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U2U2U2
Joined: 06 Jul 2001
Posts: 5467
Location: Shipsterns Bluff, Tasmania. Colorado
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adywind
Joined: 08 Jan 2012
Posts: 665
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 Posted: Sun Jan 11, 2015 12:41 pm Post subject: |
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| TheAdmiral wrote: | | My 6.0 matrix will not rotate without max downhaul and loose leach almost to the boom |
That's becouse you are using a soft top mast in a stiff top loving Gaastra sails! You BIC 293 guys need to start matching your sails and mast , would you please?!!  |
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ittiandro
Joined: 22 Nov 2009
Posts: 294
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| Posted: Sun Jan 11, 2015 6:53 pm Post subject: |
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In response to your comments in this post and elsewhere about my difficulties in light wind sailing and the question of DH, more particularly your suspicion that I may be using the wrong mast for the sail, here is the story.
The mast I am using is a 460 cm Gun Sails mast,( 55% carbon) with a ICMS of 25 , which puts it into the constant curve category. It should therefore be compatible with my Ezzy, according to the Seabreeze link http://www.seabreeze.com.au/forums/Windsurfing/General/compatible-mastsail-brands/
Concerning the Severne Focus, I realize now that Severne makes hard top masts for their sails. There might be a potential mismatch here, but their masts are listed as borderline with constant curve masts, as per http://www.unifiber.net/2012/mast-selector. So, although it is a less-than-ideal match, I don’t think this is the problem.
The more I read in the forums, the more I realize that perhaps my problems are due, at least in part, to improper DH. In fact, I used to set the DH by pulling or releasing the tension by as much as 5 cm ( or more) up or down, when in fact the play shouldn’t be more than 1-2 cm. Maybe I was downhauling either too much or too little !
Next season, (which seems to be rather far, since we are at 20 C. below with a foot of snow….) I’ll tweak my rigging in the light of what I have learnt from these exchanges and see how it goes..
Concerning the issue of tight leech, I am old enough to have known the old sails with a pointed tip. There was even a string ( yes, a string!) along the leech length which you could tighten or loosen for more or less leech tension. The leech was probably much tighter than anybody would advocate for a shortboard sail today. There certainly is a reason for this in gusts or strong winds, but when it comes to light winds, I believe modern windsurfing technocrats may be demonizing a tight leech too much.
In fact, when subplaning in 10-12 knts winds with my longoard, a long time ago, I never experienced with the old sails (and their tight leech, no-floppy top) any of the problems that modern windsurfers fear: top-heavy sail, being catapulted forward, etc. For one thing, I was always able to sail with smaller sails (and faster!) than I can today , although planing was out of question, (also because those first generation longboards weighed like hell!).
Fortunately, there seems to be a revival of longboarding today, with boards and sails which optimize sub-planing while allowing planing. Perhaps this is the way I’ll go.
Thank you for your responsiveness
Ittiandro |
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U2U2U2
Joined: 06 Jul 2001
Posts: 5467
Location: Shipsterns Bluff, Tasmania. Colorado
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| Posted: Sun Jan 11, 2015 10:07 pm Post subject: |
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http://www.peterman.dk/masts-all-imcs01.htm
OR
http://www.unifiber.net/2013/mast-selector
as you posted.
The Gun Sails mast will fall into a constant curve or ACTUALLY a constant curve flex top group. 10--12 is CC 13--15 is CC flex top. Your 55% carbon is 13.3
Ezzy masts are 90% and are RDM, Ezzy sails will work with any mast RDM or SDM, sorry you never stated which yours is,, if its non compatible you will lose range and either top end or low end. Since the sail DOES have huge range, you may only lose a little something using a mast thats NOT IDEAL. I have never used a Gun mast on my Ezzys.
The mast feel itself is dictated by
OVERall stiffness
The ratios between the mid, 1/4 and 3/4 bend points referred to IMCS BEND Characteristics.
The carbon content.
The carbon orientation. More zero axis fibers=better response.
The 55% carbon is low, the mast may be ok, but I think you are losing some potential of the sail with it.
