I am looking into the HSM Superfreak 8.0 sail for my Bic WindSup. On the HSM Forum they say the sail goes with a flextop mast, but I have a c.c. Gun Sails Mast 75% carbon. Can I rig the Superfreak on it, without appreciable draw-backs? What are the drawbacks, if any?

I am a run-of-the-mill windsurfer, with a few years experience, but I'm neither an advanced sailor nor a speed-buff nor adrenaline looking sailor. My performance expectations do not go beyond cruising and possibly planing in moderate winds. My criteria in choosing equipment are therefore not as stringent as those of other windsurfers.

All I want is to extend the wind range of my board, within the limits, of course, of the WindSup design, which is admittedly not a planing shortboard.

For some reasons I can't post my question on the HSM Forum, but then I think an independent Forum like yours is perhaps more reliable for obvious reasons, as there is no vested interest in selling.

Another alternative may be the sailworks Retro. It is also less expensive, but I like the Superfreak because it is Dacron-made, hence very light, in addition to other qualities I read about. Actually, I already have an old 6.2 N.P. Garda, also made of Dacron. A superb sail, just as good as any "modern" sail for my needs, even it is from the 90's !

Thanks

Francone

Advise if this Gun is a SDM..size I assume is 490?

1. I took the liberty of posting on the HSM forum, it's under the Freak section, if this is not acceptable I will remove it.

2. If the Gun is a SDM, I have found them MORE forgiving than a RDM, when the mast curve is close, so not ideal.I have used powerex SDM in my Superfreaks and they did work just peachy, I would say the curve is similar to the Gun, without actually knowing the mast bend numbers.

3. Jeff Henderson , the Superfreak designer will answer your personal Questions, I feel he will do this without bias towards , just selling you a mast and or sail.
hot@hotsailsmaui.com
it is his weekend as well right now, withe AWT/PWA Is there so a answer may take a few days.

line at the bottom...
the Gun IMO, is not ideal, but I don't feel it off the mark so far . It would suit the Retro. Looking at the level you are, by your description, the Gun should be fine on the HSM.

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forceten said..
Advise if this Gun is a SDM..size I assume is 490?

1. I took the liberty of posting on the HSM forum, it's under the Freak section, if this is not acceptable I will remove it.

2. If the Gun is a SDM, I have found them MORE forgiving than a RDM, when the mast curve is close, so not ideal.I have used powerex SDM in my Superfreaks and they did work just peachy, I would say the curve is similar to the Gun, without actually knowing the mast bend numbers.

3. Jeff Henderson , the Superfreak designer will answer your personal Questions, I feel he will do this without bias towards , just selling you a mast and or sail.
hot@hotsailsmaui.com
it is his weekend as well right now, withe AWT/PWA Is there so a answer may take a few days.

line at the bottom...
the Gun IMO, is not ideal, but I don't feel it off the mark so far . It would suit the Retro. Looking at the level you are, by your description, the Gun should be fine on the HSM.

Thanks for forwarding my query to HSM. It is there now. Waiting for an answer, but I still cannot login..
Anyway, my Gun Sails mast is SDM, 75% carbon. It is 460 cm , but I think I can safely rig the Superfreak 8.0 on it( 507 cm luff) by using a 20 cm tip extension and a mast base extension of 40 cm.
I know, some do not recommend mast tip extensions, but I wouldn't buy a new mast.

I think a short tip extension won't either substantially affect the bending properties or, worse, break the mast. The extension is in aluminium, only 20 cm long. Too short to cause problems, I believe.

I could perhaps go down to the 7.0 size and use the 460 mast, but I'd prefer an 8.0 for more power, also because of my weight ( 85 kg ).

Until recently, I wouldn't have thought of using an 8.0 : I used to have an 8.5 Severne Focus which I found a bit uncomfortable: very heavy in light winds and even heavier to uphaul. I hardly ever used it and I sold it.

Now that I started using ( belatedly!) the harness and that I bought a superstable board like the Bic WindSup, I hardly fall and I can tackle higher winds. Now I regret having sold the Severne. It was also a very light sail ( for its size, especially if compared to the otherwise excellent Ezzies. Their Freeride was heavier!) .So an 8.0 should be O.K. now.

