to nothing ensures that everyone
> is happy with the result. The same with rigging your boat.
>
> Cheers -
> 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: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
> URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)



22 Dec 2006 19:15:33
mpruscoe
Re: Adjusting the rigging for a men's club 8 - advice needed.

IPS wrote:
> Carl,
> Are not most height sticks used to measure the distance from the sill
> to the seat? For this purpose at least, it shouldn't matter that the
> gunwales are off.
>

Yes they are, but the parallelogram-style sticks are rested across the
gunwales in order to make that measurement so any difference in the
height of the gunwales is magnified out at the outboard end of the
rigger. If you have the style of height stick that stands in the slides,
then it's not a problem, but you than have to check whether all the
decks are level with respect to each other.


22 Dec 2006 11:31:37
IPS
Re: Adjusting the rigging for a men's club 8 - advice needed.

That makes sense. Thanks.


mpruscoe wrote:
> IPS wrote:
> > Carl,
> > Are not most height sticks used to measure the distance from the sill
> > to the seat? For this purpose at least, it shouldn't matter that the
> > gunwales are off.
> >
>
> Yes they are, but the parallelogram-style sticks are rested across the
> gunwales in order to make that measurement so any difference in the
> height of the gunwales is magnified out at the outboard end of the
> rigger. If you have the style of height stick that stands in the slides,
> then it's not a problem, but you than have to check whether all the
> decks are level with respect to each other.



22 Dec 2006 12:21:50
Anne Rogers
Re: Adjusting the rigging for a men's club 8 - advice needed.


> No. It is never the rower's technique that is at fault. It is always the
> boat/rig. That's one of the first things I learned and I thought
> everybody knew that!

though on the other hand, there are so many different things that can go
wrong with equipment, it's always worth checking, I remember one rower who
always got much much worse blisters than everyone else, we checked her
technique and there was nothing that would cause blisters and assumed it was
just her hands and skin. The we swapped seats and the rower in her old seat
also got major blisters, still took a while to figure it out, eventually it
turned out that a hollow blade had somehow got filled with water, of course
the coaches/cox never picked up a single blade so never noticed, and the
rowers were fairly inexperienced and also never noticed.

Anne




22 Dec 2006 12:23:27
Anne Rogers
Re: Adjusting the rigging for a men's club 8 - advice needed.

I presume you've checked both the height of the feet and the position of the
feet, I've seen it too many times, you assume a rower knows how to set these
things up, you try to coach them on a fault, then you spot that the feet are
wrong, you switch that and there is a big improvement.

Cheers

Anne




22 Dec 2006 15:19:05
Teaplant
Re: Adjusting the rigging for a men's club 8 - advice needed.

it can't be stressed enough that you eyeball the alignment of the
swivels once an eight is rigged - this only takes a couple of seconds
and picks up an enormous range of rigging faults.

it is not unheard of for crews at regattas to carelessly bolt the wrong
rigger on at the wrong seat (swapping 3 and 5 seems to be a particular
favourite for some reason!) and not even notice the enormous tension
this puts the backstays under! An (ex) colleague even once starboard
rigged an entire eight just by bolting the riggers in their new places,
otherwise unadjusted! Simply turning the swivels outwards and looking
along your eight to see if they align - any problems will be
immediately apparent. It will also help to pick up warps and bends in
the boat. Pairs and fours, btw, (or 1x and 2x), and you are on your
own (just ring Carl).

Ultimately, for those of us with old, battered boats and rig, you have
to 'rig-out' these twists, bends and warps with just a 10/13 mm spanner
and a bit of scaffolding pipe for fine tuning. All that actually
matters is the geometry of the swivel relative to the slide-beds and
shoes. It won't matter if the riggers don't line up so long as the pins
are vertical (both axes) and the TD/heights are where you want them.

