Asymmetrical Spinnaker Setup

Moderator: GreenLake

Re: Asymmetrical Spinnaker Setup

Postby prochase » Fri Jul 31, 2020 11:49 am

Quality is good. 3/4 ounce with all the normal attributes associated with an A-sail. Sets well and trims well.

Eric
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Re: Asymmetrical Spinnaker Setup

Postby AndrewB » Mon Sep 21, 2020 6:15 pm

Shagbark wrote:Andrew and Prochase,

Did either of you purchase the UPS/Drifter/Asymmetrcial?


I ended up buying two sails--a drifter (used, from Masthead) and an asymmetric spinnaker from Quantum Sails in Dallas. I am pleased with both. I paid $133 (incl. shipping) for the drifter and $400 for the spinnaker.

The drifter will sail closer to the wind than the spinnaker since its shape is flatter and is basically a big, lightweight jib. The spinnaker is even lighter weight and adds a big boost while reaching. It also looks cooler (got mine in red, white, and blue)! The spinnaker is more technical to sail, and I wouldn't cleat it whereas I would feel pretty comfortable cleating the drifter like a normal jib.

Here are the prices I got earlier this summer:

Doyle UPS $1008
Doyle APC $1080
Peak Generator $348
Peak Asy. Spinnaker $564 (may not include Prochase's 20% discount)
Precision Genoa $388
Precision Asy. Spinnaker $636

Doyle and Precision were based on custom quotes; Peak prices were pulled off their site. All were operating on a 3-6 week lead time. Quantum was able to turn around the spinnaker for local pickup in Dallas in about 3 weeks. Getting to meet the sailmaker, see the loft, and talk sailing would've made the deal worth it, and saving $600 vs. Doyle was icing on the cake.

I opted to avoid a bowsprit just to reduce complexity (I sail with my young sons, and less is more). This created the need for some creativity to avoid jamming my jib furler. Happy to snap some photos if anyone is facing the same issue.

One thing I'm considering improving is the rigging. With all my turning blocks in place, it only adds a few minutes to rig up. But if there are any ideas out there for reducing this time, Id' love to hear them. I have a friend with a Flying Scot whose spinnaker sheets are under the deck with through-deck turning blocks. Looks nice and eliminates the need for additional rigging prior to setting sail. Maybe a winter project?
AB
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Re: Asymmetrical Spinnaker Setup

Postby GreenLake » Mon Sep 21, 2020 7:16 pm

What are the luff and foot sizes for your sails?
~ green ~ lake ~ ~
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Re: Asymmetrical Spinnaker Setup

Postby tomodda » Mon Sep 21, 2020 7:22 pm

Masthead drifter? Have you flown it yet? I know drifters are for VERY light winds, but I'd fear the forces on the unstayed mast length of mast... As it is, the last few feet are like a big aluminum noodle. I think the leech tension on the main, along with thoughts and prayers from the entire staff of Ian Proctor Metal Masts Ltd. are the only things holding it in place. And how do you tack it around the forestay without a bowsprit? Up on a pendant (short length of rope at the clew)? Or are you planning to roll it in/out on a furler on each tack? I've even seen folk simply jibe around a drifter (let it fly forward). Anyway, I'm very curious, please excuse all the questions. Would love to hear more about your drifter.

Tom
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Re: Asymmetrical Spinnaker Setup

Postby GreenLake » Mon Sep 21, 2020 7:47 pm

At 14 knots apparent wind, sails experience about one lb of force per sqf.

If a masthead drifter has a foot of 10' the area should be roughly 100sqf for a 20 foot mast. If you use that beast strictly under 7 knots of apparent wind, you would get 25lbf of total force. Due to geometry, the sideways force on the mast head should be even less (with a staysail, the tack is not on the mast, so it can assume some of the sideways force without loading the mast).

I needed 300lbs at 3-4 feet lever to bend my mast (when straightening it) that's more than 900 pound foot. At 6 feet of unsupported mast at the top you may need 150 lb of force to bend the mast. That might give you enough of a safety margin - you decide.

I bent my mast on a day with max 10 knots wind (at least, that's my recollection); with force going at the square of speed, it should have resulted in rig forces of about 1/2 pound per sqf or 75 pounds with say, the center of effort 10 feet up. That would make 750 pound foot at the partners because my stay had come loose, not that different from the 900 pound foot it took to bend it back).

Anyway, those would be my back of the envelope guesstimates, which I would assume a sailmaker figured into the calculation.

Key would be to not use that drifter that far out of its wind range. Wonder what instructions the sailmakers provided?
~ green ~ lake ~ ~
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Re: Asymmetrical Spinnaker Setup

Postby tomodda » Mon Sep 21, 2020 11:10 pm

Yeah, 7kt max wind sounds about right. Even on full-size masthead rig boats, it's about the same, since these sails are usually made of 1.5oz nylon. You CAN fly it in more, but you'll quickly get a blown sail. But, all this talk is making me miss my old Quarter-Tonner!