Francone

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Francone said..

forceten said..
Advise if this Gun is a SDM..size I assume is 490?

1. I took the liberty of posting on the HSM forum, it's under the Freak section, if this is not acceptable I will remove it.

2.

3. Jeff Henderson , the Superfreak designer will answer your personal Questions, I feel he will do this without bias towards , just selling you a mast and or sail.
hot@hotsailsmaui.com
it is his weekend as well right now, withe AWT/PWA Is there so a answer may take a few days.


Forceten,

did you by any chance remove my post that you had kindly forwarded to HSM ? I wouldn't think so, but it it was there the first time I looked at it and it is no longer there now. Besides, I can't even log in, even though I registered. They say the PW is wrong, but I'm sure it is the right one. Anyway, this is not your problem, I guess.

Francone

Firstly HSM sails are not specified for flexi top masts that is NP although there RDM masts seem to have a little less flex.

All masts basically are constant curve just some are built with more or less flex in the top and it seems more and more companies are moving to the middle.

refer to unifiber mast selector www.unifiber.net/masts-selector

HSM use constant curve mast with a little bit of extra flex in the top.

You can rig a HSM sail with a Gun Sails constant curve mast it will just not lay off so much which some heavy weight sailors might like as it will spill less wind some light weight sailors might not like it, Most will not be able to tell the difference.

Now rigging a HSM sail with an Avanti or point seven mast is going to be a problem as there is just not enough flex in the top for the sail to rig nicely.

Select to expand quote

legless said..
Firstly HSM sails are not specified for flexi top masts that is NP although there RDM masts seem to have a little less flex.

All masts basically are constant curve just some are built with more or less flex in the top and it seems more and more companies are moving to the middle.

refer to unifiber mast selector www.unifiber.net/masts-selector

HSM use constant curve mast with a little bit of extra flex in the top.

You can rig a HSM sail with a Gun Sails constant curve mast it will just not lay off so much which some heavy weight sailors might like as it will spill less wind some light weight sailors might not like it, Most will not be able to tell the difference.

Now rigging a HSM sail with an Avanti or point seven mast is going to be a problem as there is just not enough flex in the top for the sail to rig nicely.

Glad to hear that a c.c. mast will do with a HSM Superfreak, but on their Forum (Jeff Henderson, I believe) they explicitly say that this sail IS for flextops. Perhaps it was an old post and it is possible that something has changed in their design..

Thanks

Francone

Select to expand quote

legless said..
Firstly HSM sails are not specified for flexi top masts that is NP although there RDM masts seem to have a little less flex.

All masts basically are constant curve just some are built with more or less flex in the top and it seems more and more companies are moving to the middle.

refer to unifiber mast selector www.unifiber.net/masts-selector

HSM use constant curve mast with a little bit of extra flex in the top.

You can rig a HSM sail with a Gun Sails constant curve mast it will just not lay off so much which some heavy weight sailors might like as it will spill less wind some light weight sailors might not like it, Most will not be able to tell the difference.

Now rigging a HSM sail with an Avanti or point seven mast is going to be a problem as there is just not enough flex in the top for the sail to rig nicely.

www.peterman.dk/windsurf-mast-article-gb01.htm

This is is one of the better resource guides for mast bend characteristics.
using the testing method, in brief, hang a 30kg weight from the center of the horizontal mast, measure the mast deflection at 1/4 and 3/4, the amount is turned into a percentage, of the amount the mast deflects at 1/4 3/4 in relation to where the weight is hung, 1/2. The HSM HotRods, of which about 4 variations exist from 2006 are 65 lower 79 top, subtract those 2 , and the result is 14. This 14 now becomes the overall mast bend curve, (not stiffness.)
this number reflects more how the mast will perform under a load.
0--6. Hard top
7--9 hardtop constant curve (CC)
10--12 CC
13--15 CC Flextop
16--18 flextop
19--21 flextop super
22--superflex

The HotRod is 14. Using the UNIFIBER chart( which changes each year) the HSM masts are 3 dots to the right of Gun, clearly into flextop.
the number of dots going across are limited, and the initial line and last are not used at all, this increases the difference in interpretation greatly.
as well the above numeric chart , goes from 6--22 , hardly no masts are that stiff nor that flextop .

