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Post by sfh on Feb 27, 2021 5:37:40 GMT
Good morning
Our Jeanneau 53 has a single "inverted Y" backstay.
As I am changing the standing rigging I was considering replacing the inverted Y setup with two straight stays instead.
Is that a bad idea?
What is the design reason for the single inverted setup vs a more simple setup with two independent wires?
Thanks in advance Steen
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Post by johannes on Feb 27, 2021 6:08:56 GMT
With an inverted Y, the backstay will interfere less with a battened mainsail.
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Post by sfh on Feb 27, 2021 6:11:10 GMT
Good point. We have furling in-mast though I will check that
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Post by NZL50505 on Feb 27, 2021 10:30:21 GMT
2 separate backstays gives you more redundancy. Unless you have an especially sporty square-top style racing mainsail (unlikely on the average Jeanneau cruiser) then 2 independent backstays seems best option.
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Post by element on Feb 27, 2021 16:30:40 GMT
I don’t think I have ever heard of a failed backstay but normally two would be better than one. One my 39iP however I can only have a single stay because the backstay is adjustable, which is a very important tool for flattening the sails when the wind gets stronger.
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Post by zaphod on Feb 27, 2021 17:22:36 GMT
I don’t think I have ever heard of a failed backstay but normally two would be better than one. One my 39iP however I can only have a single stay because the backstay is adjustable, which is a very important tool for flattening the sails when the wind gets stronger. My 39i does not have a split backstay, it has twin backstays instead. At some point I would like to convert to a split backstay like yours so that I can have a backstay adjuster. The OP's boat has in mast furling so mast bend would be of no value, so the only benefit would be forestay tensioning. Backstay adjustment is the only real benefit I can see for split backstay vs twin backstay.
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Post by loredo on Mar 1, 2021 15:43:35 GMT
"The OP's boat has in mast furling so mast bend would be of no value, so the only benefit would be forestay tensioning."
This is not entirely true. A furling mast can (be) bend exactly like with a full batten main. Only trick is, releas the backstay(s), unfurl, now set the backstay tension to what you need. To furl the main, release the backstay(s), furl... The furling main responds to the backstay tension almost like a traditional main sail. I wouldn't want to be without mast bend on my furling mast. Also a cunningham works on a furling main (almost) like it does on a full battend one.
Food for thought?
Loredo
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Post by zaphod on Mar 1, 2021 18:36:22 GMT
"The OP's boat has in mast furling so mast bend would be of no value, so the only benefit would be forestay tensioning."
This is not entirely true. A furling mast can (be) bend exactly like with a full batten main. Only trick is, releas the backstay(s), unfurl, now set the backstay tension to what you need. To furl the main, release the backstay(s), furl... The furling main responds to the backstay tension almost like a traditional main sail. I wouldn't want to be without mast bend on my furling mast. Also a cunningham works on a furling main (almost) like it does on a full battend one.
Food for thought?
Loredo
I am having trouble visualizing how mast bend could flatten a roller furling main. The luff of the main is attached to the furling unit inside the mast rather than to the mast itself, so what is going to force the furler to conform to the mast bend when it is essentially free floating inside the mast? Am I missing something?
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Post by jdl01 on Mar 1, 2021 19:04:01 GMT
Our 379 has a wire rope block at the masthead, through which a single wire-double backstay runs. This allows for a single backstay tensioner which will equally distribute load between the two backstays. With regard to the previous impending argument, irrespective of flattening the mainsail, being able to shift the centre of effort aft by tensioning a backstay will affect the amount of weather helm and hence boat performance.
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Post by zaphod on Mar 2, 2021 5:52:39 GMT
Our 379 has a wire rope block at the masthead, through which a single wire-double backstay runs. This allows for a single backstay tensioner which will equally distribute load between the two backstays. With regard to the previous impending argument, irrespective of flattening the mainsail, being able to shift the centre of effort aft by tensioning a backstay will affect the amount of weather helm and hence boat performance. I don't think the center of effort is going to change significantly with backstay tension. Increased backstay tension will only move the masthead a few inches at most. Any reduced weather helm can be attributed to a flatter mainsail on a classic main.
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Post by loredo on Mar 2, 2021 8:09:55 GMT
"I am having trouble visualizing how mast bend could flatten a roller furling main."
Depends upon the mast.
The furling unit inside the mast as used by Jeanneau (Sparcraft?) is free "floating" inside the mast.
In addition the furler is rather flexible.
Thus, when there is pressure on the main from the wind the furler is pulled in contact with the mast.
Now you bend the mast, done deal.
On the opposite a mast like the Hallberg Rassy's use (I think Selden) instead has a tensioned wire inside the furler (very similar to a headsail furler) and for this reason mast bend does not change their sail shape (much).
In fact with a Jeanneau it can happen quiet frequently to hear the main furler bang inside the mast
when the boat rocks in the waves like say at anchor. Since the furler is free to move inside the mast... (I H A T E it!)
Buddies with HR's report that's not the case on their boats. I can flatten my main, the HR's can't. Mine bangs at ancor, theirs don't.
I guess, as always, everything is a compromise and nothing is perfect.
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Post by zaphod on Mar 2, 2021 16:07:00 GMT
"I am having trouble visualizing how mast bend could flatten a roller furling main."
Depends upon the mast.
The furling unit inside the mast as used by Jeanneau (Sparcraft?) is free "floating" inside the mast.
In addition the furler is rather flexible.
Thus, when there is pressure on the main from the wind the furler is pulled in contact with the mast.
Now you bend the mast, done deal.