Well, not really, that boat was a cranky beast...
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Re: Asymmetrical Spinnaker Setup

Postby Alan » Mon Sep 21, 2020 11:41 pm

I'm thinking "Masthead" is this company,

https://mastheadsailinggear.com/

not that the drifter is flown from the masthead. That would be problematic, I imagine. My roughly 3/4-height Doyle UPS bends the mast forward easily if the halyard is overtighened. And just for reference, my mast is a Dwyer DM-284, not a bendy Proctor.
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Re: Asymmetrical Spinnaker Setup

Postby AndrewB » Tue Sep 22, 2020 5:52 pm

tomodda wrote:
Alan wrote:I'm thinking "Masthead" is this company,

https://mastheadsailinggear.com/

not that the drifter is flown from the masthead. That would be problematic, I imagine. My roughly 3/4-height Doyle UPS bends the mast forward easily if the halyard is overtighened. And just for reference, my mast is a Dwyer DM-284, not a bendy Proctor.


Alan is correct--Masthead Sailing Gear out of Florida. They sell used sails, and I came across a Drifter that looked like it would fit the dimensions and happened to be manufactured by Spindrift, same as my DS1. Wasn't particularly considered about having brand new sail since I just wanted to try out something different.

When jibing, I let the sail fly off the front of the boat and then sheet in from the other side. Works fine except I found that the lazy sheet had a tendency to get hung up on the stemhead and jam the tack block into jib furler (since I don't have the natural separation a bowsprit would create). I attached the tack block to an eye strap (rated to 1000 lbs) forward of the stemhead, and that has solved the jamming problem.

Sail dimensions:
Drifter: Luff 14'9", Leech 15'1", Foot 8'10", LP 8'7" (1.5-oz Nylon and has a luff rope w/snaps)
Asymmetrical Spinnaker: Luff 15', Leech 13'6", Foot 10' (.75-oz Nylon, cross-cut)
AB
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Re: Asymmetrical Spinnaker Setup

Postby Shagbark » Mon Dec 21, 2020 7:26 pm

AndrewB, can you supply the contact information of the loft you used for your asymmetric? I looked for quantum sails out of Dallas and the closest one I could find was Houston.
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Re: Asymmetrical Spinnaker Setup

Postby Newbflat » Sat Jul 23, 2022 9:30 pm

Now that a little time has passed can anyone compare and contrast the UPS with the Peak Generator? Can or should you fly the Generator on a small sprit? I’m looking for a light air reacher and I’m not quite sure if the Generator is a Code 0 or just a big free flying Genoa?
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Re: Asymmetrical Spinnaker Setup

Postby tomodda » Sat Jul 23, 2022 11:19 pm

Hi:

I've not flown either sail, but have done plenty of daydreaming, scheming, research, and pricing on the question of a larger, light air foresail. TLDR Conclusion: Stick with the Sym Spinnaker if you have one and otherwise enjoy the ride on the main and small jib. Answering your questions and explaining my conclusion:

1) The term "Code 0" is very loose and undefined. For a racing, code zero for monohulls is often restricted by rule to a mid-girth of at least 75 percent of the foot length and a leech that is no more than 95 percent of luff length. Since both sails are illegal for DaySailer racing, it's a moot point. There's been some rules discussion about allowing Asyms, etc, but the idea is always shot down. It goes against the ethos of keeping Daysailers relatively cheap and accessible for racing - which I heartily agree with. We don't need an "Arms Race!" Anyway, for cruising, there is no real definition of Code 0, so both the "Generator" and the UPS kind of are Code 0's, why not? By the way, both "Gennaker' and certainly "The Generator" are just marketing terms.

2) The UPS is for angles further downwind. The Generator is a reaching Spinnaker or full cut Genoa (take your pick how to describe), for higher angles. I believe it's cut at 165% of the fore triangle and it's luff is free (not hanked to a forestay). The Generator needs a pole to go deep downwind. I don't think that the UPS does need a pole, but it needs a bowsprit to hold it out ahead of the forestay.

3) The UPS is a fractional sail, at least on our boats, so essentially a pole-less (I think) Spinnaker. The Generator is a masthead sail, so you both have to rig another halyard and keep a close eye on your mast bend. Too much wind and that Generator will pull your unsupported masthead forward or to the lee (depending on your angle of sail) with untoward consequences to your mainsail trim.

Which brings us to my own ideas for a "Daysailer Drifter," which would be a crosscut, 155%, masthead "Drifter Jib" sewn out of 1.5oz nylon. With Dyneema for the luff rope (free flying luff), you can use luff tension to move your draft around for upwind or down. The problems with this fantasy were quickly apparent: A) gets crowded up at the masthead and down at the stemhead B) bending the masthead - wouldn't damage the mast, but would screw up the sail shape enough to lose any of the advantages of this rig. C) COST! Holy cow, my sailmaker quoted me a price nearly as much as my jib and main combined! Ripstop Nylon is EXPENSIVE, and anything else will soon be blown out. Not to mention a new halyard block, stem downhaul rig, turning blocks, cleats, etc.