Since this question does not relate to Avanti, Point 7 or Neil Pryde, see no reason to include.
Point about mast sailmakers , designing around CC masts is correct, looking back at previous year UNIFIBER charts as they change hopefully so does the chart.

sail performance VS mast::
You can use any mast in any sail, it depends on how much range the sail has to begin with AND
how much you are willing to give up.

having had several experiences with mast/ sails that were not compatable, I found out that the more I learned the more I found I had yet to learn, still do.

Select to expand quote

forceten said..

legless said..
Firstly HSM sails are not specified for flexi top masts that is NP although there RDM masts seem to have a little less flex.

All masts basically are constant curve just some are built with more or less flex in the top and it seems more and more companies are moving to the middle.

refer to unifiber mast selector www.unifiber.net/masts-selector

HSM use constant curve mast with a little bit of extra flex in the top.

You can rig a HSM sail with a Gun Sails constant curve mast it will just not lay off so much which some heavy weight sailors might like as it will spill less wind some light weight sailors might not like it, Most will not be able to tell the difference.

Now rigging a HSM sail with an Avanti or point seven mast is going to be a problem as there is just not enough flex in the top for the sail to rig nicely.

www.peterman.dk/windsurf-mast-article-gb01.htm

This is is one of the better resource guides for mast bend characteristics.
using the testing method, in brief, hang a 30kg weight from the center of the horizontal mast, measure the mast deflection at 1/4 and 3/4, the amount is turned into a percentage, of the amount the mast deflects at 1/4 3/4 in relation to where the weight is hung, 1/2. The HSM HotRods, of which about 4 variations exist from 2006 are 65 lower 79 top, subtract those 2 , and the result is 14. This 14 now becomes the overall mast bend curve, (not stiffness.)
this number reflects more how the mast will perform under a load.
0--6. Hard top
7--9 hardtop constant curve (CC)
10--12 CC
13--15 CC Flextop
16--18 flextop
19--21 flextop super
22--superflex

The HotRod is 14. Using the UNIFIBER chart( which changes each year) the HSM masts are 3 dots to the right of Gun, clearly into flextop.
the number of dots going across are limited, and the initial line and last are not used at all, this increases the difference in interpretation greatly.
as well the above numeric chart , goes from 6--22 , hardly no masts are that stiff nor that flextop .

Since this question does not relate to Avanti, Point 7 or Neil Pryde, see no reason to include.
Point about mast sailmakers , designing around CC masts is correct, looking back at previous year UNIFIBER charts as they change hopefully so does the chart.

sail performance VS mast::
You can use any mast in any sail, it depends on how much range the sail has to begin with AND
how much you are willing to give up.

having had several experiences with mast/ sails that were not compatable, I found out that the more I learned the more I found I had yet to learn, still do.

According to your break down if the HSM Hot rod is 14 it is classed as CC flextop....not flex top as I was saying

As for the HSM sails mast being 3 steps away from the Gun sails mast that is not correct its 3 steps carry on from where the gun sails steps end so at best it is 1 step away and at worst it is 3.

I used to sell HSM gear and I have ordered mast from a mast manufacturer for a specific bend curve to suit HSM sails so I have a pretty good understanding on bend curve. I have also been windsurfing over 30 years so have tried many sail and mast combinations.

The problem is it is easier to say hardtop, constant curve or flextop but each covers a wide range of flex and calling a HSM flex top mast is not specific enough.

I have used a 460 mast with the SF 8M using the longest Chinook carbon RDM extension, I did not need a mast tip extension. 490 works better of course. My masts are the old Kilwell Hot Sails masts made in New Zealand.

""""As for the HSM sails mast being 3 steps away from the Gun sails mast that is not correct its 3 steps carry on from where the gun sails steps end so at best it is 1 step away and at worst it is 3."""


for the HSM , on the chart to be aligned with GUN, all 3 of theHSM DOTS, would need to be moved to the left, moving 1 left would continue having 1 in the CC FLEXTOP column.