For the original question, I had presumed that the final part of the
rigging procedure included an alignment check of the swivels along the
boat. If so, I would still suspect that the athletes themselves
(unusual shapes thereof) are the main issues, compounded by the fact
that stern pairs (the thoroughbreds) are more sensitive to heights than
the middle-four (the shire-horses). Bow pairs never seem to care or
notice (the jackasses).

teaplant.

ps Specifically, your seven-man will think he's a great rower (because
you put him in the stern pair), he will be taller than your stroke-man
(where else can you hide a dwarf?), he won't have a great deal else to
think about other than his own bladework (there's no one else's blade
to look at and he isn't setting the rhythm), he feels he is crew
captain (because the cox can hear him and stroke's busy) and if he
struggles to get his blade off the water on the recovery it must be the
rigging (because "its not my job to keep the boat balanced you f*cking
donkeys back there!"). I would swap him with your bow-man for an
outing or two and say things like 'hmmm, you both seem to have enough
height in this lineup' or 'lets run with this for a month or two' and
he'll soon shut up moaning when he gets back to 'his' seat.



23 Dec 2006 13:30:56
Carl
Re: Adjusting the rigging for a men's club 8 - advice needed.

Teaplant wrote:
> it can't be stressed enough that you eyeball the alignment of the
> swivels once an eight is rigged - this only takes a couple of seconds
> and picks up an enormous range of rigging faults.
>
> it is not unheard of for crews at regattas to carelessly bolt the wrong
> rigger on at the wrong seat (swapping 3 and 5 seems to be a particular
> favourite for some reason!) and not even notice the enormous tension
> this puts the backstays under! An (ex) colleague even once starboard
> rigged an entire eight just by bolting the riggers in their new places,
> otherwise unadjusted! Simply turning the swivels outwards and looking
> along your eight to see if they align - any problems will be
> immediately apparent. It will also help to pick up warps and bends in
> the boat. Pairs and fours, btw, (or 1x and 2x), and you are on your
> own (just ring Carl).
>
> Ultimately, for those of us with old, battered boats and rig, you have
> to 'rig-out' these twists, bends and warps with just a 10/13 mm spanner
> and a bit of scaffolding pipe for fine tuning.

Arrrrggghhhh!

Only crap riggers use scaffold poles. Intelligent riggers use AxioR.

(According to the dictionary, any dictionary, among its other meanings a
rigger may be a device extending from a boat to support the thole-pin &
oarlock, or someone who uses a scaffold pole ;) )

Any rigger you can "adjust" with a scaffold pole is a rigger that a) you
will weaken & damage by so doing & b) which will progressively re-adjust
itself in use.

All that actually
> matters is the geometry of the swivel relative to the slide-beds and
> shoes. It won't matter if the riggers don't line up so long as the pins
> are vertical (both axes) and the TD/heights are where you want them.
>
> For the original question, I had presumed that the final part of the
> rigging procedure included an alignment check of the swivels along the
> boat. If so, I would still suspect that the athletes themselves
> (unusual shapes thereof) are the main issues, compounded by the fact
> that stern pairs (the thoroughbreds) are more sensitive to heights than
> the middle-four (the shire-horses). Bow pairs never seem to care or
> notice (the jackasses).

What matter most of all in pitching terms is that there are:
1. The same pitches _on the pins_ in all positions
2. The same pitches on the blades, ditto.

Pin pitch is not interchangable with oarlock pulling face pitch. You
cannot satisfactorily correct for errors in pin pitch by changing the
inserts in the oarlock - this may make pitch correct at one point in the
stroke, but it will go increasingly wrong as you move away from that point.

Oarlock adjustment serves only these 2 purposes:
1. If your oar is mis-pitched (i.e. sleeve/blade misalignment) it allows
this to be corrected (to within +/- 0.25 degrees)
2. It allows you to have uniformly more (or less) pitch at all points of
the stroke

For anything from a 2x or 2- upwards, you can confirm that lateral
pitches on one side are equal by removing the oarlocks (unless they have
identical pitch settings) & looking along the riggers of each side to
compare their alignments. The human eye is more sensitive to pitch
differences than most pitch gauges.

