25 Jun 2004 05:57:15
mxl
Boom Height

I'm relatively new to the sport and currently very confused about boom
height. The rigging guide that came with my NP sail as well as "Turn for
the Better" DVD recommend a lower boom and (forward mast step) position in
high wind (potenitally overpowered) conditions and vice versa. However,
the May issue of windsurfing has Bruce Peterson (head sail designer for
Sailworks) talking about a HIGHER boom position for overpowered conditions
and low boom in light wind.. Everyone agrees on the mast step position.
Please clarify the boom issue. It makes sense to me to have the boom higher
in overpowered conditions as it would provide more leverage, but I'm not
sure.

Thanks in advance
Mark




25 Jun 2004 13:01:34
BarryWind
Re: Boom Height

I saw the same article. The editor may have confused [edited] what Bruce was
trying to get across...

Everything else equal and based on my humble experience, when you move the
mast step forward, the booms need to come up a bit to compensate for the
increased sail rake that essentially lowers the booms. The opposite is true,
booms go up, for moving the mast back.

Other than the leverage factor, which I feel is really way down on the
effects list, boom height really impacts the front to back weight
distribution on the feet. Leaving the mast step position fixed, lowering the
booms tends to weight the front foot more and higher booms tend to shift the
weight back to the rear foot.

There's quite a range of boom height / mast step position combinations that
work when you factor in personal preference too.

Example of this: At this year's Open, out of desperation to gain some
control [a.k.a. keep the board's nose down] during the first day of racing.
I downhauled too much, a lesser of two evils tradeoff, but I also put my
mast foot all the way forward and raised the booms 2" more than I usually
do. The improvement was noticeable in the second race, after tail walking
the entire first race with my mast foot too far back and booms too low.

-B

"mxl" <lyubkin@hotmail.com > wrote in message
news:%8PCc.28255$eH1.13355741@newssvr28.news.prodigy.com...
> I'm relatively new to the sport and currently very confused about boom
> height. The rigging guide that came with my NP sail as well as "Turn for
> the Better" DVD recommend a lower boom and (forward mast step) position in
> high wind (potenitally overpowered) conditions and vice versa. However,
> the May issue of windsurfing has Bruce Peterson (head sail designer for
> Sailworks) talking about a HIGHER boom position for overpowered conditions
> and low boom in light wind.. Everyone agrees on the mast step position.
> Please clarify the boom issue. It makes sense to me to have the boom
higher
> in overpowered conditions as it would provide more leverage, but I'm not
> sure.
>
> Thanks in advance
> Mark




25 Jun 2004 13:22:22
BarryWind
Re: Boom Height

Heck, I have to hack/edit my own posting... [see ** DOWN** below]. Good
thing I'm not a magazine editor...
-B

"BarryWind" <barrywindZ@earthlink.net > wrote in message
news:OmVCc.460$lh4.305@newsread1.news.pas.earthlink.net...
...snip...
> Everything else equal and based on my humble experience, when you move the
> mast step forward, the booms need to come up a bit to compensate for the
> increased sail rake that essentially lowers the booms. The opposite is
true,
> booms go ** DOWN **, for moving the mast back.




26 Jun 2004 17:15:06
Mike F
Re: Boom Height

I set my boom height so that, with the short harness line length I prefer, I
can hook in and unhook without having to close the gap first or jump into
the air. For me, that means a bit below collarbone height as I stand beside
an upright mast. Because my collarbones. Your mileage may vary. Since my
height doesn't change on very windy or lighter days, neither does my boom
height. And since we rig to attain more or less a given amount of power
whether it's windy or less so, I don't feel I need diffedrent amounts of
leverage one sail size to another. Whether that applies to giant sails I
don't know.



Mike m/



"mxl" <lyubkin@hotmail.com > wrote in message
news:%8PCc.28255$eH1.13355741@newssvr28.news.prodigy.com...
> I'm relatively new to the sport and currently very confused about boom
> height. The rigging guide that came with my NP sail as well as "Turn for
> the Better" DVD recommend a lower boom and (forward mast step) position in
> high wind (potenitally overpowered) conditions and vice versa. However,
> the May issue of windsurfing has Bruce Peterson (head sail designer for
> Sailworks) talking about a HIGHER boom position for overpowered conditions
> and low boom in light wind.. Everyone agrees on the mast step position.
> Please clarify the boom issue. It makes sense to me to have the boom
higher
> in overpowered conditions as it would provide more leverage, but I'm not
> sure.
>
> Thanks in advance
> Mark
>
>