""""The problem is it is easier to say hardtop, constant curve or flextop but each covers a wide range of flex and calling a HSM flex top mast is not specific enough.""""

Yes, that's why a CC flextop category exist, and was pointed out.



your years of experience I m sure serves you well

I am more worried about extension that is pretty much max AND a tip extension, neither of which bend. I can't see it working well at all.

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Mark _australia said..
I am more worried about extension that is pretty much max AND a tip extension, neither of which bend. I can't see it working well at all.

Glad you pointed this out , as the original post did not include this.
he is looking at, however, not a proper mast extension, I Think , but a extendo , which is a carbon 40cm section , looking like a mast section.

I find no fault on this, still use one on a sail , (long story) its 2000 mile away, and I use it only a few times a year, basically it raises the mast length at the bottom by 40cm, in this case it could actually make thing better, COULD.., the tip I think like, can't see it working.

You can look at all the numbers and charts etc, but I've been rigging my HSM race sails on a CC mast for a couple of years and that works great for me. There's only a slight bias toward flex top, so a CC will be fine.

i have an HSM SpeedFreak 8.5
broke my NP 490 SDM mast and tried a Chinook CC mast - NO other 490 available @ Cape Hatteras, North Carolina = sucked
bought another NP mast and back in business - sold the Chinook
HSM IS FLEXTOP

and NO, Francone is NOT planning on using an extender at the bottom of the mast
wants to put mast extension @ 40 cm max AND an aluminum extension at the top
WHY bother talking about the flex of the mast in a case like that
asking for trouble in my book

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N1GEL said..
You can look at all the numbers and charts etc, but I've been rigging my HSM race sails on a CC mast for a couple of years and that works great for me. There's only a slight bias toward flex top, so a CC will be fine.

YMMV

the numbers and charts are what we have. Slight bias, being a relative term,where any bias could make some difference.

out of curisoty what CC mast and it's particulars are you using with your GPS?

Select to expand quote

joe windsurf said..
i have an HSM SpeedFreak 8.5
broke my NP 490 SDM mast and tried a Chinook CC mast - NO other 490 available @ Cape Hatteras, North Carolina = sucked
bought another NP mast and back in business - sold the Chinook
HSM IS FLEXTOP

and NO, Francone is NOT planning on using an extender at the bottom of the mast
wants to put mast extension @ 40 cm max AND an aluminum extension at the top
WHY bother talking about the flex of the mast in a case like that
asking for trouble in my book

I don't see where the extension is referred to.
In any case the constant is overall stiffness, the IMCS rating. A flex top mast is both softer in the top and stiffer in the bottom than a cc mast.
If you rig a flex top sail on a cc mast it will set flatter in the belly and tighter in the upper leach. If you add down haul to loosen the upper leach you flatten the belly even more. If you use an overextended short mast presumably it's overall stiffness is less too. In that case the belly would be flattened even more.
It's a recipe for a gutless sail.

^^ he said "Anyway, my Gun Sails mast is SDM, 75% carbon. It is 460 cm , but I think I can safely rig the Superfreak 8.0 on it( 507 cm luff) by using a 20 cm tip extension and a mast base extension of 40 cm. I know, some do not recommend mast tip extensions, but I wouldn't buy a new mast. "

I wouldn't be doing it...... but for non planing and really need that extra sail size, hmmm maybe..... but like you said gutless sail - so it may have the same power as a properly rigged smaller sail and that defeats the purpose.

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forceten said..

N1GEL said..
You can look at all the numbers and charts etc, but I've been rigging my HSM race sails on a CC mast for a couple of years and that works great for me. There's only a slight bias toward flex top, so a CC will be fine.

YMMV

the numbers and charts are what we have. Slight bias, being a relative term,where any bias could make some difference.

out of curisoty what CC mast and it's particulars are you using with your GPS?

Chinook 90% RDM. Rigs perfectly with a 6.0 and 6.6.

Also use a KA RDM 100% carbon mast with no problems at all. Can't tell the difference between the KA mast and my Chinook mast and my simmer masts. They all rig great on HSM sails.

So, make of this what you like, but in my experience, HSM rigs perfectly fine on a range of flexes from CC to flextop (unifiber chart). I've been using HSM sails exculsively for a couple of years now, ranging from 2013-2016 and they work great with a range of masts.