For any sculling boat you can confirm that stern pitches are equal by
sighting straight across the boat, ditto.


>
> teaplant.
>
> ps Specifically, your seven-man will think he's a great rower (because
> you put him in the stern pair), he will be taller than your stroke-man
> (where else can you hide a dwarf?), he won't have a great deal else to
> think about other than his own bladework (there's no one else's blade
> to look at and he isn't setting the rhythm), he feels he is crew
> captain (because the cox can hear him and stroke's busy) and if he
> struggles to get his blade off the water on the recovery it must be the
> rigging (because "its not my job to keep the boat balanced you f*cking
> donkeys back there!"). I would swap him with your bow-man for an
> outing or two and say things like 'hmmm, you both seem to have enough
> height in this lineup' or 'lets run with this for a month or two' and
> he'll soon shut up moaning when he gets back to 'his' seat.
>

Who said rowing had anything to do with psychology, except that we must
all be nuts that do it?

Cheers -
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: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)


29 Dec 2006 03:27:42
Pete W
Re: Adjusting the rigging for a men's club 8 - advice needed.


Carl wrote:
>
> Arrrrggghhhh!
>
> Only crap riggers use scaffold poles. Intelligent riggers use AxioR.
>

hmm, I've seen Billy Mason use a scaffold pole @ IC... he may be a
"crap rigger" (I assume this refers to one who rigs and not the bit of
metal sticking out the side of the boat;-) ) but his results speak for
themselves!

Anyway, Thanks for all the advice, this has been the first chance I've
had to check the newsgroup since i originally posted.

Cheers,
Pete



29 Dec 2006 13:33:57
John Mulholland
Re: Adjusting the rigging for a men's club 8 - advice needed.

"Pete W" <vestacoach@googlemail.com > wrote in message
news:1167391662.082033.262970@h40g2000cwb.googlegroups.com...
>
> Carl wrote:
>>
>> Arrrrggghhhh!
>>
>> Only crap riggers use scaffold poles. Intelligent riggers use AxioR.
>>
>
> hmm, I've seen Billy Mason use a scaffold pole @ IC... he may be a
> "crap rigger" (I assume this refers to one who rigs and not the bit of
> metal sticking out the side of the boat;-) ) but his results speak
> themselves!
>
> Anyway, Thanks for all the advice, this has been the first chance I've
> had to check the newsgroup since i originally posted.
>
> Cheers,
> Pete
>

I think Carl was referring to the inanimate riggers attached to the side of
your boat, not to Billy Mason, or any other person working as a rigger!

--
John Mulholland




03 Jan 2007 18:40:58
Walter Martindale
Re: Adjusting the rigging for a men's club 8 - advice needed.

Ok, then... to check if the gunwales/sills and the deck/slides are
parallel (one hopes with the waterline also) - take two spirit levels,
one shorter one across the slides at the same fore-aft position (best if
it's on the perpendicular on which the pin sits, too, so that it's a)
perpendicular to the boat and b) where you're going to measure the
height), and one above that that spans the gunwales. if they're
parallel (i.e., both are level) then you're off to the races for
measuring up to the gate and down to the seat from the gunwale. If
they're not parallel, then you need the empacher-style height tool that
sits in the tracks.

The bit about checking the ribs/knees for their integrity is also valid,
if your boat has such beasts.
Then - my preference for rigging is to have the pins all "vertical" or
perpendicular to the mean surface of the water when the boat is level.
From there, I check that the pitch plugs/wedges (whatever) in the gates
are all the same. Then it's a good idea to check that the pitches on
all the blades are the same - preferably zero (according to the
manufacturer's definition of zero, and these differ from mfr to mfr.)
If all that's within what you think is right, then it's probably the
rower and his/her movements that is messing up. It doesn't really
matter who built the riggers (sorry Carl) if they're strong, light,
stiff, robust, and able to hold their adjustment under load if properly
tightened. Some boat builders have adjustable pins (Carl's, for
example) and these are quite handy. Some have doohickeys that need
bending or wedging so that you get your pin vertical, but once there if
the rigger is well enough built, it shouldn't have taken much adjustment
to get the pin vertical, and it should be pretty robust - but we've all
run into some pretty shoddy equipment, haven't we....

