Mast Rake and Mast Bend
 

Mast rake is the angle from vertical, fore and aft. In other words,
when you are looking at the boat from exactly abeam. Increasing mast
rake helps pointing but as always, there's a trade-off. Increased mast
rake hurts off-wind performance and also hurts light air performance.

I happen to the think that mast rake is often overdone. Having worked
at tuning bunches of different one-design boats, it's all too easy to
just lengthen the forestay, and see a slight improvement in pointing
as the answer to my prayers when it really doesn't help me at the
finish line. In fact, several times I have said to the crew "Let's
start all over from scratch, stand the mast up straight, and begin
raking it little by little to find what we need." And wow! Suddenly
the boat is moving like it should be!

An exception is the Hobie 16. Because the rudders are the most
effective part of the underwater foil, getting the sail area as far
aft, over the rudders, as possible, makes the boat go to windward much
much better. It also makes the boat easier to tack, which can be a
major factor. The limiting factor in mast rake here is that the boom
drags on the aft cross beam, and most Hobie 16 racers sail with it
there.

Remember too that the mast is a long lever... if you make a millimeter
adjustment at deck level, the top of the mast will move a lot further.
I think this is why so many people overdo it.

Mast bend.... bending the mast fore-and-aft will pull the mainsail
flatter along the leading edge, and if everything else stays the same,
will also open up the leach. Many keelboats are tuned so that
increasing backstay tension bends the mast, with masthead rigs this
depends on either a babystay or adjusting lowers; with a frac rig the
backstay will bend the upper mast. To get fancy, some boats have
running backstay and/or checkstays which limit how much the mast bends
at some particular point. To depower the sail, bending the upper mast
will help. Bending the lower mast will flatten the largest part of the
main (remember the cunningham may need to be re-adjusted) and also
have the same effect as increasing rake.

Remember too that any time you increase tension aft on the mast, with
the backstay, running back, or even the leach of the mainsail, the
luff of the jib is going to also be affected. Everything is connected
to everything else, this is why it is important to *small* tuning
adjustments until you are sure what the overall result will be.

BTW getting back to the subject of weatherliness, I walked around the
docks at our marina yesterday (yes we went down to the boat on a
weekday) and looked sheet tracks. Only about 25% of the boats had
headsail sheeting arrangements that looked reasonably efficient. Most
productions boats had half-measures designed partially for sailing and
partially for cost control and partially to keep the crew from
stubbing their toes.

Fresh Breezes- Doug King

Mast Rake and Mast Bend
 

Remember too that any time you increase tension aft on the mast, with
the backstay, running back, or even the leach of the mainsail, the
luff of the jib is going to also be affected.

Oh my!

RB

Mast Rake and Mast Bend
 

Remember too that the mast is a long lever... if you make a millimeter
adjustment at deck level, the top of the mast will move a lot further.
I think this is why so many people overdo it.


Holy leaping toads!

RB

Mast Rake and Mast Bend
 

Increased mast
rake hurts off-wind performance and also hurts light air performance.



Wowzer rats! Really?


RB

Mast Rake and Mast Bend
 

Bobsprit wrote:

Increased mast
rake hurts off-wind performance and also hurts light air performance.

Wowzer rats! Really?

RB

Well Bob, those were three really useful and informative comments.

Now explain to us exactly how increased rake causes a deterioration in
downwind performance and what can be done to offset this, (without removing
the rake). No google.

Ready, set,, go!

Now I know some of you will want to jump in here and answer, don't, let
Bob come up with the answers himself!

Cheers
Marty

Mast Rake and Mast Bend
 

Martin Baxter wrote:


Well Bob, those were three really useful and informative comments.

Now explain to us exactly how increased rake causes a deterioration in
downwind performance and what can be done to offset this, (without removing
the rake). No google.

Ready, set,, go!

Now I know some of you will want to jump in here and answer, don't, let
Bob come up with the answers himself!

I know, I know!! Mount an anchor on the companionway hatch cover!

This has been proven to increase downwind speed every time, regardless of mast
rake!

DSK

Mast Rake and Mast Bend
 

DSK wrote:

Martin Baxter wrote:


Well Bob, those were three really useful and informative comments.

