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Radial or Triradial Headsail

Discussion in 'Ask All Sailors' started by dlochner, Feb 12, 2018. Add this thread to a FAQ

  1. dlochner

    dlochner

    Joined Jan 11, 2014
    1,448 posts, 389 likes
    Sabre 362
    US Fair Haven, NY
    It is time to replace the genoa on Second Star. For a couple of reasons I moving to a 135% genoa from a 150%; we are getting older and a slightly smaller sail will be easier to handle and we hope to do some extended coastal cruising where we might find stronger winds. Currently we start reefing the main or rolling in the 150 around 18 knots (depends on the point of sail). With a smaller headsail I anticipate we won't have to reef until the winds are in the low to mid 20s.

    Both lofts are quoting the same fabric, Contender CDX and the prices are close enough that cost isn't an issue. What are the relative advantages and disadvantages of each design?
     


  2. Jackdaw

    Jackdaw

    Joined Nov 8, 2010
    7,999 posts, 1,580 likes
    Beneteau First 36.7 & 260
    US Minneapolis MN & Bayfield WI
    There are a few extra panels and a bit more sewing/glueing on a tri. And a bit more wasted cloth. So more manufacturing costs are slightly higher. Now while the loads are less on the tack than on the head and clew, a tri-radial sail will (all else being equal) be better performing than a bi-radial. More cloth oriented along the load paths. So do the tri unless there is a compelling reason not to.
     


  3. BarryL

    BarryL

    Joined May 21, 2004
    692 posts, 18 likes
    C&C 110
    US Mt. Sinai, NY
    Hey,

    Do you keep the bottom of your boat very clean? Do you have a folding or feathering prop? Do you trim your sails constantly? Are you sheets a very low stretch line? Do you adjust the sheet leads depending on point of sail, wind strength, and heel? If you answered no to any of those questions you will never notice the difference between bi and tri radial.

    Good luck,
    Barry
     


    Parsons likes this.
  4. dlochner

    dlochner

    Joined Jan 11, 2014
    1,448 posts, 389 likes
    Sabre 362
    US Fair Haven, NY
    Since I do all those things, what kind of difference might I notice?
     


    Will Gilmore likes this.
  5. Bosman

    Bosman

    Joined Oct 24, 2010
    292 posts, 27 likes
    Solina 27
    CA Wabamun, Alberta
    I had a similar dilemma a couple of years ago when I replaced my cross-cut sails. Price difference between the bi-radial and tri-radial was not a lot. I was "interviewed" on my sailing habits, range of wind etc by the sailmaker. In the end, I was told the tri-radial will keep it's shape longer over the useful life of the sail. At that point I made my decision with tri-radial design. NOTE: while the main is tri-radial, my 105% jib is tri-radial/bi-radial hybrid with vertical battens, again this was the sailmaker's recommendation. I do not regret a single penny spent, besides the sails look awesome.
     


  6. Parsons

    Parsons

    Joined Jul 12, 2011
    467 posts, 125 likes
    Catalina 36
    US Bay City, MI
    This is a really good list of questions. It is much more pertinent than asking "Do you race?". Many of us don't really race, or only occasionally for a weekend, but still care about performance.
     


  7. dlochner

    dlochner

    Joined Jan 11, 2014
    1,448 posts, 389 likes
    Sabre 362
    US Fair Haven, NY
    Talk to me about those vertical battens. Are they necessary because of the design? Do they work?

    Also, I wasn't entirely clear in my description, one sail maker is suggesting a "clew radial" all panels radiate from the clew.