If you're using a "pitching gauge" or "pitchmeter", are you making sure
you're reading it facing the same way each time so that you're not
zero-ing on one slope, and reading it on the reverse? That can cause
problems.

The bit about blades having the same pitch is important - for a few
years (so the C2 guys have told me) there was a problem where the shafts
would turn a little after assembly as the resins in the shafts continued
to cure - since all the shafts were built on the same mandrel with the
same direction of the winding on of the carbon, the twisting of the
shafts was in the same direction - if I remember correctly, most sets
I've adjusted had negative pitch on port (stroke side) and positive
pitch on starboard (bow side). Checking this with appropriately placed
spirit levels (careful - it's fussy) and then scraping down the "high"
side of the wear plate on the sleeve will generally fix the problem
until you can get C2 to replace/reposition the sleeves.

Whew. Hope this helps
Walter

Pete W wrote:
> Hi,
>
> I measured an eight that is used by our club's first 8 last weekend and
> i find i need some advice.
>
> i can measure a boat well enough and to within the recommended in
> ARA/Fisa publications but much beyond that i can't do.
>
> when i asked the lads to get the shell off the rack and measured it i
> found the 7 & 4 seats very high (20.2 cm) and the rest of the boat
> round about 19cm. i thught this was too high and bought it all down to
> 17 cm.
>
> after the 1st outing it was obvious this was too low for the 7 & 4 men
> and we re-adjusted the heights to 18cm after the 1st outing. this was
> fine for the 4 man but after the 2nd outing we took the height as far
> we could for him - back to 20cm. And he still looks like he rowing too
> low.
>
> the plated weight for the shell is 95kgs and the average weight of the
> crew is 88.9 kgs.
>
> what worries me is there is a flaw in the shell - could it have
> twisted?
> or is there somethign i am doing wrong? (more than possible)
>
> any ideas i can investigate when i am next at the club would be
> gratefully received!
>
> Cheers,
> Pete
>


15 Jan 2007 05:00:15
PeteC
Re: Adjusting the rigging for a men's club 8 - advice needed.

Does anyone know where one can buy the above-mentioned empacher-style
height tool that sits in the tracks? Been looking for one for ages.



16 Jan 2007 12:23:51
Carl
Re: Adjusting the rigging for a men's club 8 - advice needed.

PeteC wrote:
> Does anyone know where one can buy the above-mentioned empacher-style
> height tool that sits in the tracks? Been looking for one for ages.
>

Some details regarding height measurement, which Walter & I have made
before but which, from reports I receive, seem to need repeating:

1. Measurement accuracy:
This is less the product of clever tooling & more the outcome of
meticulous practice. Clever tools in well-tutored hands will produce
excellent results but, unless you know what can go wrong & what to guard
against, they may convince the unwary that wrong is right. It is a good
rule that, if you can't get a good result with the most basic kit, you
are not yet ready to use the clever stuff. Thus a device which sits in
the tracks can be good, but only if you already know that the tracks are
level with each other & not sprung up from the deck, that you have
properly located the legs within the tracks, that those legs are exactly
parallel with each other, & that you are measuring perpendicularly
across the boat.

2. Error amplification:
Your tracks may be from 165mm (single) to 300mm (eight) apart,
centre-centre, whereas your pins are between 1580mm (single) & 1760mm
(pair) apart, measured across the boat, so any error in levels of tracks
across the boat, or registration of height gauge in the tracks, will
tend to amplify. Thus a 1mm error between tracks or gauge location in
tracks, due e.g. to one track being slightly sprung away from the deck
or having some dirt beneath it, may amplify into >10mm across the boat.

