Can we talk about this single control line rule? It seems to me that this will work well upwind, but on initial view it seems we may end up with quite a bit of twist off downwind. If that were correct, this would mean that we are no longer sailing to VMG downwind.
What am I missing? what is your plan?
What am I missing? what is your plan?
You're missing a previous post (buried somewhere back there!) when Wouter mentions a traveller system using Ronstan RF188 becketed blocks and a 4mm control line.
You are correct.
But while this issue has not been discussed publically yet (except for the traveller setup) as solution is worked out anyway.
There are two versions : one uses a kicking strap (non-adjustable) and the other uses a ram vang (non-adjustable)
These have a use upwind as well. By preventing the mast from bending back too far when the mainsheet is released the sail should tack better in lighter winds. Additionally this limiter prevents the boom from rising beyond a certain level and thus reduces twist when the sail is fully boomed out.
But for most course John is right the F12 will have a traveller system, one that only costs 37 Euro's in DE-LUXE version and 4.5 Euro's in the cheap but effective setup. this will take of most needs All the way up to reaching a little deeper then a beam reach.
It is many more things but I'm not going into detail on this here and now.
But I can assure the readers here that teh basic idea is to give the F12 significantly more performance then the alternatives out there (like the wave) by providing much better sail control. The only limit to this is cost but even the DELUXE version costs less then 200 bucks overall. While providing full control in light, medium and heavy winds with draft control devided in lower halve and top halve and twist control for both the light and heavy winds.
Pretty much the design goal I had was this :
Light winds :
relatively shallow draft in the sail with alot of twist along the leech.
medium winds :
10-15 % draft in the sail with a tight leach. Here the mainsheet mostly controls draft in the sail and very little twist.
heavy winds :
shallow draft in bottom part of sail with almost no draft in the top and a leech that is twisting off. But with the behaviour that releasing mainsheet first increases twist and hardly any draft. If possible releasing the mainsheet should first increase draft then allow the boom to swing out and only in the later stages allow the draft to increase.
I think I got that worked out to a large extend.
Wouter
Is a windsurfing rig still in consideration for the F12? If you take a modern windsurfing rig and pop it into that welded bracket as shown on the land sailor...all the tweaking is done when you rig up the sail at the beach...other than maybe a traveler...and the main sheet what else is there left to do? I am really excited to see what a modern windsurf rig could do on the F12...IMHO the windsurfing rigs (sails/mast/boom) are light years ahead of the sails the catamaran community has in use.
The interplay between the sail cut/mast flex/boom stiffness
makes the windsurf rig feel alive. I would go so far as to say that most boat sailors would wet themselves if there boat had the 1/2 the gust response a well tuned windsurfing rig has. A gust hits and its just pure forward acceleration.
...ask anyone who windsurfs at a near expert level (short board) who is also a cat sailor... they will confirm this.
Regards,
Bob
Allow me to respond to this question in a short to the point way :
-1- What do windsurfer do when the wind changes in strength ?
-2- How many suit of sails do windsurfers have to be able to sail whenever they want ?
-3- How well does a windsurfer transition from pure upwind work to downwind with high vmg ?
Correct me if I'm wrong but the windsurfer rig may be lightyears ahead of catamaran sails, but only at a very narrow windstrength band and with only a narrow band of courses.
Maybe somebody should educated me on Formula surf boards, I hear they do better ?
But it is often forgotten that a sailboat rig is required to operated well at a very wide windspeed range and on any course between pinching upwind and runnin square downwind.
Sailboat rigs can sometimes have amazing flexibility in flying shapes produced by adjusting a few control lines while racing on the water. I haven't seen surf board rigs do anything like that.
Am I wrong ?
Wouter
Hi Wouter
“1- What do windsurfer do when the wind changes in strength?”
They use to have to change sails every 6 mph or so…now you can go out with a top quality sail and hold it down in wind that would have required 3 or 4 sail changes 15 years ago.
“-2- How many suit of sails do windsurfers have to be able to sail whenever they want ?”
I use to have an 8.0/7.0/5.7/5.0/4.5/4.0/3.5/3.0 in the late 80’s that would let me sail from 5mph to 40 mph winds. But the 5.7-3.0 were for surf sailing…where it is much more important to be dialed in with the perfect size. Back then just for recreational flat water it would be more like 8.0 6.0 4.5 Today you could easily hold down a good race 8.0 from drifting conditions to well over 25 MPH wind on flat water and the proper board. Basically all the conditions that catamarans are regularly sailed in.
The cut of the sails and the way they have tweaked and tweaked the sails and sail mast interaction is just amazing.
3- How well does a windsurfer transition from pure upwind work to downwind with high vmg ?
That’s a function of the board shape (rocker/bottom shape/rails) and fin being used as well as the sail itself. Dead down wind is not its fastest point of sail but sailing powered up on a deep broad reach will get you downwind at break neck speeds for sure.