    And yes, having awesome looking sails is most important. :)
     


    Will Gilmore likes this.
  8. Bosman

    Bosman

    Joined Oct 24, 2010
    292 posts, 27 likes
    Solina 27
    CA Wabamun, Alberta
    The vertical battens allow to increase the sail area while maintaining same foot. On a normal jib, the leech is 'hollow' in order to maintain it's tension and prevent flutter. I wanted larger sail without changing the foot and this was perfect solution for me. In your case, you might be able to go down to ~120% foot while keeping same sail area as ~135% (more or less). The sail would be easier to handle and faster to furl. This is something you should discuss with your sailmaker. Some reading materials:
    http://www.uksailmakers.com/racing-genoa-construction-options/vertical-battens/
     


    Will Gilmore likes this.
  9. Jackdaw

    Jackdaw

    Joined Nov 8, 2010
    7,999 posts, 1,580 likes
    Beneteau First 36.7 & 260
    US Minneapolis MN & Bayfield WI
    Genoas can't have positive roach, both from a rule and practical perspective. Look at how much hollow your genoa has now to see why.

    Jibs can have zero hollow, and if so will have battens to support the leech. I have seen battens put on jibs that didn't need them, just to look cool. Now THAT'S silly!
     


    Last edited: Feb 13, 2018
  10. jssailem

    jssailem

    Joined Oct 22, 2014
    4,125 posts, 1,064 likes
    CAL 35 Cruiser
    US Salem, Moored Port Everett WA
    Less money in your boat checking account.
     


    Will Gilmore likes this.
  11. Larry -- DH

    Larry -- DH

    Joined Jun 14, 2010
    249 posts, 88 likes
    Quorning Dragonfly 1200
    US home
    I just bought a clew radial Genoa from Sobstad, with vertical battens in the leech. They’re still nicely boxed in my garage and I only have seen them pictures from the loft. Regardless, I’m sold on the idea until experience tells me otherwise. There really shouldn’t be high loads along the luff radian between tack and head, and there’s a luff wire in there that should take up most of it.

    PS - yeah, they’re made of Carbon-Fiber Dimension Polyant Lightskin - dark grey. I think they’re going to look bad-ass on my tri.

    PPS - The sailmaker says the battens will reduce flutter/wear and improve sail shape.
     


  12. BarryL

    BarryL

    Joined May 21, 2004
    692 posts, 18 likes
    C&C 110
    US Mt. Sinai, NY
    Hey,
    The triradial will hold it's shape for more years than a biradial. So, if you have a triradial, AND you do all those things, after a few years you will point a little higher and sail a little faster than your friend with the same age biradial sail.
    Barry
     


    Will Gilmore likes this.
  13. dlochner

    dlochner

    Joined Jan 11, 2014
    1,448 posts, 389 likes
    Sabre 362
    US Fair Haven, NY
    We're talking to the same loft.

    My goal is to get a sail that will last awhile and maintain its performance especially since I'm moving to a smaller sail. If I was going to get a 150%, I'd probably stick with a dacron sail and would seriously consider a triradial dacron using the Fastest Challenge fabric, but we're looking for a smaller sail so a bump in performance is desired.

    The question that is unanswered is, if a clew radial is that good a design why isn't everyone going that way? Or maybe they are and I'm just an old curmudgeon who is not keeping up with the times. This is not a time that I want to be on the bleeding edge, a step or two back from the leading edge of sail technology is just fine with me.

    Still talking to the lofts. Thanks to all for the feedback.
     


  14. Larry -- DH

    Larry -- DH

    Joined Jun 14, 2010
    249 posts, 88 likes
    Quorning Dragonfly 1200
    US home
    Dave, it was Rich Wilber who invented tapedrive sails and patented it. (Other lofts pay royalties to Sobstad if they use it). He’s now saying he’s analyzed the loadpath on working genoas and it’s mostly radiating from the clew. (They did my mainsil in triradial because the loads are different, especially considering reefing.)
    I tend to think these guys know what they are doing.
     