Now explain to us exactly how increased rake causes a deterioration in
downwind performance and what can be done to offset this, (without removing
the rake). No google.

Ready, set,, go!

Now I know some of you will want to jump in here and answer, don't, let
Bob come up with the answers himself!

I know, I know!! Mount an anchor on the companionway hatch cover!

This has been proven to increase downwind speed every time, regardless of mast
rake!

DSK

Jeeze Doug, I asked you not to help! ;-0~

Cheers
Marty

Mast Rake and Mast Bend
 

Chrome anchor nitwit. That's the only one that'll work!

"DSK" wrote in message
...
Martin Baxter wrote:


Well Bob, those were three really useful and informative comments.

Now explain to us exactly how increased rake causes a deterioration in
downwind performance and what can be done to offset this, (without
removing
the rake). No google.

Ready, set,, go!

Now I know some of you will want to jump in here and answer, don't, let
Bob come up with the answers himself!

I know, I know!! Mount an anchor on the companionway hatch cover!

This has been proven to increase downwind speed every time, regardless of
mast
rake!

DSK

Mast Rake and Mast Bend
 

DSK wrote:

Mast rake is the angle from vertical, fore and aft. In other words,
when you are looking at the boat from exactly abeam. Increasing mast
rake helps pointing but as always, there's a trade-off.

Good lord he's actually gone away, read a little and learnt from my
earlier posts! Will wonders never cease! Today is a day of enlightenment
for Doug!

Hip hip Hooray!



Mast bend.... will pull the mainsail
flatter along the leading edge,

Great now he's finally got it right!

Only about 25% of the boats had
headsail sheeting arrangements that looked reasonably efficient. Most
productions boats had half-measures designed partially for sailing and
partially for cost control and partially to keep the crew from
stubbing their toes.

And how did you decide that? More self aggrandizement perhaps?

Cheers

Mast Rake and Mast Bend
 

Bobsprit wrote:

Remember too that any time you increase tension aft on the mast, with
the backstay, running back, or even the leach of the mainsail, the
luff of the jib is going to also be affected.

Oh my!



Indeed. He has an amazing capacity to reiterate that which has already
been posted.

Cheers

Mast Rake and Mast Bend
 

Bobsprit wrote:

Remember too that the mast is a long lever... if you make a millimeter
adjustment at deck level, the top of the mast will move a lot further.
I think this is why so many people overdo it.


Holy leaping toads!


Yes. I agree.

Cheers

Mast Rake and Mast Bend
 

Bobsprit wrote:

Increased mast
rake hurts off-wind performance and also hurts light air performance.



Wowzer rats! Really?


LOL. C'mon Doug. Justify your generality, after all you imply you know
more about sail trim than anyone else!

Cheers

Mast Rake and Mast Bend
 

MC wrote:

.... you imply you know
more about sail trim than anyone else!

Nope, I never implied anything like that. If true, I'd be a world champion and
Olympic medallist in bunches of classes, and famous.

However, it's pretty easy to deduce that I know more about sail trim than you
do.

DSK

Mast Rake and Mast Bend
 

DSK wrote:

Martin Baxter wrote:


Well Bob, those were three really useful and informative comments.

Now explain to us exactly how increased rake causes a deterioration in
downwind performance and what can be done to offset this, (without removing
the rake). No google.

Ready, set,, go!

Now I know some of you will want to jump in here and answer, don't, let
Bob come up with the answers himself!


I know, I know!! Mount an anchor on the companionway hatch cover!

This has been proven to increase downwind speed every time, regardless of mast
rake!


Quiet Doug, people who sail are talking.

Cheers

Mast Rake and Mast Bend
 

"MC" wrote in message
...
Bobsprit wrote:
Remember too that any time you increase tension aft on the mast, with
the backstay, running back, or even the leach of the mainsail, the
luff of the jib is going to also be affected.

Oh my!


Indeed. He has an amazing capacity to reiterate that which has already
been posted.


He's almost life-like!

Mast Rake and Mast Bend
 

DSK wrote:

MC wrote:


.... you imply you know
more about sail trim than anyone else!