“Sailboat rigs can sometimes have amazing flexibility in flying shapes produced by adjusting a few control lines while racing on the water. I haven't seen surf board rigs do anything like that.”
My Friend Mike Gephardt three…(or was it four?) time Olympic sailboard campaigner (one silver, one bronze) has had adjustable outhaul and downhaul on some of his race boards that I have seen to address just the things you are proposing…
Please don’t take my enthusiasm for windsurfing as a knock on catamaran sailing…I love them both…it just that windsurfers has been so much more open to new development than boat sailors. So to have a chance to take what I feel is a vastly more developed rig and apply it to a catamaran gets me all excited.
One lesson that windsurfing surfing seemed to grasp right away it that everything is interdependent…and although that sail design might not have worked last year, it works great this year because the board is been refined to capitalize on the sails strength or the fins improved which allowed the sails to be cut flatter and still have the power to plan out quick…or that setting on a softer constant curve carbon mast allow the sail to breath with every puff but reset to its static shape much more quickly. Large square head sails with tons of downhaul that allowed sails to triple there designed wind range. Its not that Cat sailors are unaware of this, it just that the windsurfing community has put more a lot more energy into R&D . Every variable affecting every piece of gear was/is on the fast track so that it just keeps getting better and better at an accelerated pace.
On the other hand most Cat sailors seem to put “protecting their investment” over any desire to propel the sport to the next performance level. Every possible improvement is seen as a threat of making their cat obsolete.
Shake loose some of the cobwebs and fire up some cat sailors to consider something beyond the status quo…LOL..push the limits till they squeal like little girls. I can’t wait to see were we end up.
Best Regards,
Bob
That is a very true observation in my opinion. The cost of cats is much higher than windsurfing, so it is understandable tough. Balancing cost vs development is a very fine act of performing on a slack line, with entrepreneurs trying to find loopholes in the ruleset all the time. A different view on the same problem would be
do we want the sailor with most money to win, or the best sailor
. The answer is usually trying to control development, so it happens slowly and in increments. Not in large jumps rendering lots of boats obsolete and uncompetitive. And what about spending money on the latest
hype
, just to discover that it did not make you any faster <img src=
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The C class is an example of an class which nearly have developed itself into extinction by not limiting their development over the years. Those rigid wings are drop dead sexy, but wildly impractical for club racing.
I'm not ruling out windsurf rigs and that has been my personal opinion from the beginning.
As the situation stands a windsurf rig can be fitted to the F12. I see no need to forbid it.
Still the designing I've done so far does not enclose optimizing a windsurf style rig. The reasons for this decision are as follows :
-1- Cost limitations
A class 5 mast can be homebuild by an absolute amatuer.
-2- Sail efficiency.
A sailboat rig at this time can have a significantly higher aspect ratio then the windsurf rig.
I'm not sure that the current lower aspect surfer sails can easily be scaled up while retaining their excellent behavior.
-3- A cat is significantly different from a surfboard
In my experience a catamaran has a much lower need for gust response then both skiffs and sailboards. Having the sail respond to a gust while it is not necessary means losing performance. At this time I feel a more conventional catamaran rig is more suited to getting optimal performance over the full range of conditions from light to strong. It not about holding a sail down in all conditions, it is also about getting maximal performance in all of these conditions.
-4- Windsurf sails don't really have a mainsheet system that affects the leech tension.
In affect with a more conventional rig you have one extra tuning control. With f12 you have two more as the traveller setup can be set to windward (something normal cat traveller systems can't do).
-5- I'm personally not experienced in windsurfer sails.
I understand catamaran sails to a large extend and surf sails to a much lesser extend. In effect I do what I know best. Maybe somebody else needs to do the design work involved with F12 windsurfer sails ?
But again these are not reason why the surf rig is disguarded (it is not), they are only reasons why I'm not developping it further as opposed to the class 5 landyacht based rig.
But if anybody else wants to spend some time on this I'll be very interested to hear the results.
Wouter
I am trying to persuade a windsurfing school and a holiday company to test my current boat, which has a biplane windsurfing rig setup, both these companies have experienced dinghy and windsurfing sailors on their staff. The feedback should also apply to F12 windsurfing rig setup. I am hoping to get a better understanding of which sails work best. I will share the results with group.
Gareth
That'll be great thanks.
Wouter
“-1- Cost limitations
a class 5 mast can be homebuilt by an absolute amateur.”
>If you are talking about a new carbon mast, I would have to agree with you…but there is a lot of used equipment on the market…especially now that kite boarding has taken off and a lot of windsurfers have made a switch…at least in my area.
“-2- Sail efficiency.
A sailboat rig at this time can have a significantly higher aspect ratio then the windsurf rig.
I'm not sure that the current lower aspect surfer sails can easily be scaled up while retaining their excellent behavior.”