No disrespect to Joe, but perhaps you simply didn't rig it properly, mate. What exactly was the issue?

Gareth (legless) is on the money with his comments. He was the Australian HSM distributor for years, so if I was the OP I would listen to his advice that your mast will likely work.

Select to expand quote

NotWal said..

joe windsurf said..
i have an HSM SpeedFreak 8.5
broke my NP 490 SDM mast and tried a Chinook CC mast - NO other 490 available @ Cape Hatteras, North Carolina = sucked
bought another NP mast and back in business - sold the Chinook
HSM IS FLEXTOP

and NO, Francone is NOT planning on using an extender at the bottom of the mast
wants to put mast extension @ 40 cm max AND an aluminum extension at the top
WHY bother talking about the flex of the mast in a case like that
asking for trouble in my book

I don't see where the extension is referred to.
In any case the constant is overall stiffness, the IMCS rating. A flex top mast is both softer in the top and stiffer in the bottom than a cc mast.
If you rig a flex top sail on a cc mast it will set flatter in the belly and tighter in the upper leach. If you add down haul to loosen the upper leach you flatten the belly even more. If you use an overextended short mast presumably it's overall stiffness is less too. In that case the belly would be flattened even more.
It's a recipe for a gutless sail.

Joe must know the OP.
YOUR STATEMENT that a flex top will be softer on the top and stiffer on the bottom of a CC , is misleading at least.
This from a quick look
NP 64 79
Gun select 61.8. 78.5
the Gun is generally accepted as CC , yet the top is soft, the bottom is stiffer than the NP.
YOUR STATEMENT OR presumed one, about stiffness is incorrect.

All masts keep their mast bend curve (approx) when extended.
all masts become a little stiffer, using the IMCS standard when extended.
the percentage of a little stiffer will vary from 2 on a stifftop , 3-6 on a CC , and 6-7 for flex top.

YOUR STATEMENT ON RIGGING IS opposite , to begin with a CC and flex top won't ( total generalization as too many variations exist) have a wide view of in- compatibility, it may not sail great, but won't look terrible. using a CC Mast on a flextop sail, will produce depth or profile in the bottom, and middle, the top loose. The transition between the bottom and top , will be sudden with wrinkles. It should all be noticeable but not extreme.

Stiffness of the mast IMCS, tells us something about at what load the mast starts working. The bend curve tells something about how the mast works when loaded. The numbers at times are very misleading, using just IMCS , is about useless.

Surf Magazine, Germany : Boards UK , have done lots of mast tests, along with the peterman mast article, these theories come from their findings.

Why we're on the subject of masts, I have a question? I am going to try my new Ezzy mast set up by using a Ezzy Hookipa 400 bottom and Ezzy Hookipa 460 top to make a 430 mast. Is this set up going to be more stiffer or Bendier than a traditional Ezzy Hookipa 430 set-up? Or in other words is my set-up going to be more flextop, CC, or hardtop?

A li

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Magic Ride said..
Why we're on the subject of masts, I have a question? I am going to try my new Ezzy mast set up by using a Ezzy Hookipa 400 bottom and Ezzy Hookipa 460 top to make a 430 mast. Is this set up going to be more stiffer or Bendier than a traditional Ezzy Hookipa 430 set-up? Or in other words is my set-up going to be more flextop, CC, or hardtop?

compared to a pure 430 mast (430top~430btm) - it will be a touch stiffer at the top and a touch softer in the middle and bottom.

I use this combo for a KA Koncept 6.6, the rotation of the bottom cam is so much better and haven't lost any of my tune~ability at the top.

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DavMen said..
A li

Magic Ride said..
Why we're on the subject of masts, I have a question? I am going to try my new Ezzy mast set up by using a Ezzy Hookipa 400 bottom and Ezzy Hookipa 460 top to make a 430 mast. Is this set up going to be more stiffer or Bendier than a traditional Ezzy Hookipa 430 set-up? Or in other words is my set-up going to be more flextop, CC, or hardtop?

compared to a pure 430 mast (430top~430btm) - it will be a touch stiffer at the top and a touch softer in the middle and bottom.