3. Manufacturing tolerances:
There may be small variations in slide bed & saxboard/gunwale top edge
alignment, as previously discussed. In some crew shells, even from big
name manufacturers, it is not absolutely guaranteed that the tops of the
saxboards/gunwales will be either straight or level. This does not mean
the boat is twisted but does mean you should not absolutely rely on
their accuracy unless you have checked it. A simple check with a spirit
level - both across the tops of the tracks & across the sax tops - will
tell you, provided you can properly read the level (surprisingly many
don't take enough care!). Use a short level & 2 visibly straight bars,
which have been checked for straightness by sighting along them, for
these measurements, with the boat supported in trestles & rigidly
chocked by sticks to the ground to prevent wobbling. And please
understand that the typical angular range between the bubble just
touching one hairline & it just touching the other hairline is 1 degree,
or ~1 in 57, which can cause an error in relative oarlock heights of ~3cm!

4. Apply other means to check your result:
If you think you have done everything right on any boat with more than 2
riggers, there is still one final test to perform. Having rigged
everyone to the same height, swing all oarlocks inwards and squat a good
distance ahead of the boat. Then look straight through/past every
oarlock on one side, then on the other, then on both: are they all in
perfect alignment? If not, you got it wrong & need to go back & find
out why.

5. Beware human deformity!:
If rigging a single, remember that we are not normally symmetrical.
This is a problem which I find is completely ignored, yet it may
completely blight a promising sculling career. One buttock may be
larger than the other, bone structure may be more pronounced on one
side, you may have slight lateral spinal curvature, etc. So it is
possible to rig a single (& other boats) seemingly perfectly yet still
find you can't get one blade off the water - because the asymmetry of
your contact with the seat forces the boat to tilt if you sit up
straight. The only satisfactory way to resolve this is to tilt the
seat, raising the side of it on which the rigger seems in use to be too
high, either by shimming between one side of the seat & the
undercarriage, or by shimming under that slide track. And you would be
amazed how much difference even a 1mm shim can make to how the boat sits
& how comfortable you are (see section 2, above, on error amplification).

HTH
Carl

PS PeterC, may I refer back to your comments in your 29 December posting?
Yes, I do think that bending riggers is a daft way to adjust pitch. I
accept that, if the riggers you have to use provide no other way of
adjustment, that's what you must do. But I do not accept that it is
sensible or rational to accept this as normal. Any rigger you can bend
is one that will itself bend under use & whose life is correspondingly
shortened. Each time you bend a rigger to re-pitch, you take a part of
it beyond its elastic limit & leave it with high & unrelieved internal
stresses. Those residual stresses will, under cyclic rowing loads,
gradually relieve themselves by the rigger shape returning partly to its
former shape. And those stresses will combine with the cyclic service
stresses to drastically reduce the fatigue life of the rigger structure
- especially with welded riggers, which already contain severe locked in
stresses from unrelieved weld contraction. So bending is a crazy & a
damaging way to approximate a result which you can achieve with perfect
accuracy & permanence with a system such as AxioR + AeRoWing

C

--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
Email: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)


17 Jan 2007 00:59:43
PeteC
Re: Adjusting the rigging for a men's club 8 - advice needed.

Carl,

Thank you for your detailed reply. It will come in very useful -
though it would have been even mroe useful if you'd actually answered
the question!

I have one question: if we can't trust the saxboards, or the tracks, or
the decks to be level, how does using a spirit level help? Surely I
have to have some way of knowing that the boat is level before I can
use a spirit level to judge whether the saxboards or tracks are?

By the way, I think it was Pete W who made the comment about bending
riggers. Certainly wasn't me.