>The windsurfer rigs have been all over the place in respect to aspect ratio, but have settled into the sweet spot about twelve years ago after trying all the extremes, including much higher aspects than are available in the current offerings.
>For a while they felt that longer boom length with lower aspect was needed for low end power, and then went to extremes with high aspect for speed sailing to “reduce drag”. In the mid-eighties Gastra sails came out with “camber inducers” to force an air foil shape into the sail which gave a lot of stability to the foil of the sail…particularly noticeable in larger sails when sailing thru a lull, and building on the use of full length battens and the RAF (rotating asymmetrical foil) shape sails that Neal Pryde was offering at the time.
>Fast forward to the nineties… the sails went to monofilm and the cuts became better. Centered on a flexible yet quick resetting carbon mast (which allows the sail to maintain its ideal design shape a larger percentage of the time) with very stiff carbon booms (outhaul stability, if the boom flexes the sail draft increases and moves back…now you are looking at a “face plant”)
>Windsurfing moved away from the pin head sails and started putting more and more area in the head. By using a large square top design it allowed them to put more area in the sail for power to get up on a plane sooner as well as lowering the wind speed necessary to plane in the first place. The older style sales (especially in the larger sizes) quickly got out of control… but these new sails were cut flatter and were designed to have a complexly floppy leach at the top 30%+- of the sail. As the sail powers up, the top of the sail twists off and the draft (power center) moves down and forward…turning a gust into pure forward momentum. So they achieved a “best of both worlds” scenario. More sail area for light winds and a “self regulating” sail in high wind or gusty conditions…When properly tuned it’s like an automatic transmission for your car.
“-3- A cat is significantly different from a surfboard”
>I agree…this is where it could get interesting…to see if they are as different as they appear…
“Having the sail respond to a gust while it is not necessary means losing performance.”
>Again I agree…but at least when used in conjunction with a properly designed sailboard the sail design has been so dialed in that there is very little wasted energy. What would have blown you over, or caused a draft shift to the rear of the sail causing an “over the handlebars” situation in the past now gets converted to pure forward power and very balanced feel.
“At this time I feel a more conventional catamaran rig is more suited to getting optimal performance over the full range of conditions from light to strong.”
>That may prove to be the case, but we won’t know until it is seriously tried…the possibilities are exciting if the positive attribute will transfer over to the f12.
“It not about holding a sail down in all conditions, it is also about getting maximal performance in all of these conditions.”
>”Holding down the sail” was more in reference to the idea that, as in the past, windsurfers are forever changing the size of their sails to meet the changing wind conditions…I might add most catamarans are doing little more than “holding it down” in 25mph wind wouldn’t you say?
“-4- Windsurf sails don't really have a mainsheet system that affects the leech tension.”
While you are correct in saying that they don’t have a mainsheet system that affects leach tension… The outhaul tension, in conjunction with the down haul controls the leach tension to a very fine degree. Top of the line windsurfing sails are extremely “tunable”. This is generally done on the beach, however as I stated in my prior post some racers have used “on the fly” outhaul and downhaul adjustments to give the sail a fuller shape when course racing on downwind legs.
“I understand catamaran sails to a large extend and surf sails to a much lesser extend. In effect I do what I know best. Maybe somebody else needs to do the design work involved with F12 windsurfer sails?”
>I would have loved to be more deeply involved in this aspect of the F12 but family/business restraints have my plate overflowing…that said…any experience I have in this area that can be of help I freely offer…
>One of the coolest things about the windsurfer rig is… if can be set up with a way to accept a standard windsurfing mast base, you can try an endless variety of sails by just releasing the spring clip and snapping another on.
>Most serious sailors have a whole “quiver” of sails of the same brand and style, so you could see exactly how far to push the size limit before it became a point of diminishing returns. Same way with sail shape/style.
>It might be worth approaching some of the top windsurf sail manufactures, or a local windsurfing shop to see if they might want to become involved by offering sails/masts/booms/bases for the prototype in exchange for advertising exposure. I am sure they are feeling their revenue fall off drastically as Kite boarding as taken a big bite out of their market. Might be an easy sell with the prospect of opening a new market for their equipment… Wouter… with your track record with the F16 Class you might have the credibility to make that happen…
Regards,
Bob
All very interesting. Should be tried I agree.
Talking about plates overflowing ... I know another guy who is in desperate need to make a few difficult choices.
If I did have the financial resources at this time I would have a set of F12 hulls made for me and then would do the first test sailing myself using my landyacht gear and the ruddersetup of my F16.
But I don't have sufficient funds at this time and I really don't have time (this year) to build the hulls myself.
With this situation it will be impossible for me to try and get the local windsurf guys to give it a go. For that to happen I need to at least provide them with a test platform. Also as a proof of seriousness/dependability.
But I do have a network and maybe I should do the rounds and see what I can arrange .....
Wouter