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Lorne Chapman
Posts:149
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| 09/02/2008 5:27 PM |
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Proposed Rule:
3.6.2 All sails shall be constructed of a single layer of fabric except for permitted reinforcements, constructional seams, tablings, reefing and anti-chafe patches, camber lines, numbers, and repairs to damage. The mainsail and jib shall be made of woven polyester. The genoa shall be made of either woven ply and/or laminate ply of one of the following materials: polyester, aramids, HMPE. The spinnaker shall be made of nylon. When woven polyester or nylon is torn it shall be possible to separate the fibers without
leaving evidence of a film. No sail shall have elastic (shock) cord in the luff or foot.
Justification of Proposed Change:
1. The current sail cloth restrictions represent technology that is 15+ years old. By allowing newer technology you would encourage development in the class. This development would force sailmakers to again dedicate time and resources to the class which has seen a drastic decline in there level of effort over the past several seasons. Additionally, it would demonstrate to both members, and more importantly, future members, that the class is not stagnant and is in fact progressive in its thinking.
2. Pentex has extremely limited applications at this time outside of sailcloth. As such, there is only one supplier worldwide of the material thus limiting competition and unnecessarily increasing costs. Additionally, sailmakers are finding a very wide range of quality from lot to lot with no recourse.
3. Pentex by its nature is a relatively slippery and stretchy fiber which creates issues with adhesives in laminates and has a high initial stretch, the net result being that the fibers in a Pentex sail move and shift more thus contributing to a shorter useful life and infact contributes to shrinkage and thus reduced lifespan.
4. The J24 genoa covers a range of wind strengths from 0-20 knots. At the upper end of this range the Pentex fiber begins to reach its limit of shape holding ability thereby transferring load to the film substrate/adhesive and creating permanent deformation, increased shrinkage and delamination resulting in loss of designed shape. Unlike other factors which contribute to the aging of a sail, this type of loading does far more damage than the combined effects of all others such as UV, film shrinkage. By changing to an aramid fiber, which is approximately two to three times stronger, the film substrate will not experience loading.
5. By maintaining a bag weight close to the current limit of 6.5 Kg we would be creating sails which are twice as strong while limiting the creation of an inbalance in competition between those with aramid sails vs PEN sails due to weight.
6. While no fiber will ever completely mitigate the effects of film shrinkage, using a more stable fiber, stronger fiber, more consistent fiber, will result in a more durable sail thus giving the class members more value for their sail purchase dollars.
Net Effect of the Proposed Change:
1. Sails would hold their design shape over a wider range of wind strengths. This would allow sails to last longer and benefit the large majority of owners who expect to get more than one heavy air regatta of use from their investment. The majority of class members are those who use their boats for local regattas and club racing and the benefit would be that the sails that trickle down to this level of sailing will retain a higher percentage of their original design shape. Those competing at the highest levels of the class will still be purchasing new sails for major events so the effect here is small.
2. The cost of a genoa would increase 15%-18% over the current costs. This is a minor increase in costs given the added durability and life span of the sails. |
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Nils Jannichsen
Posts:65
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| 09/02/2008 7:30 PM |
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Sounds good,
Does this also open the possibillity for 3dl genoas?
if not why and what part does limit this?
thanks Nils |
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Lorne Chapman
Posts:149
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| 09/05/2008 3:39 PM |
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| Yes - 3DL sails are covered by the proposal |
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Tim Winger
Posts:49
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| 09/05/2008 3:47 PM |
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I like it!
So what materials are still off the table for genoas? What will we be looking for on the enforcement side? Carbon fiber - what else? |
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Paul Beaudin
Posts:7
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| 09/06/2008 12:27 PM |
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Only moving to allow already outdated materials like aramids (kevlar/tawron) and hmpe ( spectra/dyneema) is short sited, HMPE is not used and Aramid fiber, on its own is, has been on the way out, as we know, due to poor longevity. Current sails using carbon fibers, in various fashions, have become the standard in sailboat racing, because they outlast all of the above by a factor of 4 and provide the best long term value. J-24 genoas using Carbon can be produced for 10- 20% more than the current sails and with certain fabrics, in the same price range. These sails will last 4, or more, times longer than the current sails at 3/4 of the weight. It is a no-brainer.