27 Jun 2004 17:05:35
Juri Munkki
Re: Boom Height

In article <10ds4bqflqclo6e@corp.supernews.com > "Mike F" <mikes.newS@charUrshortz_ter.net> writes:
>I set my boom height so that, with the short harness line length I prefer, I
>can hook in and unhook without having to close the gap first or jump into
>the air. For me, that means a bit below collarbone height as I stand beside
>an upright mast. Because my collarbones. Your mileage may vary. Since my
>height doesn't change on very windy or lighter days, neither does my boom
>height. And since we rig to attain more or less a given amount of power
>whether it's windy or less so, I don't feel I need diffedrent amounts of
>leverage one sail size to another. Whether that applies to giant sails I
>don't know.

Some of the power goes through the mast foot to the board.

When you move the boom up, you usually have to move the harness lines back.
I think the reason the harness lines have to go back is that more of the
force goes through the mast foot... or maybe it's because the center of
effort isn't a point, but more of a line or area and when you move the boom
up, the intersection of that line with your boom is on a different place on
the boom.

In any case, the "high boom, harness lines back" solution has a totally
different, but still balanced feel to it: the leading edge of the sail
seems to have more of a life of its own. With the low boom, harness lines
forward version, the sail seems to pivot more around the mast.

Once you get the boom high enough and the harness lines right (the harness
lines are _very_ important here...if you move the boom up and leave the
lines where they were, it does _not_ work), things sort of click into
place and the sail locks into a very efficient position and also puts
you into a good stance.

With a low boom, there's another "sweet spot" where things seem to
work pretty well. I think the middle grouns is where it gets murky and
it's difficult to find a good stance & balance. The current wisdom is
that higher booms are faster.

Let's take a poll though:

A: Back/front foot balance:

1) All of the load is on the back foot
2) Most of the load is on the back, but some on the front
3) The feet have equal load
4) The front foot is more loaded than the back foot
5) Neither foot has a heavy load
6) Other

B: Boom height:

1) Relative to my height, I have the boom high in the opening
2) Relative to my height, I have the boom near the middle
3) Relative to my height, I have the boom low

I used to have A3B3 with my (narrow) freeride board, but I'm now
at A1-3B1-2, depending on the rig and conditions. In additon to
boom height & harness line positions, the way the sail is rigged
and the power of the fin seem to affect the foot balance. A less
powerful fin seems to give a more equal balance between the feet.

--
Juri Munkki jmunkki@iki.fi What you see isn't all you get.
http://www.iki.fi/jmunkki Windsurfing: Faster than the wind.


27 Jun 2004 14:45:22
BarryWind
Re: Boom Height

Don't mean to confuse you, but here's another spin on boom height.
Unless you're lucky and always get perfect Shangri-La conditions, you'll
probably find that boom height is a variable and not just a fixed setting.
1) If you know that you'll be non-planing quite a bit, wave sailing in light
conditions or when your biggest sail isn't big enough to consistently plane,
low boom settings allow you to hook-in easier. Although you can offset this
if you run adjustable harness lines and lengthening the lines. Sorry to
preach, but adjustable harness lines are on every boom I own.
2) If the wind picks up and you need a way to cope with a board that is
becoming hard to control, quick fix is to lower the booms. This will
transfer more weight onto the front foot and help keep the nose down.
3) However, if you're having BOTH board AND sail-control issues, then just
lowering the boom might not be enough. You might need to also move the mast
foot forward. If you can't sheet-in the sail, because you're overpowered,
higher booms [offset by moving the mast step forward] allow you to hang
additional body-weight from the booms and use mast foot pressure to help
hold the board's nose down. [A sheeted-in sail holds a board's nose down and
a sheeted-out sail makes the nose light and tail heavy].
Best thing to do is experiment with boom height and mast step settings to
see what works.
-B

"mxl" <lyubkin@hotmail.com > wrote in message
news:%8PCc.28255$eH1.13355741@newssvr28.news.prodigy.com...
> I'm relatively new to the sport and currently very confused about boom
> height. The rigging guide that came with my NP sail as well as "Turn for
> the Better" DVD recommend a lower boom and (forward mast step) position in
> high wind (potenitally overpowered) conditions and vice versa. However,
> the May issue of windsurfing has Bruce Peterson (head sail designer for
> Sailworks) talking about a HIGHER boom position for overpowered conditions
> and low boom in light wind.. Everyone agrees on the mast step position.
> Please clarify the boom issue. It makes sense to me to have the boom
higher
> in overpowered conditions as it would provide more leverage, but I'm not
> sure.
>
> Thanks in advance
> Mark




