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18 SX rule change?
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Author:  ncmbm [ Wed Oct 14, 2009 12:03 pm ]
Post subject:  18 SX rule change?

Skipshot made mention of this in the thread on the "New In Box SX". It appears that there are many SX owners out there, and many running Whirlwind sails. The SX is most always raced as an open class boat even though it is only marginally faster than a standard 18, if it really is any faster no one knows. I really don't think it fair to race a SX with a squaretop against a standard 18. SX should be raced with wings but few race it that way. To me the only real answer is to have the F18 class grandfather the SX as an F18 compliant design. The SX in my opinion can not compete with the F18s straight up due to the foils. If there was a way to retro fit Tiger boards in the H18 wells that could eliminate the F18s advantage. Under the water both boats are similar. The top deck lip on the H18 can be problematic as opposed to the smooth transition on the Tiger but this only comes into play in higher wind speeds and heavier crews. I have addressed the F18 community about this already and really didn't get to far as they do not want to grandfather the H18 in, the SX only may be a different story.

Then for me it comes down to the fact that my boat was born a SE and has been converted to a wingless SX, I think I will forever be stuck in open class! At least this will be lively conversation.

Author:  MBounds [ Wed Oct 14, 2009 1:49 pm ]
Post subject:  Re: 18 SX rule change?

So what exactly are you proposing?

Why would you want to be F18 compliant? An 18 SX has a DPN of 71.4 (actually slower than an 18 at 71.3) vs an F18's DPN of 62.1. You'd never be able to sail to your rating.

Are you proposing a different sail plan for the 18SX?

Raced without wings?

You just kind of ramble on without being specific.

Author:  ncmbm [ Wed Oct 14, 2009 2:17 pm ]
Post subject:  Re: 18 SX rule change?

I have a tendancy to ramble when at work posting and distracted often. The question raised was about racing the SX in a class and not as an open class boat. There are never enough SX's at a regatta to form a class. So, the question becomes what class most closely relates to the SX if the boat runs a square top and/or spinnaker. F18 is the most similar class. I sail on a 66.8 number currently and you are correct, I can't sail the boat to that number. Perhaps a new class, H18 Formula, is the way to go. Set a box rule that the H18 and the SX can conform to. That way you can get more boats on the same start.

I would like to see others develop the H18 platform and it would be a point of excitement for the existing H18 owners and an encouragement for those entering the class on used boats, ie no more dead class discussion. This class could also serve as a learning curve for future F18 sailors, a stepping stone if you would in performance without the cost.

The H18 is still the best beach cat available, why not advance the platform? If the F18 designs could do what my 18 does I would have one and not be talking about this. IMO the H18 is the only discontinued platform that can be modified to modern design sails and sail controls without sacrificing performance or durability. Its darn close to running with the Tigers!

Author:  srm [ Wed Oct 14, 2009 3:48 pm ]
Post subject:  Re: 18 SX rule change?

Quote:
The question raised was about racing the SX in a class and not as an open class boat...Perhaps a new class, H18 Formula, is the way to go. Set a box rule that the H18 and the SX can conform to. That way you can get more boats on the same start.


Sounds like you weren't racing the 18 back in the late '80s, early '90s when new 18 platforms seemed to pop up every few years. First it was Magnum wings, then SX's, Formulas and spinnakers - not to mention the Hobie 21, 17 Sport, & Hobie 20, all of which, for better or worse, had a hand in weakening the 18 fleet. I think it has been pretty well proven that creating sub-classes only serves to weaken the overall fleet.

In my division (which I would guess has one of, if not the strongest 18 fleets right now) we will pretty much let any style of 18 come out and race whether you have a comptip or not, magnum wings, or even an SX. Unless you start to win, no one cares and guess what...the guys on stock 18s always win anyway...95% sailor, 5% boat.

By the way, I think the square top sails made by Whirlwind definitely look very modern & cool, and if I didn't race one design, I'd probably consider getting one. But allowing taller masts and open sailplans would kill the fleet instantly in my area.

sm

Author:  MUST5429 [ Wed Oct 14, 2009 7:42 pm ]
Post subject:  Re: 18 SX rule change?

I kinda hate to be the one to throw cold water on your idea.

ANY equipment rule change must be approved first by HCA-NA and then by IHCA.

I proposed a change to the equipment rule for the Hobie 18 earlier this year.

The proposed change involved allowing the use of line in lieu of wire for the trapeze.

Reasoning included the fact that spectra and some of the newer technology line is at least as strong if not stronger than wire, and easier to cut with a knife in the event that someone needed to be "freed" from the boat in an emergency.

HCA-NA approved it by an overwhelming majority, but IHCA shot us down.

IHCA is VERY protective of the whole "one design" concept. (as well they should be)
For the class association to start "officially" allowing wholesale changes to the one design policy is, even for a class as small as the H-18 SX, from their perspective, starting down a slippery slope.

The direction you are headed with your proposal would most surely be met by the same fate as the change I proposed. I would be quite suprized if it even made it that far.