Pete

> 2. Error amplification:
> Your tracks may be from 165mm (single) to 300mm (eight) apart,
> centre-centre, whereas your pins are between 1580mm (single) & 1760mm
> (pair) apart, measured across the boat, so any error in levels of tracks
> across the boat, or registration of height gauge in the tracks, will
> tend to amplify. Thus a 1mm error between tracks or gauge location in
> tracks, due e.g. to one track being slightly sprung away from the deck
> or having some dirt beneath it, may amplify into >10mm across the boat.
>
> 3. Manufacturing tolerances:
> There may be small variations in slide bed & saxboard/gunwale top edge
> alignment, as previously discussed. In some crew shells, even from big
> name manufacturers, it is not absolutely guaranteed that the tops of the
> saxboards/gunwales will be either straight or level. This does not mean
> the boat is twisted but does mean you should not absolutely rely on
> their accuracy unless you have checked it. A simple check with a spirit
> level - both across the tops of the tracks & across the sax tops - will
> tell you, provided you can properly read the level (surprisingly many
> don't take enough care!). Use a short level & 2 visibly straight bars,
> which have been checked for straightness by sighting along them, for
> these measurements, with the boat supported in trestles & rigidly
> chocked by sticks to the ground to prevent wobbling. And please
> understand that the typical angular range between the bubble just
> touching one hairline & it just touching the other hairline is 1 degree,
> or ~1 in 57, which can cause an error in relative oarlock heights of ~3cm!
>
> 4. Apply other means to check your result:
> If you think you have done everything right on any boat with more than 2
> riggers, there is still one final test to perform. Having rigged
> everyone to the same height, swing all oarlocks inwards and squat a good
> distance ahead of the boat. Then look straight through/past every
> oarlock on one side, then on the other, then on both: are they all in
> perfect alignment? If not, you got it wrong & need to go back & find
> out why.
>
> 5. Beware human deformity!:
> If rigging a single, remember that we are not normally symmetrical.
> This is a problem which I find is completely ignored, yet it may
> completely blight a promising sculling career. One buttock may be
> larger than the other, bone structure may be more pronounced on one
> side, you may have slight lateral spinal curvature, etc. So it is
> possible to rig a single (& other boats) seemingly perfectly yet still
> find you can't get one blade off the water - because the asymmetry of
> your contact with the seat forces the boat to tilt if you sit up
> straight. The only satisfactory way to resolve this is to tilt the
> seat, raising the side of it on which the rigger seems in use to be too
> high, either by shimming between one side of the seat & the
> undercarriage, or by shimming under that slide track. And you would be
> amazed how much difference even a 1mm shim can make to how the boat sits
> & how comfortable you are (see section 2, above, on error amplification).
>
> HTH
> Carl
>
> PS PeterC, may I refer back to your comments in your 29 December posting?
> Yes, I do think that bending riggers is a daft way to adjust pitch. I
> accept that, if the riggers you have to use provide no other way of
> adjustment, that's what you must do. But I do not accept that it is
> sensible or rational to accept this as normal. Any rigger you can bend
> is one that will itself bend under use & whose life is correspondingly
> shortened. Each time you bend a rigger to re-pitch, you take a part of
> it beyond its elastic limit & leave it with high & unrelieved internal
> stresses. Those residual stresses will, under cyclic rowing loads,
> gradually relieve themselves by the rigger shape returning partly to its
> former shape. And those stresses will combine with the cyclic service
> stresses to drastically reduce the fatigue life of the rigger structure
> - especially with welded riggers, which already contain severe locked in
> stresses from unrelieved weld contraction. So bending is a crazy & a
> damaging way to approximate a result which you can achieve with perfect
> accuracy & permanence with a system such as AxioR + AeRoWing
>
> C
>
> --
> Carl Douglas Racing Shells -
> Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
> Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
> Email: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
> URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)



17 Jan 2007 02:22:14
Teaplant
Re: Adjusting the rigging for a men's club 8 - advice needed.


> By the way, I think it was Pete W who made the comment about bending
> riggers. Certainly wasn't me.
>

Errrm. Sorry, it was me that first suggested including the ScaFFoLd
PiPe (TM) e-z-twist pin orientation management system in your rigging
kit. Carl's widget is certainly the better way to do it if your rigger
is the right style, but as I said at the time, the economics of the
situation often prod you towards other alternatives.