27 Jun 2004 15:09:15
BarryWind
Re: Boom Height

Juri,

Good point about harness lines moving back with a higher boom. My wife,
about 8-in [20cm] shorter than me, always moves the harness lines about 2-in
[5cm] forward from my setting.
It's interesting how many variables can be changed to allow a sail's force
to properly line up and give that 'dialed-in' feeling. Footstrap placement
also enters into the equation to make things even more complicated. I guess
the 'feel' thing is a problem - it's very subjective.
However, I never set my booms for hook-in convenience unless I know that
I'll be schlogging quite a bit.
And on my race gear, I've been creeping my booms up lately to find a new
sweet-spot solution. I don't know if this is because I'm better able to sail
overpowered with the same sail as I get [ever so slowly] better, or if I've
been sailing with my booms to low all along...

MXL,

Guess we're guilty as hell for giving you a more confusing than amusing
complicated answer to a complicated issue. Let's summarize boom height
settings. It all depends on:
Personal preference, degree of sail power, board size, fin size, mast foot
placement, harness line length and placement, and footstrap placement. What
else did I forget...?

B^)

"Juri Munkki" <jmunkki@cc.hut.fi > wrote in message
news:cbmk7f$o7g$1@epityr.hut.fi...
> When you move the boom up, you usually have to move the harness lines
back.
> I think the reason the harness lines have to go back is that more of the
> force goes through the mast foot... or maybe it's because the center of
> effort isn't a point, but more of a line or area and when you move the
boom
> up, the intersection of that line with your boom is on a different place
on
> the boom.
>
> In any case, the "high boom, harness lines back" solution has a totally
> different, but still balanced feel to it: the leading edge of the sail
> seems to have more of a life of its own. With the low boom, harness lines
> forward version, the sail seems to pivot more around the mast.
>
> Once you get the boom high enough and the harness lines right (the harness
> lines are _very_ important here...if you move the boom up and leave the
> lines where they were, it does _not_ work), things sort of click into
> place and the sail locks into a very efficient position and also puts
> you into a good stance.
>
> With a low boom, there's another "sweet spot" where things seem to
> work pretty well. ...snip...




27 Jun 2004 11:45:24
Mike F
Re: Boom Height

At what instant? My footwork is almost as dynamic in WSing as it is in
basketball, working the board up and down, right and left, round and round,
controlling and changing pitch, roll, and yaw constantly. I presume that's
even more true of wave sailors, and maybe of people who surf swell out of
one or both straps.

Mike m/

"Juri Munkki" <jmunkki@cc.hut.fi > wrote >
> Let's take a poll though:
>
> A: Back/front foot balance:
>
> 1) All of the load is on the back foot
> 2) Most of the load is on the back, but some on the front
> 3) The feet have equal load
> 4) The front foot is more loaded than the back foot
> 5) Neither foot has a heavy load
> 6) Other



28 Jun 2004 19:57:28
mxl
Re: Boom Height

This makes sense to me, Barry. Thanks everyone for lively discussion; it
was helpful.

Mark


"BarryWind" <barrywindZ@earthlink.net > wrote in message
news:64BDc.15207$w07.2696@newsread2.news.pas.earthlink.net...
> Don't mean to confuse you, but here's another spin on boom height.
> Unless you're lucky and always get perfect Shangri-La conditions, you'll
> probably find that boom height is a variable and not just a fixed setting.
> 1) If you know that you'll be non-planing quite a bit, wave sailing in
light
> conditions or when your biggest sail isn't big enough to consistently
plane,
> low boom settings allow you to hook-in easier. Although you can offset
this
> if you run adjustable harness lines and lengthening the lines. Sorry to
> preach, but adjustable harness lines are on every boom I own.
> 2) If the wind picks up and you need a way to cope with a board that is
> becoming hard to control, quick fix is to lower the booms. This will
> transfer more weight onto the front foot and help keep the nose down.
> 3) However, if you're having BOTH board AND sail-control issues, then just
> lowering the boom might not be enough. You might need to also move the
mast
> foot forward. If you can't sheet-in the sail, because you're overpowered,
> higher booms [offset by moving the mast step forward] allow you to hang
> additional body-weight from the booms and use mast foot pressure to help
> hold the board's nose down. [A sheeted-in sail holds a board's nose down
and
> a sheeted-out sail makes the nose light and tail heavy].
> Best thing to do is experiment with boom height and mast step settings to
> see what works.
> -B
>
> "mxl" <lyubkin@hotmail.com> wrote in message
> news:%8PCc.28255$eH1.13355741@newssvr28.news.prodigy.com...
> > I'm relatively new to the sport and currently very confused about boom
> > height. The rigging guide that came with my NP sail as well as "Turn
for
> > the Better" DVD recommend a lower boom and (forward mast step) position
in
> > high wind (potenitally overpowered) conditions and vice versa.
However,
> > the May issue of windsurfing has Bruce Peterson (head sail designer for
> > Sailworks) talking about a HIGHER boom position for overpowered
conditions
> > and low boom in light wind.. Everyone agrees on the mast step position.
> > Please clarify the boom issue. It makes sense to me to have the boom
> higher
> > in overpowered conditions as it would provide more leverage, but I'm not
> > sure.
> >
> > Thanks in advance
> > Mark
>
>