  15. jon hansen

    jon hansen

    Joined May 25, 2012
    523 posts, 145 likes
    john alden caravelle 42
    us toledo ohio-----sturgeon bay wis sturgeon bay, wis
    dave, some thoughts to share on modern sails and size. all glued sails have a shelf life. the glue wears out way sooner than stitches do. by going to the smaller headsail you will be opening up the slot between the sails and will improve the performance of your main. giving you some of the bump your looking for back.
    having dacron sails give less jolting to your rig and gear. tape drive genoas rub on the rig with every tack. those tapes do not like that. the wear is faster. to get the bonus of racing sails you need to hand drive at all times. tweek the sheets at all times. remove all the cruising gear that creates drag from your deck. etc etc.
    these are my personal real life, using this gear, observations.

    just some food for thought. happy sailing
     


  16. Larry -- DH

    Larry -- DH

    Joined Jun 14, 2010
    249 posts, 88 likes
    Quorning Dragonfly 1200
    US home
    Some glued sails are better than others. My last laminates gave me 10 years and it wasn’t the glue - it was the Mylar breaking down at creases and folds. I could have gotten a few more years out of them, but I don’t like the patches look.
    As for shape- they held perfectly, and I doubt they sailed any different than the day they were new. You can’t say that about Dacron sails that have been through storms every year for 10 years, single and double reefed, etc.
     


  17. Bosman

    Bosman

    Joined Oct 24, 2010
    292 posts, 27 likes
    Solina 27
    CA Wabamun, Alberta
    There are cruising laminates available that feature external taffeta made out of, I'll call it "dacron family" material. These are designed specifically to answer need for high tech fabrics on masthead rigs, where as mentioned by jon hansen, large overlapping headsail is to rub against the spreaders, mast and anything else in between. Perhaps this type of sailcloth is the solution? Again, as I mentioned earlier, do talk to you sail maker.
    http://www.dimension-polyant.com/en/Laminate_Cruising_2_3_1.php
     


  18. jon hansen

    jon hansen

    Joined May 25, 2012
    523 posts, 145 likes
    john alden caravelle 42
    us toledo ohio-----sturgeon bay wis sturgeon bay, wis
    dupont quit making dacron many years ago. i like the term 'dacron family'. there is no real dacron any more as i understand it.
     


  19. Will Gilmore

    Will Gilmore

    Joined Oct 19, 2017
    1,346 posts, 439 likes
    O'Day 19
    US Littleton, NH Littleton, NH
    I haven't found a reference to monofilm sails for bigger boats, but sailboards and some small, high performance catamarans and hydrofoils are using molded sails. They hold their shape longer, wear better, but can delaminate in a few years. Some processes are more expensive, but other construction methods claim to be less expensive. Monofilm molded sails are lighter and can have multi-radial fibers molded into them. Their surface is smoother and have superior laminar flow. [​IMG]
    North Sails and Precision Sails are two major lofts making them.
    They use a female mold and high pressure heat to laminate them from extruded sheets.
    Here are a couple of links of you are interested
    https://www.google.com/amp/s/www.su...ween-x-ply-and-monofilm-windsurfing-sails/amp

    https://www.continentseven.com/ben-...ing_wp_cron=1513103793.0785739421844482421875

    Here is a link to a loft that claims the use of IRIS 3Di molded technology from off-shore racing sails is cheaper and lighter and more durable compared to "traditional" monofilm technology. Funny, but interesting.
    https://www.phantom-international.com/irissails/

    - Will (Dragonfly)
     


  20. Larry -- DH

    Larry -- DH

    Joined Jun 14, 2010
    249 posts, 88 likes
    Quorning Dragonfly 1200
    US home
    My new headsail is the DP Lite Skin in that link you referred. The Lite Skin cover layer is a laminated blend of CF and polyester, with a CF scrim in the center. The sailmaker chose the same cloth, a CF laminated scrim, but without the Lite Skin exterior for the main, saying that the skins add weight aloft and the main being full-battened is less vulnerable to flogging and chafe (except batten pockets which are covered with chafe strips). They assured me it would hold up as well as my last sail, or better. As built, the main is 98 pounds without battens, so I wouldn’t want to add to that unnecessarily. Decided to trust them and go with their recommendations. The team at Sobstad has been a pleasure to deal with, and very knowledgeable and patient. Great communication too, even though it was all by phone and email/photos.
     


    Last edited: Feb 16, 2018

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