Nope, I never implied anything like that. If true, I'd be a world champion and
Olympic medallist in bunches of classes, and famous.

However, it's pretty easy to deduce that I know more about sail trim than you
do.

Hahahhahaha S'funny, In that case I don't understand why you posted
pictures
of your sailing with such bad sail trim! Why not impress us by posting a
reference
to one of your winds against a world class fleet?

Anyway, stop evading, answer the question or say you don't know the answer!

Cheers

Mast Rake and Mast Bend
 

Jeff Morris wrote:

"MC" wrote in message
...

Bobsprit wrote:

Remember too that any time you increase tension aft on the mast, with
the backstay, running back, or even the leach of the mainsail, the
luff of the jib is going to also be affected.

Oh my!


Indeed. He has an amazing capacity to reiterate that which has already
been posted.



He's almost life-like!


I bet he was real good in the miliary.

Cheers

Mast Rake and Mast Bend
 

MC wrote:

..... I don't understand why you posted
pictures
of your sailing with such bad sail trim!

??? which picture is that, MC?

AFAIK I have posted many pictures, some with not particularly good sail trim as we
are just casually daysailing, and other pictures where sail trim is pretty good.

In no case have I posted pictures of one of my boats sailing, claimed that the sail
trim was perfect, and then had a hissy fit when several better sailors pointed out
the flaws. You've done this twice.

Why not impress us by posting a
reference
to one of your winds against a world class fleet?

Actually, I've posted lnks to my race results several times. You probably weren't
paying attention, seems to be how you go through life without learning much.



Anyway, stop evading, answer the question or say you don't know the answer!

How can I know the answer when I don't know the question? You answer this question
first: WTF are you babbling about?

DSK

Mast Rake and Mast Bend
 

LOL. C'mon Doug. Justify your generality, after all you imply you know
more about sail trim than anyone else!


Which is exactly why I (again) exposed Doug for the pinhead that he is.

RB

Mast Rake and Mast Bend
 

"Bobsprit" wrote in message
...
Remember too that the mast is a long lever... if you make a millimeter
adjustment at deck level, the top of the mast will move a lot further.
I think this is why so many people overdo it.


Holy leaping toads!

Not only do you consistently fail to engage in any sailing discussions, but
you now feel that you must deride the efforts of people who actually make a
real contribution!!

The really strange thing is that you are reduced to Bush- like sentences
when you have one of your sneers.


I found Doug's post quite informative, and I appreciated the effort that he
put into making it easy to understand. Perhaps you found it a bit
difficult, and reacted by hitting out????



Regards


Donal
--

Mast Rake and Mast Bend
 

DSK wrote:

MC wrote:


..... I don't understand why you posted
pictures
of your sailing with such bad sail trim!


??? which picture is that, MC?

AFAIK I have posted many pictures, some with not particularly good sail trim as we
are just casually daysailing, and other pictures where sail trim is pretty good.

In no case have I posted pictures of one of my boats sailing, claimed that the sail
trim was perfect, and then had a hissy fit when several better sailors pointed out
the flaws. You've done this twice.

Good lord, you do have a mental problem don't you?



Why not impress us by posting a
reference
to one of your winds against a world class fleet?


Actually, I've posted lnks to my race results several times. You probably weren't
paying attention, seems to be how you go through life without learning much.



Well I may have missed it but I'm ready to be impressed now. Post the
reference.



Anyway, stop evading, answer the question or say you don't know the answer!


How can I know the answer when I don't know the question? You answer this question
first: WTF are you babbling about?



You can't even remember a question posted just a few hours ago in this
very thread? I think you need medical help.


Cheers

Mast Rake and Mast Bend
 

Donal wrote:



I found Doug's post quite informative, and I appreciated the effort that he
put into making it easy to understand. Perhaps you found it a bit
difficult, and reacted by hitting out????


Hey Donal, can you adjust your mast in it's partners -or is it through
bolted?

Cheers MC

Mast Rake and Mast Bend
 

"MC" wrote in message
...


