What is the story about hard top masts

Yes Maui became much less hard top.

But I know what you are thinking, and no you can't stick a Maui mast in your sail to increase leech tension. The rest of the curve will be wrong and with cambered sail that will be fatal.
(I still don't see how an 8.5 does not get you going on a longboard )

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Francone said..
Hi!
Does anybody know if Maui still make hardtop masts? Traditionally, I have always known that Maui, Gaastra, Naish and Severne were among the main hardtop masts manufacturers, but the 2014 Unifiber site, as well as some people in other forums, seem to think otherwise. In fact , according to the Unifiber 2014 chart, Maui and Naish are now into c.c. , Gaastra is borderline with c.c. and most of the other hardtop manufacturers are hardtop only in the RDM category. Even Severne, in the SDM category seems to be borderline with c.c. To complicate things even further, now some people in other forums state that Maui has gone into c.c. since last year.
I am still waiting for an answer from Maui. Confusing, isn’it? I don’t know anything about RDM . Advantages, disadvantages?
Somebody speaks of a general trend away from hardtops towards constant curve. Why, I don't know. May be somebody can comment on all this.
The reason why I was thinking of hardtop masts is that they may be better in light winds, because the relative stiffness of the top maintains a tighter leech, while the bottom part, more flexible, allows rotation even with a small DH. I sail mostly in very light winds and my c.c. mast does not allow my sails to have the tight leech I need for REALLY light winds subplaning.( 12 knts approx)

Thanks

Francone

are you in a harness yet? I can get planing on a 150 litre board with a 5.3 metre sail in about 16 kts...so as per Mark's comment above how are you not planing with the 8.5?

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Mark _australia said..
Yes Maui became much less hard top.

But I know what you are thinking, and no you can't stick a Maui mast in your sail to increase leech tension. The rest of the curve will be wrong and with cambered sail that will be fatal.
(I still don't see how an 8.5 does not get you going on a longboard )

I cannot argue against facts, i.e. that some people can happily sail with an 8.5 in light winds on a longboard. Perhaps weighing 65 kg instead of 82 also makes a difference or the winds are really too light, or the sail is not properly tuned or maybe it is a question of wrong technique on my behalf. I'll look into all this again next summer, because for the moment my lake is still under two feet of ice.
I don't quite understand though what you mean by the curve being wrong. With a Hard Top and the ensuing tighter leech, the curve will certainly shift. Most likely there will be a power transfer from bottom to the top of the sail. It may well be a wrong curve , but from which perspective? I gather it is more from the perspective of " normal" sailors, probably the majority, who sail ( or plane!) in stronger winds and must therefore be able to keep the lower power in the sail and a relatively strong DH against gusts and overpowering conditions.
In my case, this shifted curve, far from being wrong, may in fact be beneficial, because the tighter leech made possible by the H.T. mast may maximise the already light wind and give me that incremental power needed to move the board to a subplane faster.

As stated elsewhere in this forum, old longboards, ideally suited for subplaning, could subplane in the same light winds and with far smaller sails than we use today for shortboarding in the same conditions. And the leech was also tighter, far tighter ( in fact, with those old, stiff masts , either fiberglas or aluminum, you couldn't have a tighter leech! ) yet move they did ! May be there is a positive correlation between the " wrong" tighter leech, getting more power from the sail in light winds and being able to use a smaller sail.
So why do we worry about " wrong curves" from a tight leech? It is not a rhetorical question and I do not want to dismiss the " wrong curve" idea. I may be missing something, but I'd like to understand better where this idea of " wrong curve" comes from and its real impact on light winds sailors like myself..

Thanks

Francone

Ive had several naish masts not hard top, maybe quite old ones. Every single hard top mast ive seen & had snap has broken in exactly same spot- about halfway between boom & ferule, my thinking was harder top stiffened flex until it gets to a point where it has to flex & possibly fatigues or loads that point. Dont know if this is actual or not but i'll not use a hard top mast.

Alot of people can benefit by not going hard top in their sail as most people arent the size/weight/strength of pwa riders.

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Carantoc said..
Maybe I see am too simple but ...

If you are not planning then what real difference will a tighter leech make ?
The more load the more twist, if you have very little load then there is very little twist.

Yes, respectfully, I do think so! I also think you are looking at this issue on reverse: if winds are strong enough for planing and the DH is set properly, with a relatively loose leech, then and only then would you be right in saying that increasing the leech tension won’t make a difference, because you already have all the wind power you need and increasing the leech may perhaps destabilize you a bit, at worse.. !