I'm not telling you that I don't think you should have some fun cussing and discussing the idea, just know what you are up against before you become mentally and emotionally invested in the successful outcome of what you are trying to do.

Stephen

Author:  MUST5429 [ Wed Oct 14, 2009 7:46 pm ]
Post subject:  Re: 18 SX rule change?

srm wrote:
Quote:
By the way, I think the square top sails made by Whirlwind definitely look very modern & cool, and if I didn't race one design, I'd probably consider getting one. But allowing taller masts and open sailplans would kill the fleet instantly in my area.sm
+1

Author:  hobie18rich [ Wed Oct 14, 2009 9:36 pm ]
Post subject:  Re: 18 SX rule change?

As far as the F-18 not allowing the H-18 to race its the rules that Cross Bars must be straight.

If someone is interested in a set of conversion for the boards I.E. Tiger boards in the H-18 wells I may be able to have that done.

Author:  MUST5429 [ Thu Oct 15, 2009 3:37 am ]
Post subject:  Re: 18 SX rule change?

hobie18rich wrote:
If someone is interested in a set of conversion for the boards I.E. Tiger boards in the H-18 wells I may be able to have that done.


Rich,
I've been wondering for several years how a set of high aspect ration boards would change the performance of the original Hobie 18.

Kind of like switching a carbureted 289 over to fuel injection in a 1965 Mustang.

My brain goes in the direction of using a Tiger/20 board, and "crafting" some type of an adapter slug that fits inside the existing well of the 18 thereby adapting it to the shape of the new board.

How would you go about doing something like that ?

Stephen

Author:  MBounds [ Thu Oct 15, 2009 4:41 am ]
Post subject:  Re: 18 SX rule change?

MUST5429 wrote:
How would you go about doing something like that ?


Easiest way would be to start with a junked stock 18 board (might need two, but I think there's enough length for two "cassettes")

Cut off the top and bottom flush with the deck / hull. Gouge out the foam in the area you want the new board slot to be.

Build a fiberglass sleeve (daggerboard trunk) using a Tiger/20 board as a mold. Now you have the inner / outer shells of the cassette. Using pre-made sheet fiberglass or simething similar, build a bottom plate and a top plate. The top plate will need to flange over the top of the cassette so it doesn't slide down the trunk. Top and bottom plate would need to be fairly robust, since they're transferring the loads of the board to the boat.

After installing the sleeve and the bottom plate inside the shell of the old board, fill the voids with 2 lb density foam. Install the top plate, clean it up and you're done!

The toughest part in all of this is getting the new trunk in the right place. 18 stock boards are swept back, as are 20 boards. Tiger boards are vertical. The object would be to get the center of lateral resistance in the same fore / aft position, otherwise, you're going to have helm issues.

An interesting design/build problem.

Author:  ncmbm [ Thu Oct 15, 2009 7:12 am ]
Post subject:  Re: 18 SX rule change?

I wasn't interested in getting HCA or IHCA to approve any of this. Much like the Tiger runs one design in HCA events but also conforms to F18 box rules. So, creating something more along the lines of the F18 class rather than the OD H18 class changing their rules. In my situation for example, I have both rigs(SX and SE), I could race one design or H18 Formula depending on how the boat was set up. The last thing I want to do is take away from a successful fleet like the H18 is in many areas, in the SE the boat never makes class. What I would be interested in is creating a class that would allow H18 and H18SX owners to experiment and race without the restrictions of one design. Lets face it, the day is approaching when Hobie will no longer provide OEM equipment for the H18 and the rules of "Hobie Only" will not be applicable. Even now getting parts is becoming difficult, especially in a hurry. Last time I looked for a jib there was only one available, and Hobie didn't have it.

Again, this is not about changing the one design H18. Its about letting people that are interested tinker with their boats within a box and race them as equals. Create a box that allows any 18 foot boat to comply. I have no idea how to do this but would be interested in being involved. I have really enjoyed making the changes to my boat and the performance difference is noticeable.

On the daggers, the method illustrated would surely work but my approach to this will allow conversion back to standard boards if desired. I have the junk boats to work from as well. I would prefer two plugs, one for the top and one for the bottom that are pulled together into the well. The plugs can be solid which will provide the strength for the transfer from the dagger to the hull. The placement of the new board is the part I have no clue on. My initial thought would be to place it as far back in the existing well as possible but that may create helm issues. Perhaps placing them in the exact position from the transom as the Tiger is the answer. I will begin playing with this idea early next year after I get some other projects out of the way. Any other thoughts on how to do this? Board placement ideas?

Author:  MBounds [ Thu Oct 15, 2009 7:59 am ]
Post subject:  Re: 18 SX rule change?

ncmbm wrote:
Any other thoughts on how to do this? Board placement ideas?

Find the centroid of the stock board / Tiger board projected areas below the hull. Position the Tiger boards so that the centroid is at the same fore/aft position as the stock board.