I use this combo for a KA Koncept 6.6, the rotation of the bottom cam is so much better and haven't lost any of my tune~ability at the top.

Reading DavMen , i believe his opinion is correct, this on the question asked which regards Ezzy. Who have an extensive combo mast practice, using the shorter bottom and longer top.

since the thread is about HSM, and or Gun, Hot Sails combo advocate the opposite , longer bottom, shorter top, makes sense to keep the top soft.

i feem some explationtion , is needed from me.
My use of CAPS, in posts has been in no way rude or discourteous in my POV. I have used it to emphasize a point, in future I will refrain from its use.
i apologize to any any all that may have taken my intent otherwise. Done , point taken!

it would seem that some have taken my mast discussion to say that I'm opposed to the Gun mast, kindly reread my first, and the first reply to the OP.

i feel the same now that it would be ok, not ideal. However additional information is now available, in that the OP , wants to use a mast tip extension.
This along with a long mast base extension . This moves the Gun mast some further away From ideal.

Select to expand quote

forceten said..

NotWal said..
...

I don't see where the extension is referred to.
In any case the constant is overall stiffness, the IMCS rating. A flex top mast is both softer in the top and stiffer in the bottom than a cc mast.
If you rig a flex top sail on a cc mast it will set flatter in the belly and tighter in the upper leach. If you add down haul to loosen the upper leach you flatten the belly even more. If you use an overextended short mast presumably it's overall stiffness is less too. In that case the belly would be flattened even more.
It's a recipe for a gutless sail.

Joe must know the OP.
YOUR STATEMENT that a flex top will be softer on the top and stiffer on the bottom of a CC , is misleading at least.
This from a quick look
NP 64 79
Gun select 61.8. 78.5
the Gun is generally accepted as CC , yet the top is soft, the bottom is stiffer than the NP.
YOUR STATEMENT OR presumed one, about stiffness is incorrect.

All masts keep their mast bend curve (approx) when extended.
all masts become a little stiffer, using the IMCS standard when extended.
the percentage of a little stiffer will vary from 2 on a stifftop , 3-6 on a CC , and 6-7 for flex top.

YOUR STATEMENT ON RIGGING IS opposite , to begin with a CC and flex top won't ( total generalization as too many variations exist) have a wide view of in- compatibility, it may not sail great, but won't look terrible. using a CC Mast on a flextop sail, will produce depth or profile in the bottom, and middle, the top loose. The transition between the bottom and top , will be sudden with wrinkles. It should all be noticeable but not extreme.

Stiffness of the mast IMCS, tells us something about at what load the mast starts working. The bend curve tells something about how the mast works when loaded. The numbers at times are very misleading, using just IMCS , is about useless.

Surf Magazine, Germany : Boards UK , have done lots of mast tests, along with the peterman mast article, these theories come from their findings.

I'm not sure if were talking across purposes but some of what you say is wrong.

A flex top mast is softer in the top and stiffer in the bottom than a constant curve for masts of the same length and stiffness.
This is straight forward mechanics.
When you measure a masts stiffness you measure the overall deflection at the middle of the mast under a given load, 30kg in the MCS and IMCS tests.
If the deflection in the top is high as for a flex top then the deflection in the bottom must be low if the overall deflection is the same and it's the overall deflection that defines stiffness.
I don't know how those numbers for the NP and Gun masts argue for you. They are both flex tops. The discrepancy in the bottoms implies a different overall stiffness or an error.

A stiff mast bottom produces more fullness. A soft bottom produces a flatter belly.
If you doubt it you can test it by rigging the same sail on different length/stiffness masts.

As for extending a mast making it stiffer according to IMCS measurement it may be slightly stiffer than the mast that is extended but it is softer than the longer mast it replaces. Is that not what you say?