On the other hand, if I am trying to sail in marginal wind conditions,not being able to harness the light wind as efficiently as possible, by tightening the leech a little( or considerably) more , just because the sail/mast design won't allow it ( and we all know why!), can and does ( from my own experience) make a HUGE difference : the difference between a healthy sub-planing and schlogging sideways or at best not moving. Of course my assumption is that the leech tension is just as important in the control of power as the outhaul, much like the accelerator is in a car.

When I got rid of my longboard a few years back, in order to enter the new and ( supposedly) blissful world of shortboards and planing, I probably made a mistake, because I did not take into account that we are not on the Ocean here , certainly not in Australia (!). Around here winds are not really strong most of the time ( or when they are, the lake is under two feet of ice..).
You may ironize as much as you want about sailing with an old bedsheet and a bamboo cane, but the fact is that subplaning was much, much easier then , than it is today for all our modern gear, unless you rig ridiculously large sails in light winds or bought expensive formula boards or top racing equipment or if you are a 150 lbs youth ( which can make a LOT of difference!).

Indeed, longboard sails were smaller and their tighter leech and relative lack of twist , far from being an obstacle to good sailing, were the very conditions which made it possible... Subplaning with them was just as good as with todays'modern gear ( except for planing) and sailing certainly was a far cry from a bedsheet on a bamboo cane! (But I like the image.Very creative! Actually, I did it here in Canada during a canoe trip in the wilderness and, with a lively wind, the canoe was almost planing !)

Most of the time progress is a real improvement, but sometimes it is really just a change, neither for the better nor for the worse..
Unless we let ourselves fall prey to fads, common places and the inevitable marketing spin of manufacturers, which shape our tastes, I don’t see any reasons why full speed planing should be necessarily better or more ” in” or less" nerdy" than subplaning, to the point of being compared to primitive sailing with a bedsheet and a bamboo pole....
This argument is from the perspective of the run-of-the-mill speed-oriented modern windsurfer. It is a good perspective, if it suits one's personal style, but not the only one and not the only right one.
It is all a question of taste. I might add that when discussing technical points, everybody, us included, would benefit from a better understanding of the physics and hydrodynamics behind windsurfing.. They are certainly more credible than, sometimes, all the talk out there in the..field..Maybe if there are engineers or designers among the readers, they are welcome to throw in their ideas.

But it is a very good discussion! Thank you for your input!

Francone

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Francone said..

Mark _australia said..

Francone said..

Mark _australia said..
Yes Maui became much less hard top.

But I know what you are thinking, and no you can't stick a Maui mast in your sail to increase leech tension. The rest of the curve will be wrong and with cambered sail that will be fatal.
(I still don't see how an 8.5 does not get you going on a longboard )

So why do we worry about " wrong curves" from a tight leech? It is not a rhetorical question and I do not want to dismiss the " wrong curve" idea. I may be missing something, but I'd like to understand better where this idea of " wrong curve" comes from and its real impact on light winds sailors like myself..

Thanks

Francone

The reason we worry about wrong curves is the same as your last thread where your sail did not work with 5cm or so less downhaul.

Hard top does not mean all the mast is the same, and then the top little bit is stiffer.

Firstly the diameter is likely to be different at some places. Then, if the curve is slightly different also, your cambers will have too much, or too little, pressure from the battens. So it won't rotate right, or cams will fall off when rigging etc etc. You MAY get away with it, but in attempt to make your leech tighter you will create other problems. It will feel like crap, maybe a tighter leech but everything else stuffed up.

Like in your other threads, people are basically saying use the sail as intended, you can't change things.

You may get benefit from using a modern sail designed for longboards (less twist and more bottom end) but you won't be able to 'make one yourself' by putting the wrong mast in your race rail.

Oh, I see what you mean by curve! It is the mast curve. I thought you were speaking of the curve as the profile of the sail!
Yes, I realize that a hardtop mast, not having the same diameter everywhere, may be more liable to breaking in certain points and also interfere with the cams.
For one thing, though, my sails are no cam. Also the idea of using a sail designed for longboards makes sense.
On the other hand, I am a person who likes to experiment and sometimes my curiosity overrides the fear of breaking equipment and throwing money away. Actually, I have already submitted to this Forum, I believe, the " wild" idea to modify one of my sails for a tighter leech by cutting two of the central batten in order to allow rotation of the sail , in spite of a slightly tighter leech than the sail would normally allow.
As expected I got some stern warnings about this, but I contacted the owner/designer of the company manufacturing the sail. He said that in principle he wouldn't recommend it, but, to my surprise neither was he totally against it. In fact he gave me very precise instructions about how to do it! If he doesn't know better, who would? This is to say that sometimes " conventional" wisdom can be tempered with a bit of creativity.