The bag weight must also be reduced or eliminated to effectively make this change. It has done nothing for sail longevity. A high tech sail at an overly heavy weight only increases the cost and hurts performance. The demands of the customer already encourage sailmakers to deliver a long lasting affordable product. A free market will deliver the best sails for the best price. |
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Paul Scalisi
Posts:9
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| 09/09/2008 11:31 AM |
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I respectfully beg to differ regarding Paul Beauding post. Kevlar is the most popular fiber in sailmaking currently and is not going anywhere any time soon and given the size of these boats and loads, carbon does not offer a significant advantage. Kevlar, while available for many years has seen development and refinement throughout that time, the kevlar of today is vastly superior to that of 15 years ago, not only in flex but in UV resistance, the two primary concerns with Kevlar. If you asked any sailmaker or cloth supplier to build you a no holds barred sail, they will all recommend kevlar. Carbon is also much more expensive than kevlar at this point. As for the bag limit, I think we need to maintain it close to where it is so as not to obsolete every sail currently out there as well as force the new sails to be slightly overbuilt, therefore last longer. As experience with the new sails grows we can revisit bag weight in the future. Switching materials and eliminating the bag limit will just allow sailmakers to reduce denier/fiber in the sail and thus shorten lifespan back to where we are. The trade off here is a heavier weight sail which given the fact we sail one design is a non issue.
Lets keep the discussion going as we have until Oct 3 to really find out what you desire as class members. Feedback is king!
Paul |
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Paul Beaudin
Posts:7
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| 09/09/2008 2:23 PM |
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Paul, I really don't like to disagree with our national class president, but I beg to differ. As a sailmaker, for a major brand, specializing not in J-24 sails but mainly larger racing boats, virtually, all of our racing sails, that are not restricted by class rules, use Carbon as the primary load bearing fiber. True, laminated sailcloths, including aramids, have gotten better over the years and include better UV resistance in the films, but aramid fibers are still the same, losing much of their strength after a short amount of use. It could be, carbon is overkill, but I don't think we should restrict it. Carbon in uneffected by UV and (in it's basic recreational grade) has much better flex life than aramid. A carbon sail can last, at least, twice as long, for a 15% premium. When you figure races per sail, it's a bargain. I believe, restricting the fiber to aramid only benefits the sailmakers, myself included. But it is a heck of a lot better than what we have now.
As for the bag weight. The current poly/pen cloths perform so poorly, we use beefier materials just to get a sail to last through the first regatta. Still, the patches, on every brand sail, have to, and are, overbuilt to hit the bag weight. Just find a pre-bagweight sail and compare it to a current sail. Changing to high tech fibers the cloth will be lighter and stronger. Reducing the bag weight will make a better, more economical sail. The current rule limiting laminated cloths to no less than 138 grams per square meter and allowing only single genoa on board, make an overly light sail impractical.
Respectfully, PB |
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Pete Ramsdale
Posts:14
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| 09/09/2008 9:37 PM |
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Fully support the move to get away from using Pentex - don't mind brown or black sails, but would like them to last more than a few regattas. Genoa damage comes from stretch at high loads, UV, and crew abuse, but I suggest that much more comes from dragging the recalictrant beast round the rigging and mast.
So how to upgrade to longer lasting cloth, and keep costs under control? How about scrap the genoa completely, and move to a 3 sail plan - using improved cloth for the jib, which will allow a more powerful shape in lighter breeze, yet be able to be flattened for the upper end. Overall costs come down.
Just a thought!
Pete |
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Tim Winger
Posts:49
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| 09/10/2008 2:24 PM |
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My current research supports a lot of what Pete Ramdale says just before my post. The biggest reason our genoas wear out is not the stretch of the cloth, but the abuse they take in tacking. The leach goes very quickly depending on the batch of Pentex/Mylar material. The Pentex is so slippery that the bond to the Mylar is hard to control and varies batch to batch for all the cloth suppliers. The beating the overlapping genoas take on the rigging hastens the breakdown of that tenuous bond.
Most modern one designs have gone to a jib. Some years back, North Sails and Brad Read suggested an enhaced jib for the Class. Whether we want to look at that again is a separate, but not unrelated issue. I'm starting to like it more and more.
Aramids have advanced and gotten better on their shortcomings of uv problems and inflexibility. They are not out of date for sails of the size and power required for the J/24. I believe Paul, the sailmaker of previous posts, admits that he makes sails for larger boats where carbon fiber certainly does become cost effective. One of the biggest improvements that aramids would bring to J/24 genoas specifically would be that they will bond better to the mylar so that the composite material will stand up better the the abuse it will get from tacking in tight fleet racing in winds up to 20 knots. A side benefit will be that the shape will hold up better as well in 20 knots of wind.