Rather than post quote upon quote this from N1gel,

""""Chinook 90% RDM. Rigs perfectly with a 6.0 and 6.6. Also use a KA RDM 100% carbon mast with no problems at all. Can't tell the difference between the KA mast and my Chinook mast and my simmer masts. They all rig great on HSM sails. So, make of this what you like, but in my experience, HSM rigs perfectly fine on a range of flexes from CC to flextop (unifiber chart). I've been using HSM sails exculsively for a couple of years now, ranging from 2013-2016 and they work great with a range of masts. No disrespect to Joe, but perhaps you simply didn't rig it properly, mate. What exactly was the issue? Gareth (legless) is on the money with his comments. He was the Australian HSM distributor for years, so if I was the OP I would listen to his advice that your mast will likely work.""""

Chinook being a American company are well known, the masts are made in Europe, central southern , country unknown. They have been and are CC suspect in HSM and "most" sails would work fine..
KA, I can offer no info, nor find what the mast curve is .

feel our opinions on Gun masts , are fairly consistent , in that it will work fine, given the original post information, later statement of a mast tip extension , of even 10cm , puts things into a different perspective.

my discussion with legless, has to do with his VS my interpretation of the Unifiber chart, what the dots mean and where they are.

as a distributor, former , he should have a wealth of knowledge to share And look forward to his posts.

Select to expand quote

forceten said..
Rather than post quote upon quote this from N1gel,

""""Chinook 90% RDM. Rigs perfectly with a 6.0 and 6.6. Also use a KA RDM 100% carbon mast with no problems at all. Can't tell the difference between the KA mast and my Chinook mast and my simmer masts. They all rig great on HSM sails. So, make of this what you like, but in my experience, HSM rigs perfectly fine on a range of flexes from CC to flextop (unifiber chart). I've been using HSM sails exculsively for a couple of years now, ranging from 2013-2016 and they work great with a range of masts. No disrespect to Joe, but perhaps you simply didn't rig it properly, mate. What exactly was the issue? Gareth (legless) is on the money with his comments. He was the Australian HSM distributor for years, so if I was the OP I would listen to his advice that your mast will likely work.""""

Chinook being a American company are well known, the masts are made in Europe, central southern , country unknown. They have been and are CC suspect in HSM and "most" sails would work fine..
KA, I can offer no info, nor find what the mast curve is .

feel our opinions on Gun masts , are fairly consistent , in that it will work fine, given the original post information, later statement of a mast tip extension , of even 10cm , puts things into a different perspective.

my discussion with legless, has to do with his VS my interpretation of the Unifiber chart, what the dots mean and where they are.

as a distributor, former , he should have a wealth of knowledge to share And look forward to his posts.

Select to expand quote

NotWal said..

forceten said..

NotWal said..
...

I don't see where the extension is referred to.
In any case the constant is overall stiffness, the IMCS rating. A flex top mast is both softer in the top and stiffer in the bottom than a cc mast.
If you rig a flex top sail on a cc mast it will set flatter in the belly and tighter in the upper leach. If you add down haul to loosen the upper leach you flatten the belly even more. If you use an overextended short mast presumably it's overall stiffness is less too. In that case the belly would be flattened even more.
It's a recipe for a gutless sail.

Joe must know the OP.
YOUR STATEMENT that a flex top will be softer on the top and stiffer on the bottom of a CC , is misleading at least.
This from a quick look
NP 64 79
Gun select 61.8. 78.5
the Gun is generally accepted as CC , yet the top is soft, the bottom is stiffer than the NP.
YOUR STATEMENT OR presumed one, about stiffness is incorrect.

All masts keep their mast bend curve (approx) when extended.
all masts become a little stiffer, using the IMCS standard when extended.
the percentage of a little stiffer will vary from 2 on a stifftop , 3-6 on a CC , and 6-7 for flex top.

YOUR STATEMENT ON RIGGING IS opposite , to begin with a CC and flex top won't ( total generalization as too many variations exist) have a wide view of in- compatibility, it may not sail great, but won't look terrible. using a CC Mast on a flextop sail, will produce depth or profile in the bottom, and middle, the top loose. The transition between the bottom and top , will be sudden with wrinkles. It should all be noticeable but not extreme.

Stiffness of the mast IMCS, tells us something about at what load the mast starts working. The bend curve tells something about how the mast works when loaded. The numbers at times are very misleading, using just IMCS , is about useless.

Surf Magazine, Germany : Boards UK , have done lots of mast tests, along with the peterman mast article, these theories come from their findings.