Thgank you for your input

Francone

Hi Francone

I think I understand what you are after, I have heard it referred to as the "glide" whereby you get into a nice little groove and glide along effortlessly.

A good longboard or WOD with a well tuned light wind sail with a deep draft and tight leech will make a huge difference to the experience for sure. I think your wasting your time trying to modify a sail that was designed for different conditions. I have both a 9.5 raceboard and 9.6 formula both Severne.The formula feels like a limp rag in light conditions whereas the raceboard feels powerful and efficient. Wind comes up and the table turns, formula feels powerful and stable and fast whereas the raceboard quickly feels uncomfortable and unstable and slow. Trying to tune the sails to perform in conditions they are not designed for has limited results.

Regarding sail size, big sails need not be difficult or cumbersome in light wind in fact the opposite. The most efficient way to sail in light winds is to get your weight off your feet and get it transferred though the mast foot via the rig ie harness lines, this will rail the board easier and keep the rig upright, therefore you are not holding the rig up it is holding you up. A bigger sail will make gybes and tacks easier and faster because the extra boom length and power of the rig will move the centre of effort further forward or aft and the power will drive it faster. Uphauling is simply technique in fact a big sail can be uphauled easily without an uphaul rope simply by positioning it correctly in relation to the wind and board. Much like a water start use the wind to help lift it rather than fight the wind. Also you tend to drop the sail far less in light conditions on a bigger volume board.


I know lightweight guys who opt for 8.5 over 9.5 because the wind range of the sail is greater for them and the difference in performance in lightwind is small given their weight.
In short to get what you want get a lightwind raceboard sail. The reason they make them bigger now than they used to is because that is better in every aspect for lightwind sailing.

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terminal said..
I have a mixture of Gaastra and one Naish hard top sails and now use Gaastra masts with all of them. I find the Gaastra masts to be slightly less hard-top, so I can use the 430 RDM with the 5.0 Naish and it works well, or I can use the 400RDM if the wind is strong and very gusty.

The impression I get is that these sails have a smaller wind range (less top end) but have a good low end for their size. You can see in this video that there is little softness in the top of the sail. I reckon instead of softness in the sail, the mast bends more from lower down above the boom and instead of using slackness in the sail, they use the mast twisting off from the boom up to spill the excess wind. Just my opinion.

Great video! Surprising how stiff is the top of your sail for this type of winds. Normally people give a strong DH and you see the top twisting a lot more. This is another point in favor of he H.T., even though concerns have been raised in other regards. Some people say that the uneven distribution of the bending curve along the H.T. masts ( different thicknesses) may result in weaknesses which break the mast.
Today I have been doing some experiments ( modifications) on a sail which somebody gave me but I hardly ever used because it is too small for my usual wind range. It is an old cammed Sailworks Race 5.6. It is a Flextop 22-27 IMCS. First, I removed the cams because they didn’t work properly. They slid off the mast inside the sleeve and they were sluggish to rotate. Then I shortened the 3 main batten to bring them forward and away from the mast by 6” so that they now intersect the seam of the mast sleeve which runs from the top to the bottom tack of the sail. I then restitched the batten’s pockets for the new shorter length.
This should allow me to give an even tighter leech, if required, while still allowing the sail to rotate. In the end, I hope to extend the light wind range of the sail..
I’ll see the results next summer because now we are in the dead of the winter here. If it doesn’t work, I’ll have nothing to lose. If it works, I’ll’ do the same with my Gaastra Pilot 6.5. If I can extend the light wind range of both these smaller sails, then may be I won’t need to use the larger sails any longer to subplane.They are somewhat uncomfortable due to their size. I am sure it is also a question of technique, because some people have no problems, but if I can use smaller sails, why not?

Francone

Francone, I think I understand what you are doing in attempting to make your sails better suited to crosswind sailing in light wind. In crosswinds when sailing at low speeds it is best to maximise lift (drive) from your sail while not being concerned about high drag. The reason for this (see picture) is that the apparent wind is across the board and so your drag is in a sideways direction and doesn't slow you down much - so no need to try and minimise drag, just maximise the lift and this will give you best power from the sail and best low-speed sailing setup for sailing in a crosswind (or downwind) direction. Your sail shapes seem like they are maximising lift at the expense of high drag, exactly what you want for sub-planing cross-wind. (If attempting to go upwind or planing in light wind, the apparent wind would come more from the front and drag will be directed more in the backwards direction, so it would then become important to minimise drag - so in those conditions a low-drag race sail would be much better.)