That's a starting point. On foils (especially high aspect ones like the Tiger's), the centroid is not necessisarily the center of lateral resistance, but it's close.

Easiest way to find the centroid (without resorting to calculus) is to cut out the shape in stiff cardboard and balance it on a pencil.

Author:  srm [ Thu Oct 15, 2009 9:20 am ]
Post subject:  Re: 18 SX rule change?

I have no idea how you'd achieve what you're talking about either. Now you want to include any 18 foot cat in the mix...

If there's an F18 fleet in your area, I'd just ask to race with them (or just show up). Sounds like what you really want is for the (wingless) SX18 to be considered F-18 compliant. While I'm sure you'll never get the international F18 rules committee to change the rules, I'd bet you could at least race at a local level - most regattas are happy to take your money.

As far as the dagger boards are concerned. I think an insert would be doable. An even more simple approach might be to mimic the Hobie 20 which has daggerboard wells that are quite oversized and lined top and bottom with a heavy carpet to conform to the board. You could probably get away with something as simple as that at least for your experimentation period. As far as fore & aft positioning, I'd keep the point of maximum camber (apex) of the boards lined up at least as a starting point.

sm

Author:  MUST5429 [ Thu Oct 15, 2009 11:29 am ]
Post subject:  Re: 18 SX rule change?

srm wrote:
As far as fore & aft positioning, I'd keep the point of maximum camber (apex) of the boards lined up at least as a starting point. sm


One problem, ( as I see it anyway) is that the 20/Tiger Boards are almost strraight up and down, while the Original H-18 Boards are canted back with a bit of rearward rake.

As you engineer the "adapter", or the "plug" do you have the new board lift straight up and down, or do you cant it rearward just as the original board is canted.

My inclination would be to engineer the plug so that the new board lifts straight up and down.

If you are close to center of effort with your first try, you shouldn't have too much of a "helm" issue, and even if you do, you might be able to adjust mast rake to relieve any "Helm issues".

I've got a handful of old H-18 daggerboards, I may take the worst one and start marking and cutting.
All I need now is some old H-20 daggers. and the time to actually take a run at something like this.

It would be some fun, but have very limited use for a guy like me that lives to class race.

Stephen

Author:  ncmbm [ Thu Oct 15, 2009 12:09 pm ]
Post subject:  Re: 18 SX rule change?

srm wrote:
Now you want to include any 18 foot cat in the mix..


Anything that isn't already F18. That could include the roto boats as well. The F18 rules apply to any 18' boat with flat beams basically. Many of the older NACRA designs fit into this box, the H18 is one of the few that doesn't.

srm wrote:
If there's an F18 fleet in your area, I'd just ask to race with them (or just show up).


I already do this, they wouldn't allow it with the stock jib. I run a Tiger self-tacking jib now so that eliminated the argument. My modified 18 does not compete well with the F18. It goes up wind with similar speed but the effect of the lift the F18 daggers create is very noticeable. I have several issues I would need to correct for it to play well with the F18s, many of these I am slowly working on. One of the biggest things I have found is the jib set-up. The Tiger bridles are closer to the front crossbar than the H18 which sets my jib further forward leaving a rather large gap between the leech of the sail and the mast, this creates turbulence which may be enhanced under spin. With the Tiger main the mast needs pre-bend, the H18 spreaders and diamonds were not intended to pre-bend and do a poor job of it. So to think my boat in its current state can race with F18s is incorrect.

I'm just chasing the thought that Skipshot brought up. There will be more and more H18s without Hobie produced sails in the future, the hope of continued one design racing most surely will perish as the remaining boats age. IMO the only way a discontinued boat can go on is with a open manufacturer policy, a formula that the boats must conform to.

Author:  Skipshot [ Sat Oct 17, 2009 12:46 am ]
Post subject:  Re: 18 SX rule change?

Nothing like proposing a class rule change to spur a discussion, but my crack in the other thread was not meant to be taken seriously since, as the above discussion shows, changes to either the one design rules or design modifications of the 18SX to comply with F18 rules and be competitive become fruitless.

Some boats are just doomed to class racing oblivion. The best hope for the 18SX with a pentex square top in my area is racing in open class multihull regattas or accept the original intent of the boat as a recreational good time. Even if rule changes were allowed the question remains if the rule changes would inspire H18SX owners to race, and if they did what would their numbers be? As far as I know there is only one other 18SX in Division 3, and the owner doesn't race it and recently listed it for sale.

One of the reasons I did not convert my SX to an SE is the lack of a strong 18 SE class in my division combined with the cost of the conversion. While I could find a used mast for a bargain I would need/desire new standing rigging and new sails, which would put the conversion cost near $2000, and then I'm in a class which consists locally of three other boats, which is hardly a reason to make the investment. If I were to become serious about racing I would go F18, but only after I dropped about 50 pounds.

I've made my peace with Hobie's one design rules and would not expect the IHCA to make an exception for an uncommon and discontinued boat.

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