The 6.5 kilo bag weight should also remain. The beefier cloth and patches are not required as much for holding shape as for keeping it from breaking down from the abuse of tacking around the rig. This bag weight would limit the benefits of membrane technology like 3DL. The effectiveness of the flexible fiber placement for handling loads makes a much lighter sail possible with membrane technology, but the abuse the sail takes would probably negate all of the strength to weight performance gains with shorter sail life, which is not our goal.
The J/24 Class is certainly not on the cutting edge of technology and speed anymore, but we continue to attract sailors to the Class because it is the best competition for the buck spent you will find in any class. Let's not lose sight of our strength.
Tim Winger |
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Nick von der Wense
Posts:4
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| 11/03/2008 4:03 PM |
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I strongly suggest the class investigate the move to lightening the max weight to 360 kilos and a Class Jib made off carbon or kevlar.
This would profoundly increase the performance and durability of the sails, lower the cost even more for traveling and club programs alike, and reinvigorate the class.
You can not "appear" to be progressing the class, you have to actually do it.
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Nick von der Wense
Posts:4
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| 11/03/2008 4:06 PM |
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I want to be clear that the genoa needs to be eliminated and augmented by a 105% jib with modern materials.
I would propose a one year transition where teams could use either configuration, but not change during an event.
Finally the class adopts the use of the new sails for the 2011 worlds.
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Nick von der Wense
Posts:4
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| 11/09/2008 8:09 AM |
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I have taken the time to read the past 8 years minutes from each of the world councils meetings. It appears that there was some serious consideration given after the 2003 Pan AM games, where all the crews sailed with 4. The response was very positive. The boats suffer from too much weight on board in optional equipment and crew weight. The genoa quickly wears out and makes the boat hard to sail.
The Gold Standard of the Class, as identified in the recent strategy section of the currently posted 2008 minutes is the highly evolved and refined class structure, the volunteering members and the world council. However I would argue that the Gold Standard of the CLass is NOT the GENOA, or the WEIGHT LIMIT. The Gold standard is definetly the boat itself, the sailors, the low cost of entry, the numbers of boats, the tradition, and of course, the class' willingness to highly manage itself.
A modernization project modeled on the Farr 40, which changed to mast head kites 2 years ago, or the E-Scow, which changed to the bowsprit would be a fantastic class initiated path to encouraging participation by lowering cost and improving performance.
Personally I would suggest that class further investigate and implement modernization, especially the PAN AM configuration.
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Ron Medlin
Posts:4
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| 11/14/2008 5:34 PM |
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I am starting to lean towards Nick and Tim's points of view. In my opinion, this change will increase, not decrease the cost of racing J24's. In the 10 years I have been racing sailboats, every single change I am see proposed at any level of the sport has had the same effect, it has raised the cost of competing. The key data in the above proposal is that we are looking at a 15%-18% increase in the cost of an already expensive genoa. I bet when the sail comes out, it will be a lot more expensive than that. I know the claim is that the sails will last longer. But, for practical purposes, that won't matter. The top boats will still show up with brand new sails every regatta and if you want to compete with them, you'll have to do the same thing. It won't matter what the sails are made out of, dacron, pentex, kevlar or carbon if you want to compete with the top boats, you'll need a new genoa every regatta. The problem is that now, it will cost "15%-18%" more to buy that sail.