Donal wrote:



I found Doug's post quite informative, and I appreciated the effort that
he
put into making it easy to understand. Perhaps you found it a bit
difficult, and reacted by hitting out????


Hey Donal, can you adjust your mast in it's partners -or is it through
bolted?

Sorry, that was too complicated for me.

Can you put the question in terms that I can understand?




Regards


Donal
--

Mast Rake and Mast Bend
 

I found Doug's post quite informative,


I'll BET you did! Next up for donal, a lesson in basic sail trim!

Bwahahahahahaha!

RB

Mast Rake and Mast Bend
 

On Wed, 14 Jan 2004 11:18:40 -0500, DSK wrote
this crap:

Now explain to us exactly how increased rake causes a deterioration in
downwind performance and what can be done to offset this, (without removing
the rake). No google.

I know, I know!! Mount an anchor on the companionway hatch cover!

This has been proven to increase downwind speed every time, regardless of mast
rake!

Actually, we open our cabintop hatch and our bow hatch straight up, to
grab more wind while going downwind.




This signature is now the ultimate power in the universe

Mast Rake and Mast Bend
 

Sorry, that was too complicated for me.

Can you put the question in terms that I can understand?

He aint kidden neither!


RB

Mast Rake and Mast Bend
 

On your crapola hunter... sure thing, why not open your dress too.

"Horvath" wrote in message
...
On Wed, 14 Jan 2004 11:18:40 -0500, DSK wrote
this crap:

Now explain to us exactly how increased rake causes a deterioration in
downwind performance and what can be done to offset this, (without
removing
the rake). No google.

I know, I know!! Mount an anchor on the companionway hatch cover!

This has been proven to increase downwind speed every time, regardless of
mast
rake!

Actually, we open our cabintop hatch and our bow hatch straight up, to
grab more wind while going downwind.




This signature is now the ultimate power in the universe

Mast Rake and Mast Bend
 

You know where the mast goes through the deck? Is it fixed in the metal
ring perhaps with a big bolt? It's just that if you were interested in
altering rake my adjustments at deck level it would be impossible with a
bolted partner... Instead you would have to alter rake at the mast foot
and that is also impossible on many boats as the foot casing is welded
or bonded to a ring frame.

Cheers

Donal wrote:

"MC" wrote in message
...


Donal wrote:



I found Doug's post quite informative, and I appreciated the effort that

he

put into making it easy to understand. Perhaps you found it a bit
difficult, and reacted by hitting out????


Hey Donal, can you adjust your mast in it's partners -or is it through
bolted?


Sorry, that was too complicated for me.

Can you put the question in terms that I can understand?




Regards


Donal
--

Mast Rake and Mast Bend
 

Bobsprit wrote:

I found Doug's post quite informative,


I'll BET you did! Next up for donal, a lesson in basic sail trim!


From Doug who doesn't think mast curvature always alters sail shape?

Cheers MC

Mast Rake and Mast Bend
 

Horvath wrote:

On Wed, 14 Jan 2004 11:18:40 -0500, DSK wrote
this crap:


Now explain to us exactly how increased rake causes a deterioration in
downwind performance and what can be done to offset this, (without removing
the rake). No google.


I know, I know!! Mount an anchor on the companionway hatch cover!

This has been proven to increase downwind speed every time, regardless of mast
rake!


Actually, we open our cabintop hatch and our bow hatch straight up, to
grab more wind while going downwind.


Do you make the crew stand up too? We do that in NZ.

Cheers

Mast Rake and Mast Bend
 

You know where the mast goes through the deck? Is it fixed in the metal
ring perhaps with a big bolt?


I don't believe, not for a second, that Donal did not know what you were
talking about.
Nice of you to explain anyway for him.

RB

Mast Rake and Mast Bend
 

Bobsprit wrote:
You know where the mast goes through the deck? Is it fixed in the metal
ring perhaps with a big bolt?


I don't believe, not for a second, that Donal did not know what you were
talking about.
Nice of you to explain anyway for him.



And there was me thinking he was asking for information, espectailly as
he seemed taken with Doug's ideas about how the mast is a lever
amplifing deck level movements. Then again, do you suppose it could be
possible that that Dinghy Doug doesn't know that that bigger yachts with
keel stepped masts do not generally adjust rake at deck level?