I'm not sure if were talking across purposes but some of what you say is wrong.

A flex top mast is softer in the top and stiffer in the bottom than a constant curve for masts of the same length and stiffness.
This is straight forward mechanics.
When you measure a masts stiffness you measure the overall deflection at the middle of the mast under a given load, 30kg in the MCS and IMCS tests.
If the deflection in the top is high as for a flex top then the deflection in the bottom must be low if the overall deflection is the same and it's the overall deflection that defines stiffness.
I don't know how those numbers for the NP and Gun masts argue for you. They are both flex tops. The discrepancy in the bottoms implies a different overall stiffness or an error.

A stiff mast bottom produces more fullness. A soft bottom produces a flatter belly.
If you doubt it you can test it by rigging the same sail on different length/stiffness masts.

As for extending a mast making it stiffer according to IMCS measurement it may be slightly stiffer than the mast that is extended but it is softer than the longer mast it replaces. Is that not what you say?

Perhaps it is some cross talk.
the figures I'm using are from several magazines, the results placed in the peterman , mast discussion. If you take exception to them, so be it.
Your discussion on stiffness is correct, IMCS is the mast deflection of the entire mast, length wise, to compare the same size must be used.the larger the number the stiffer it is. So imprinted IMCS 32, this refers to its overall stiffness. So far I think we are on the same page.
The IMCS number is one of the measures, mast bend curve the other. Already discussed how it's arrived.
example
Neil Pryde X9, 460, IMCS 25.1

Severne Red , 460, IMCS 25.2
according to that the overall stiffness is near the same. These numbers are real.

The bend curve tells much more.
NP. ... 63/78
Severne..63/73

Using the latter... the NP is 14.3 very typical for NP, actually a little stiff
"..............the Severne is 11.4 which is somewhat typical , it's a little soft

the last question in your post..extending, by extending 30cm , to reach the length of the next longer mast, yes it will be softer, depending on the curve, hard, soft the percentage will vary from 1/6 to 3/4 of the required stiffness to reach the next longer mast.

numbers in relation to many aspects in windsurfing, don't alway colate.
except
board$2000
sail $500
mast $350
__________
$2850

so..... an 8.0m2 HSM SF on a windsup using a 20 cm tip extension and a mast base extension of 40 cm on a 460 mast to suit a 507 luff because an 8.5m3 severn focus was no good ...

and....

you'se all arguing about the stiffness of the mast ?

Hahaha nice summary

The tally i count is
3 say yes to the Gun
3 say no*

* That count could be pretty near 6 no, if addressed to the mast tip extension.

opinions on the HotSail forum, are , 2 no , or lean heavily that way, with concern the Gun is not a flex top.

i don't like the mast tip at all, I have seen it done and said with good results, on a newly purchased sail, just to make the correct length , I would not.

my longest mast extension is 48cm, in a SDM, if I were inclined , I would use it to the max to achieve the length necessary.
i think I would not be inclined. A 7.0 ..may be too small , rigging on a 460

Select to expand quote

Beaglebuddy said..
I have used a 460 mast with the SF 8M using the longest Chinook carbon RDM extension, I did not need a mast tip extension. 490 works better of course. My masts are the old Kilwell Hot Sails masts made in New Zealand.

Talking about mast tip extensions! I have an old N.P. Garda 6.2 with a 490 cm luff, which I have always used with my 460 mast ( Gun Sails).
Today I rigged the Garda on the yard, to try a new mast tip extension I just made. This extension is 17 cm long.
To my surprise, on the same 460 cm mast the sail rotates much much better with the tip extension ! I suppose it is because the sail now sits 17 cm higher up, where the mast is less thick. Not much, but sufficient to make the luff sleeve is looser hence loosen up the battens. ..

On the other hand, on one occasion I had tried to rig a more recent sail ( a Severne Focus 8.5, with practically the same luff , 495 cm ) on a 490 cm mast and it didn't work: the 490 mast didn't seem to bend as easily as the 460 with the same sail and the d/haul was harder, too. I assume it is because the bending coefficients are distributed differently on a 460 mast as compared to a shorter 460.

Maybe somebody can comment on this.

Ittiandro