29 Jun 2004 19:38:15
The Dennises
Re: Boom Height

On my big board (81 wide free formula) I find myself sailing with high boom
(mouth height, but I'm short so that's at the middle of the cutout), medium
to longish lines (adjustable), seat harness, mast foot centre to just
forward of centre, footstraps all the way back and outboard, most of my
weight on the back foot .
On my small boards I use a waist harness and short lines 18 to 20", and
single back strap. Boom is about clavicle height. Most weight on the back
foot still but more on top of the board. I sail mostly flat to choppy bay
conditions.


"Juri Munkki" <jmunkki@cc.hut.fi > wrote in message
news:cbmk7f$o7g$1@epityr.hut.fi...
> In article <10ds4bqflqclo6e@corp.supernews.com> "Mike F"
<mikes.newS@charUrshortz_ter.net > writes:
> >I set my boom height so that, with the short harness line length I
prefer, I
> >can hook in and unhook without having to close the gap first or jump into
> >the air. For me, that means a bit below collarbone height as I stand
beside
> >an upright mast. Because my collarbones. Your mileage may vary. Since my
> >height doesn't change on very windy or lighter days, neither does my boom
> >height. And since we rig to attain more or less a given amount of power
> >whether it's windy or less so, I don't feel I need diffedrent amounts of
> >leverage one sail size to another. Whether that applies to giant sails I
> >don't know.
>
> Some of the power goes through the mast foot to the board.
>
> When you move the boom up, you usually have to move the harness lines
back.
> I think the reason the harness lines have to go back is that more of the
> force goes through the mast foot... or maybe it's because the center of
> effort isn't a point, but more of a line or area and when you move the
boom
> up, the intersection of that line with your boom is on a different place
on
> the boom.
>
> In any case, the "high boom, harness lines back" solution has a totally
> different, but still balanced feel to it: the leading edge of the sail
> seems to have more of a life of its own. With the low boom, harness lines
> forward version, the sail seems to pivot more around the mast.
>
> Once you get the boom high enough and the harness lines right (the harness
> lines are _very_ important here...if you move the boom up and leave the
> lines where they were, it does _not_ work), things sort of click into
> place and the sail locks into a very efficient position and also puts
> you into a good stance.
>
> With a low boom, there's another "sweet spot" where things seem to
> work pretty well. I think the middle grouns is where it gets murky and
> it's difficult to find a good stance & balance. The current wisdom is
> that higher booms are faster.
>
> Let's take a poll though:
>
> A: Back/front foot balance:
>
> 1) All of the load is on the back foot
> 2) Most of the load is on the back, but some on the front
> 3) The feet have equal load
> 4) The front foot is more loaded than the back foot
> 5) Neither foot has a heavy load
> 6) Other
>
> B: Boom height:
>
> 1) Relative to my height, I have the boom high in the opening
> 2) Relative to my height, I have the boom near the middle
> 3) Relative to my height, I have the boom low
>
> I used to have A3B3 with my (narrow) freeride board, but I'm now
> at A1-3B1-2, depending on the rig and conditions. In additon to
> boom height & harness line positions, the way the sail is rigged
> and the power of the fin seem to affect the foot balance. A less
> powerful fin seems to give a more equal balance between the feet.
>
> --
> Juri Munkki jmunkki@iki.fi What you see isn't all you get.
> http://www.iki.fi/jmunkki Windsurfing: Faster than the wind.