Cheers

Mast Rake and Mast Bend
 

On Thu, 15 Jan 2004 14:44:41 +1300, MC wrote this
crap:



Horvath wrote:

On Wed, 14 Jan 2004 11:18:40 -0500, DSK wrote
this crap:


Now explain to us exactly how increased rake causes a deterioration in
downwind performance and what can be done to offset this, (without removing
the rake). No google.


I know, I know!! Mount an anchor on the companionway hatch cover!

This has been proven to increase downwind speed every time, regardless of mast
rake!


Actually, we open our cabintop hatch and our bow hatch straight up, to
grab more wind while going downwind.


Do you make the crew stand up too? We do that in NZ.

And block the sails? That doesn't sound too bright.





This signature is now the ultimate power in the universe

Mast Rake and Mast Bend
 

"MC" wrote in message
...
You know where the mast goes through the deck? Is it fixed in the metal
ring perhaps with a big bolt? It's just that if you were interested in
altering rake my adjustments at deck level it would be impossible with a
bolted partner... Instead you would have to alter rake at the mast foot
and that is also impossible on many boats as the foot casing is welded
or bonded to a ring frame.


I think that there are wooden chocks holding it in a vertical position.

Underneath the mast, there is a metal plate (SS or ally??) with two vertical
plates welded to it. These verticals are either side of the mast, and a
bolt goes through the lot.



Regards

Donal
--

Mast Rake and Mast Bend
 

"MC" wrote in message
...


Bobsprit wrote:
You know where the mast goes through the deck? Is it fixed in the metal
ring perhaps with a big bolt?


I don't believe, not for a second, that Donal did not know what you were
talking about.
Nice of you to explain anyway for him.



And there was me thinking he was asking for information, espectailly as
he seemed taken with Doug's ideas about how the mast is a lever
amplifing deck level movements. Then again, do you suppose it could be
possible that that Dinghy Doug doesn't know that that bigger yachts with
keel stepped masts do not generally adjust rake at deck level?

Ahhhh! I was wondering why you were asking!

I've already sent my answer, but I'm not sure that you will like it.



Regards


Donal
--

Mast Rake and Mast Bend
 

"MC" wrote...
You know where the mast goes through the deck? Is it fixed in the metal
ring perhaps with a big bolt?

Have you seen many keelboats with masts fixed by a thru-bolt at the partners?
This is not a very common arrangement at all over here. In fact I haven't ever
seen one.

...It's just that if you were interested in
altering rake my adjustments at deck level it would be impossible with a
bolted partner... Instead you would have to alter rake at the mast foot
and that is also impossible on many boats as the foot casing is welded
or bonded to a ring frame.

Donal wrote:
I think that there are wooden chocks holding it in a vertical position.

Underneath the mast, there is a metal plate (SS or ally??) with two vertical
plates welded to it. These verticals are either side of the mast, and a
bolt goes through the lot.

Donal it apears that if you were interested in changing the rake of your mast,
or perhaps even shifting the whole mast a little bit forward or aft, it would be
possible (as it is on most properly rigged boats). A little work at the chocks
and/or at the step. However you've always said that your boat sails well, please
don't think I am advocating this.

One thing to take a close look at, before such an undertaking, is what the
structural grid under the mast step is like. Usually (in a properly designed and
built boat) there is allowance for the mast butt to be moved a couple inches,
maybe less, each way; and there is sufficient structural strength to support it.

It seems that MC has never tuned a keelboat and isn't sure how masts are
adjusted; or it may be that his own much-bragged-about has it's mast fixed
rather oddly... perhaps the riggers did it on purpose so that he couldn't mess
it up?

Fresh Breezes- Doug King

Mast Rake and Mast Bend
 

"DSK" wrote in message
...

Donal it apears that if you were interested in changing the rake of your
mast,
or perhaps even shifting the whole mast a little bit forward or aft, it
would be
possible (as it is on most properly rigged boats). A little work at the
chocks
and/or at the step. However you've always said that your boat sails well,
please
don't think I am advocating this.