However you 'rig out' life's little twists and bends, rowers are
neither symmetrical nor perfect. So long as the boat and its rig are
good enough for the rower and his technique (with a little room for
improvement of the latter) then everyone has a chance to go a bit
quicker/straighter/better.

Teaplant



17 Jan 2007 12:33:43
Carl
Re: Adjusting the rigging for a men's club 8 - advice needed.

PeteC wrote:
> Carl,
>
> Thank you for your detailed reply. It will come in very useful -
> though it would have been even mroe useful if you'd actually answered
> the question!

Actually, I doubt it!

You may ask the question, but this is a news/discussion group where
answers are not required conform to the questioner's narrow demands. If
I had a straight answer you'd get it, but I'd expect search engines to
do that for you.

What search engines won't do, but a discussion group may, is to widen
understanding of what underlies a question. Discussions of this kind
share that information with all readers, not just you, so should bring
in information which will be of interest to the group. And my opening
remarks did explain exactly why such an understanding might help one to
make better use of an instrument, as well as indicating pitfalls
>
> I have one question: if we can't trust the saxboards, or the tracks, or
> the decks to be level, how does using a spirit level help? Surely I
> have to have some way of knowing that the boat is level before I can
> use a spirit level to judge whether the saxboards or tracks are?
>

Which shows exactly why I wrote as I did! You'd thought you could trust
something & find that may not necessarily be so. So my effort was not
wasted :) .

A golden rule in measurement is "Never assume, always b-well check!" So
obey always these rules:
1. First chock up the boat so it can't move!
2. Make sure no one else will touch the boat while you're working on it.
3. Be sure that you never lean on it either.

Next, make check that the tools you will use are reliable. On a flat
(not necessarily level) surface, does the spirit level read the same
after you rotate it through 180 degrees in the horizontal plane? If
not, then either reject it & get a better one, or label it so that you
always use it the same way round. And the bar(s) you are going to use
across the saxboards (& if necessary across the tracks) - are they
really dead straight & stiff enough not to sag? First apply the same
180 degree test with the spirit level on the bar. Then lay the bar
across the saxboards and compare how the level reads when it is over one
saxboard against when it is over the middle of the boat.

Now you have to make a reasoned choice of one, just one, reference point
for "level". To inform your choice, check the transverse level at
various points along & inside the boat. Then you must decide which one
seems closest to average & keep with it thereafter. To avoid having to
keep rotating the boat, accept that it is leaning one way or the other
and mark the corresponding bubble position in the spirit level with a
couple of small pieces of masking tape. At that point you must mark
even a good spirit level to ensure that you do not reverse it during
subsequent measurements.

Next, eyeball along the tops of the saxboards. Identify if they're
straight in the horizontal plane, or whether one or the other dips or
rises at any point. Forewarned is forearmed. Mark potential trouble
spots with tape so you know where to take corrective action.

Then, measure down from the saxboards to the same point on each seat
when in its frontstops position - you may perhaps find that they are not
all at the same level, even if/though the tracks are.