The only way to actually cut costs is to lower, not increase, the cost of the sails by going to the Jib set up or by limiting the # of genoas a Class helmsman can purchase per year. |
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Lorne Chapman
Posts:149
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| 11/14/2008 9:02 PM |
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| First - the proposal that is on the table is to add aramid and HMPE fibre laminates to the list of permissible materials for genoas - which currently includes woven polyester and polyester laminates (Pentax). Nothing is being replaced or eliminated - owners would simply have a wider choice. There are a few other aspects to this discussion that have not surfaced. Opinions are mixed amongst the experts that we have consulted as to the extent that aramid fibre genoas will outlast Pentax. Some tell us the useful life of aramid laminate genoas will be 30% - 40% longer - others say that there won't be a noticeable increase. Opinions are also mixed as to whether it is just the flogging on the rig that affects the useful life of the genoas, or whether it is also sailing the genoas in the upper wind range. On the prices of the aramid fibre sails - the estimates we are getting from sailmakers we have surveyed are in the 10% - 15% over the cost of a Pentax genoa. On the issue of the bag weight (currently 6.5 kg), some sailmakers believe that a heavier and therefore stiffer "cloth" will actually not last as long under the flogging on the rig as a slightly lighter cloth that is more flexible. The difficult part is that the flogging occurs on in the leach area - where the loads are greater and better handled by a heavier "cloth" - so a design problem for the sailmakers. Hampering the design of sails with the proposed additional laminates with an artificially high bag weight just doesn't make any sense. Why would we want to penalize "string" sails if these turn out to be the best solution for the class. We want to get the best sails possible. The current thinking is that a modest drop in bag weight to around 5.5 kg will provide the latitude needed to optimize the designs. We don't have much experience in the class with sails made from aramid and HMPE laminates - there are a few currently being tested but we are unlikely to get much on the longevity issue for a while. There is pressure from some segments of the class to push on with the rule change quickly - let the early adopters buy the new sails and see where the results settle. This is a feasible approach as the difference in expected boat speed between using an aramid laminate genoa and one made of Pentax will be negligible if anything and experience can be gained on the longevity question. There is also the aspect of using aramid fibre laminates being perceived in the sailing community as "more modern" and thus be a factor in attracting people to the boat. The other approach to implementation would be to hold off for 6 to 12 months to let some tests be done. The class does not have good mechanisms for running tests - and the results will still be a lot of opinions - some informed and others from those who have an opinion but are not sufficiently informed. Sailmakers will likely do only limited testing if they believe the class is still sitting on the fence as to whether to proceed. The aspect of limiting sail purchases annually also comes into this. We have seen sails evolve to designs that are peculiar to certain sailing conditions. The reason the class has not limited sail purchases in the past is that with boats travelling to high level events - nationals, continental and world championships, those boats with sails cut for home conditions that are very different from where the event is being held would be at a disadvantage. Perhaps with the cost of sails having increased it is time to rethink this one. On the additional question that has crept into this discussion - going to the jib only headsails yes they work in some conditions. However in other conditions the boat will perform like a 400 lb. pig in the Kentucky derby. This would change the whole character of what a J/24 is. I'd suggest this be a separate forum topic as the new materials for the genoa topic has enough of its own complexity as per the discussion above and from the previous participants. |
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Tim Winger
Posts:49
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| 11/15/2008 9:36 AM |
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From the time of my post above until now, there has been much discussion within the Class and with sailmakers and others. I have come to pretty much the same place as has Lorne Chapman. Lorne's view stated above is the consensus view of those who have been active in researching and crafting this rule change.
I differ from Lorne just a bit in that I don't believe the 105% concept with a lighter boat would be terribly slow in any conditions. It would be slower in some conditions certainly. One thing for sure is that it would change the character of the boat, and that is something that we have reviewed and rejected at this point as doing more harm than good. The genoa is more difficult to use and as such becomes one of the challenges of sailing J/24s. Many folks in the Class still like that challenge.
Tim Winger |
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Nick von der Wense
Posts:4
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| 11/15/2008 9:32 PM |
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With a great amount of respect to Lorne and Tim, I would have to say that a 15-20% percent cost increase is really an unacceptable increase without a measurable gain. We may increase durability, but performance will not improve 5%. That being said i applaud the endeavor entirely to examine the issues facing the owners and the class, particularly how to increase the performance without dramatic cost increases.
I would not be surprised if we see the new Genoa's at the Midwinters, look forward to it.
A few other comments. Having sail tested and witnessed the sail programs at North and Quantum evolve over the last 15 years rarely (actually i have never heard of one) is there a localized design for home waters. Almost always the designs are the same. For events in SF, the sail makers change a bit to compensate, such as a deeper main to compensate for overbend with alot of backstay on.
As far as the 300 lb pig in Kentucky comment and the boat being too slow with just a jib, I urge everyone to open up there thinking after understanding this simple fact. Tim Healy was second in the Fleet 50 Thursday Night Spring Series in Newport the summer prior to the 2003 Pan AM Games, arguably the most competitive fleet, in the Pan Am configuration. EVERY OTHER BOAT USED GENOAS AND SAILED WITH FIVE. Even in the light air, Gordi, Nick, Dave and Tim would often arrive to the weather mark first, minus my fat 190 lb ass and the genoa. I would have to say this is a great TEST of this configuration.
Results for the 2003 spring series are here. Only Jens Hookenson was better, winner of the 2004 worlds.
http://www.j24fleet50.org/results/2003-spring-final.pdf
As far as i am concerned this clearly demonstrates the ability of the Pan Am configuration to exceed or be equal to the current. It also proves that you can use both for a transition! A slightly lighter boat in crew and optional equipment, a main (with full batten) and a 105 kevlar battened jib would greatly improve the performance, improve durability and decrease cost for the fifth member and the genoa.
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