I've never felt like adjusting the rake. I just find the thread
interesting, because sail trim is still my weak point.

A nice set of those high tech orange sails would be nice. Similiar boats
equipped with them do pass me.





One thing to take a close look at, before such an undertaking, is what the
structural grid under the mast step is like. Usually (in a properly
designed and
built boat) there is allowance for the mast butt to be moved a couple
inches,
maybe less, each way; and there is sufficient structural strength to
support it.


I'll have to take a look. I think that the plate that the mast sits on, is
bolted to the keel. The verticals are welded. So the plate would have to
be moved. It would probably be cheaper and easier to have a new plate
made.


Regards


Donal
--

Mast Rake and Mast Bend
 

Well, you're not very bright, so it fits.

"Horvath" wrote in message
...
On Thu, 15 Jan 2004 14:44:41 +1300, MC wrote this
crap:



Horvath wrote:

On Wed, 14 Jan 2004 11:18:40 -0500, DSK wrote
this crap:


Now explain to us exactly how increased rake causes a deterioration in
downwind performance and what can be done to offset this, (without
removing
the rake). No google.


I know, I know!! Mount an anchor on the companionway hatch cover!

This has been proven to increase downwind speed every time, regardless
of mast
rake!


Actually, we open our cabintop hatch and our bow hatch straight up, to
grab more wind while going downwind.


Do you make the crew stand up too? We do that in NZ.

And block the sails? That doesn't sound too bright.





This signature is now the ultimate power in the universe

Mast Rake and Mast Bend
 

On big boats the crew are below sails.

Cheers MC

Horvath wrote:

On Thu, 15 Jan 2004 14:44:41 +1300, MC wrote this
crap:



Horvath wrote:


On Wed, 14 Jan 2004 11:18:40 -0500, DSK wrote
this crap:



Now explain to us exactly how increased rake causes a deterioration in
downwind performance and what can be done to offset this, (without removing
the rake). No google.


I know, I know!! Mount an anchor on the companionway hatch cover!

This has been proven to increase downwind speed every time, regardless of mast
rake!


Actually, we open our cabintop hatch and our bow hatch straight up, to
grab more wind while going downwind.


Do you make the crew stand up too? We do that in NZ.


And block the sails? That doesn't sound too bright.





This signature is now the ultimate power in the universe

Mast Rake and Mast Bend
 

DSK wrote:

"MC" wrote...

You know where the mast goes through the deck? Is it fixed in the metal
ring perhaps with a big bolt?


Have you seen many keelboats with masts fixed by a thru-bolt at the partners?
This is not a very common arrangement at all over here. In fact I haven't ever
seen one.



Well it is seen in offshore boats. It serves to lock the deck to the
mast to make the deck stronger as well as ensuring the parner seal
doesn't work when the mast pumps.


...It's just that if you were interested in
altering rake my adjustments at deck level it would be impossible with a
bolted partner... Instead you would have to alter rake at the mast foot
and that is also impossible on many boats as the foot casing is welded
or bonded to a ring frame.

Donal wrote:
I think that there are wooden chocks holding it in a vertical position.

Underneath the mast, there is a metal plate (SS or ally??) with two vertical
plates welded to it. These verticals are either side of the mast, and a
bolt goes through the lot.


Donal it apears that if you were interested in changing the rake of your mast,
or perhaps even shifting the whole mast a little bit forward or aft, it would be
possible (as it is on most properly rigged boats). A little work at the chocks
and/or at the step. However you've always said that your boat sails well, please
don't think I am advocating this.

One thing to take a close look at, before such an undertaking, is what the
structural grid under the mast step is like. Usually (in a properly designed and
built boat) there is allowance for the mast butt to be moved a couple inches,
maybe less, each way; and there is sufficient structural strength to support it.

It seems that MC has never tuned a keelboat and isn't sure how masts are
adjusted; or it may be that his own much-bragged-about has it's mast fixed
rather oddly... perhaps the riggers did it on purpose so that he couldn't mess
it up?



Aw, you really should try to get your jealousy under control. In fact I
altered the rig last year when my new contender racing sails were made.

Cheers