Finally, if sax levels are not all the same, whittle yourself a thin ,
gently tapered wedge to slide under one or other end of your long bar to
bring the spirit level bubble to the same position each time

When measuring rigger height, you now have all necessary tools:
1. Lay the bar square across the boat in line with the pin, with spirit
level correctly positioned on top of it (by all means attach it
temporarily with a bit of tape to stop it falling into & damaging the boat).
2. Shim the bar to get the spirit bubble into the "level" position that
you have already marked.
3. Measure down to the seat from the _top_ of the bar - do not apply any
weight to the bar as it may bend. Call that measurement A.
4. Eyeball along the top surface of the bar when standing beyond the
oarlock in question, & mark with tape, pencil or pen where the line of
the bar intersects with the oarlock (remember, you are measuring an
eight, & eights have their work set only 2-3 inches above the saxboards,
so unless you bar is unfeasibly thin you should be able to follow this
instruction, whereas it wouldn't work for a single unless your bar was
at least 3" deep, or more)
5. Then measure from your mark to the lower pulling corner of the
oarlock. Call that measurement B
6. Add A to B for the actual work height above that particular seat.
When you have recorded all your measurements, you can move height
washers to get the required heights

Better still (unless seat heights are all over the place!), first set up
all oarlocks to the same height, as above. Then stand away from one end
of the boat & sight along to check that all oarlocks really are in line.
And only after performing that check, start setting individual heights
to suit the rowers.

> By the way, I think it was Pete W who made the comment about bending
> riggers. Certainly wasn't me.

Ooops! Please accept my apologies for my misread.

Cheers -
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: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)


17 Jan 2007 18:45:59
Henning Lippke
Re: Adjusting the rigging for a men's club 8 - advice needed.

PeteC wrote:
> Does anyone know where one can buy the above-mentioned empacher-style
> height tool that sits in the tracks? Been looking for one for ages.

The only Empacher tool I know of is that ridiculous device that we call
'the truth'.

What you are looking for is probably something like this:
http://www.schroederrowing.de/assets/images/a45.jpg
Though I think there are a few better versions & dealers out there.

Or if you have lots of money available:
http://www.active-tools.com/rowing_tools/laser_beam_height_gauge.aspx

Although these tools look very advanced (and certainly are) they work
only as good as their operator. So make sure your boat fits into the
assumptions of the manuals & and apply at least some of Carl's tips.
The self-centering span gauge (my favourite) is quite nice.


18 Jan 2007 11:37:43
Carl
Re: Adjusting the rigging for a men's club 8 - advice needed.

Henning Lippke wrote:
> PeteC wrote:
>
>> Does anyone know where one can buy the above-mentioned empacher-style
>> height tool that sits in the tracks? Been looking for one for ages.
>
>
> The only Empacher tool I know of is that ridiculous device that we call
> 'the truth'.
>
> What you are looking for is probably something like this:
> http://www.schroederrowing.de/assets/images/a45.jpg
> Though I think there are a few better versions & dealers out there.
>
> Or if you have lots of money available:
> http://www.active-tools.com/rowing_tools/laser_beam_height_gauge.aspx
>
> Although these tools look very advanced (and certainly are) they work
> only as good as their operator. So make sure your boat fits into the
> assumptions of the manuals & and apply at least some of Carl's tips.
> The self-centering span gauge (my favourite) is quite nice.

Couldn't agree more, Henning. And you'll see that both of these tools
incorporates the unfounded assumption that the tracks, or the saxboards,
will provide true & level transverse datum lines at every part of the boat.

As always, the proper test is: "Do the oarlocks actually line up all
along each side of the boat?" No amount of fancy kit will give you that
if there are variations in level from place to place, & I wonder how
many crappy outings & unwarranted blame on individual rowers for poor
blade-work have resulted from someone's unfounded faith in the numbers
read from gauges?

I omitted a handy short-cut on rigging an eight or quad:
If you get the 2 end positions on each side of the boat right for
height, spread & lateral pitch, you can use the line of sight trick to
set the other riggers & have complete confidence in their accuracy
without ever using a measuring tool in those positions.

For sculling boats (singles upwards), you can set stern pitch on one
side & then use the line of sight across the boat to set the stern
pitch(es) on the other side. It is not well understood that the human
eye can detect extremely small angular differences, as between the pitch
of 2 oarlocks when one is sillouhetted behind the other, & do so to a
much better accuracy than is normally possible with rigging tools.

Cheers -
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: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)