Reducing the batten length is ..sugar coated version. Not realistic
TOO much downhaul on Ezzys will make them gutless, and wont handle being well powered up either. Check out the rigging guides provided and OR post a photo of the GunMast Ezzy please
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ittiandro
Joined: 22 Nov 2009
Posts: 294
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| Posted: Sun Jan 11, 2015 10:32 pm Post subject: |
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| U2U2U2 wrote: |
Ezzy masts are 90% and are RDM, Ezzy sails will work with any mast RDM or SDM, sorry you never stated which yours is,,
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Thanks
I don't have an Ezzy mast, though. Only an Ezzy Freeride 7.5 sail on a Gun Sails 460 cm mast SDM. I described all this in full in my post. What you say confirms that I am not terribly off in matching the sail with the mast. It could be better, but I think my problem is less with the equipment than with improper rigging/DH. Probably I am hitting a wall also due to certain inherent downsides of shortboarding when it comes to light winds. |
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adywind
Joined: 08 Jan 2012
Posts: 665
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| Posted: Mon Jan 12, 2015 12:17 am Post subject: |
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On paper everything looks good ...but the reality is very different it seems 
Here's what I've found: a real world test
http://pulinat.purjelautaliitto.fi/surfbb/viewtopic.php?f=2&t=3923
Check out what they are saying about the price point Gun Advantage 460 -which is probably your mast . It appears to be a soft top after all!
Problem solved! You are welcome !Start saving for a proper mast idealy Ezzy-you'll love the RDM. Quality 2nd hand will still be bether then a cheap new ! |
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adywind
Joined: 08 Jan 2012
Posts: 665
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| Posted: Mon Jan 12, 2015 5:12 am Post subject: |
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PS: look what also came up:
http://www.star-board.com/forum/showthread.php?p=57542
Your Q&A with Rodger from 2012 just before you were about to buy that mast. Btw you say then that it's 35% and here that it's 55%. Which one is it?! Actualy it doesn't matter-that mast is a cheap peace of trash with random specs and I can't believe you suffered for so long !!!
To summarise: you have a heavy board, gutless sails becouse of wrong mast, gusty lake conditions and perhaps far from perfect technik. I don't want to appear rude, but you need to cover many bases to achieve any improvement mister  |
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jingebritsen
Joined: 21 Aug 2002
Posts: 3371
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U2U2U2
Joined: 06 Jul 2001
Posts: 5467
Location: Shipsterns Bluff, Tasmania. Colorado
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| Posted: Mon Jan 12, 2015 10:46 am Post subject: |
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| ittiandro wrote: | | U2U2U2 wrote: |
Ezzy masts are 90% and are RDM, Ezzy sails will work with any mast RDM or SDM, sorry you never stated which yours is,,
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Thanks
I don't have an Ezzy mast, though. Only an Ezzy Freeride 7.5 sail on a Gun Sails 460 cm mast SDM. I described all this in full in my post. What you say confirms that I am not terribly off in matching the sail with the mast. It could be better, but I think my problem is less with the equipment than with improper rigging/DH. Probably I am hitting a wall also due to certain inherent downsides of shortboarding when it comes to light winds. |
Excuse me. I read and understood that you had a 460cm Gun Mast of 55% carbon, nowhere does it state its a SDM. The SDM will be slightly more tolerant of a bend curve thats not ideal.
You are probably correct in that you are not terribly off, perhaps off enough to detract from the performance of a great Ezzy sail.
What are inherent sides of shortboarding ?
Define a shortboard ?
Heres what I think, remove the battens in question,
a. sail once with no battens, just to see how it performs
b. replace said battens with bamboo , huge flex
c. use duck tape to reinstall
d. photo journal the entire process
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Wind-NC.com
Joined: 30 May 2007
Posts: 980
Location: Formerly Cape Hatteras, now Burlington, VT!
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| Posted: Mon Jan 12, 2015 11:14 am Post subject: |
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Hi, one way to achieve your goal, if I read it correctly, is to use a stiff top mast like a Maui Sails/Severne/Gaastra/Naish. Maui Sails is the stiffest top and should do the best job at increasing leach tension up top while still allowing the bottom of the mast to flex enough so that the lower battens have a reasonable curve up front.
The overall effect of this setup will be a flatter draft overall, but it will be centered higher and further back, and will "utilize" more of the upper sail cloth area for power in sub planing conditions.
Hope that helps and makes sense!
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