On the opposite a mast like the Hallberg Rassy's use (I think Selden) instead has a tensioned wire inside the furler (very similar to a headsail furler) and for this reason mast bend does not change their sail shape (much).
In fact with a Jeanneau it can happen quiet frequently to hear the main furler bang inside the mast
when the boat rocks in the waves like say at anchor. Since the furler is free to move inside the mast... (I H A T E it!)
Buddies with HR's report that's not the case on their boats. I can flatten my main, the HR's can't. Mine bangs at ancor, theirs don't.
I guess, as always, everything is a compromise and nothing is perfect.
Jeanneau has been using Selden masts for more than 10 years, at least for their classic mains. All of the newer jeanneaus and Beneteaus with IMF I have seen have Selden. They use a tensioned luff extrusion not unlike those used on furling headsails.
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Post by Charlie-Bravo on Mar 2, 2021 16:50:56 GMT
I have the sparcraft furler mast, and split Y with no adjuster, ...... coming from a fully battened main sail with back stay adjuster earlier in life , initially was concerned at the lack of fine tuning, but hoping to enjoy the easy life of a furling main, I'm getting used to it, less performance but I sail fast enough for cruise and don't race ........ unless I see another SO in sight, then I just can't stop myself ! and if I can't keep up, .... I can blame the sail.
If I have to re rig again I would contemplate two aft stays just for that extra chance that I might save the mast if one breaks, at the moment I would have to use a spare halyard or topping lift as an emergency stay, hoping not to have to do it at all.
The furling only bangs when I remove the sail, I then slide two lengths of 28mm foam pipe insulation up the foil to shut it up, now it just thuds a little. CB
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Post by loredo on Mar 2, 2021 22:45:00 GMT
CB,
let me guess, you have a dacron main?
Mine is a dynema laminate which makes for far less volume inside the mast when furled.
I guess that's the reason why mine bangs. Oh my...
Zaphod,
I'm by no means an expert when it comes to what masts Jeanneau has used or is using on their boats. Mine is a 2006 SO 49 and has a Sparcraft mast. All the boats of my friends do also have Sparcraft
furling masts. Personally, I have never seen a Jeanneau with a Selden but it's not that I watch every
boat that closely either. Now that I think about it, I think I've never seen a Jeanneau without a furling main... What I know is that Sparcraft's furling masts do not use a tensioned luff extrusion.
Loredo
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Post by zaphod on Mar 3, 2021 1:11:40 GMT
CB,
let me guess, you have a dacron main?
Mine is a dynema laminate which makes for far less volume inside the mast when furled.
I guess that's the reason why mine bangs. Oh my...
Zaphod,
I'm by no means an expert when it comes to what masts Jeanneau has used or is using on their boats. Mine is a 2006 SO 49 and has a Sparcraft mast. All the boats of my friends do also have Sparcraft
furling masts. Personally, I have never seen a Jeanneau with a Selden but it's not that I watch every
boat that closely either. Now that I think about it, I think I've never seen a Jeanneau without a furling main... What I know is that Sparcraft's furling masts do not use a tensioned luff extrusion.
Loredo
Interesting. I wonder when Jeanneau transitioned to Selden, or if they source masts from multiple manufacturers. All of the 39i we looked at had Selden, and the newer boats I have looked at also had Selden. My observation around here is that most Jeanneaus in the 40ft range have classic mains whereas most Beneteaus have IMF. My thinking is that Jeanneaus tend to be a bit more performance oriented than Beneteaus so more jeanneau owners opt for classic. Certainly I see more IMF on bigger Jeanneaus for ease of handling.
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Post by Charlie-Bravo on Mar 3, 2021 8:08:17 GMT
Your guess is correct, and I treated the boat to a new sail over Christmas made from Challenge Fastnet Dacron which has yet to be tried, not as fancy as a dyneema...... but hoping for a vast improvement on the 15 year old original which became a handful in 20 knots plus, and attempting to not completely bankrupt myself in the process.
The best bit of the Sparcraft furling system is that all the furling mech can be accessed at deck level, so no stuck bearings at the top of the mast, ..... but now we are drifting from the point of the thread. CB
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Post by loredo on Mar 3, 2021 9:11:02 GMT
Zaphod,
for me it's the first time ever to know that there are Jeanneau's with a Selden mast.
Not that it means much! I was convinced that all J's had a Sparcraft rig! It is likely that Jeanneau uses multiple suppliers,
the one who offers the best product for that particular yacht model wins? Best price? Whatever... I find it interesting to see how things change in different parts of the world.
In my neck of the woods virtually ALL J's do have a furling main. Lazy? ... Me for sure!
CB, congrats on the new sail! New sails are always a vast performance improvement over the
old potato bags. Once you get used to the new sail and come to know it's performance. try to play a bit with some "fixed" pre-bend in the mast. I mean to say, increase the backstay tension so to induce a pre-bend in the mast and see how it does. Not too much though, otherwise furling becomes difficult. I started this way and found it worked just nicely.
Loredo
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Post by MalcolmP on Mar 3, 2021 9:44:10 GMT
Drifting from the original thread, but just to answer the Seldén mast story. Our 2008 39i was probably one of the first Jeanneau's with a Seldén rig.
Seldén made an inspired move to create their French factory close to all the Vendée yachtbuilders in April 2007 when they opened their facility in Le Poiré sur Vie.
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Post by NZL50505 on Mar 3, 2021 9:52:48 GMT
I had Selden on my 2006 42DS.
My current 2012 50DS is Sparcraft.
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