Hence my TLDR conclusion - *IF* I was actually cruising the boat, where I might spend all day or a few days in very light air, then sure, might be worth it. If it's just my usual knocking about on the lake and the wind dies down, I just can't see the value of ghosting home at 2.5 knots instead of 1 knot. Ghosting is ghosting, and I DO enjoy the mental challenge of it. But if I'm in a hurry to get home, I'll just fire up the engine.

As it turns out, these drifting sails are indeed mostly marketed to long distance cruisers (where an extra knot makes one hell of a difference!) rather than daysailers of any ilk. Racers are another story, depending on the class and race they are limited not only on what sails they can carry but also how MANY sails they can carry. Mini-Transats, for instance, are only allowed 7, of which one is the storm-job, so really only 6 (including the main). So one can see how a "multi-talented" Code-something hybrid foresail becomes very attractive. But for "round-the -buoys" beer-can sailing? Notsomuch, unless you are sailing with full crew, unlimited money, and the rulebook permits. And even then, not much of a difference, after all EVERYONE will be sailing the Code-Whatever, so what's the point?

Anyway, I don't mean to rain on your Drifter Parade, just sharing my thoughts on the whole subject. And who doesn't love a good "Whomper?" Put up the Whomper! ;-)
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Re: Asymmetrical Spinnaker Setup

Postby Newbflat » Sun Jul 24, 2022 10:15 am

Interesting take tomodda. Well, I don’t have a spinnaker and live in a place with a lot of light air in the summer. This week if you want to go sailing in the central Puget Sound you better have a big head sail or you will not be going very far or fast. It has been in and out of ghosting conditions lately and it’s likely to stay ghosting to light all week. Typical nice summer weather in Seattle. I share this boat with a good friend and we want it to be a sporty (for a daysailer) beer can racer and family cruiser as needed. At the moment we are not interested in class sailing so are not worrying about it. But I do like moving along in near drifting conditions so it seems smart to have a larger headsail oriented towards those conditions. Personally I would be interested in a headsail that I can close reach with in light air and works ok off wind. I’m ok sacrificing some down wind for a little up wind. This sounds like how the UPS is billed as it will sail something around 45° apparent in light air (I read) and thats very appealing. We are fine with making a bow sprit to run one efficiently and fully understand the extra jewelry needed to rig and run one. But it leaves me wondering about other similar sails by other manufacturers, the UPS is a chunk of change for sure. I’m surprised to hear the Generator is a mast head sail. I see no reference to it being so anywhere. That would make me nervous for a number of reasons. Although maybe you could rig and run it like some old gaffers where they would take their topping lift and run it to the aft windward quarter to act as a running back if the didn’t have any installed…. Lol, maybe above the scope of the boat. Anyway, we want a headsail to take advantage of the light summer winds here in the sound and I’m trying to sort out what we need. Any first hand experience out there with a Generator would be helpful.

We are pretty dedicated sailers and would prefer not to turn on the motor if we don’t have to. The difference between drifting at 1 knot or 2.5 knots is getting to the slip in an hour or 25 min… not insignificant at all.
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Re: Asymmetrical Spinnaker Setup

Postby tomodda » Sun Jul 24, 2022 10:52 am

I hear you.... although I'm an East Coaster, I've have sailed out of Gig Harbor before, and into nose-range of the Aroma of Tacoma ;-). Was a light and fluky day, but beautiful. Sorry that I'm not more help re:the Generator or UPS. If I were pursuing it, I'd seriously consider a mast-head sail with some sort of swappable running backstay arrangement as you mentioned. Again citing Mini-Transats, they rig a backstay to each corner of the transom and then slack the leeward one enough to swing the boom past it. All depends on your tolerance for extra fuss/extra cost/extra things to go wrong. Here in the SouthEast, my season of guaranteed drifting conditions - Summer - is so hot that it's insane to go out and even attempt to sail. Near heat-stroke just rigging the boat at the ramp. I'll sometimes putt-putt her mastless over to a secluded swimming beach, otherwise I pray for cold fronts!

Best,

Tom
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Re: Asymmetrical Spinnaker Setup

Postby GreenLake » Sun Jul 24, 2022 8:32 pm

The potential advantage of an asymmetric sail might be that it presumably sets better in the lightest airs than a symmetric spinnaker. I haven't used one, but I'd imagine the usual trick of heeling to leeward would work even better than for a symmetric sail. But if that's not the case, I'd love to know.

My conclusion after reading along here over the years is the UPS as configured by KC Walker could be a winner. He rigs his on a short sprit and on a furler. He also doesn't do masthead but goes only a bit above the hounds. That still puts a bending moment on the upper mast, but the lever arm is so much shorter that it isn't as much of a concern. Both from the strength of the mast and from effect on (upper) mainsail trim.

And it seems to me that unless you use a tack line, a furler is the only realistic option; you aren't going to want to go on the foredeck to switch between an asym and jib. Also, in my experience, days where I can get both absolute calm and fairly strong winds are not as rare as you might think.

It is pure accident that one of may favorite cruises (and so far among the longer ones) tends to have a DDW return. Which is one of the reasons the symmetric spinnaker has served me (reasonably) well.

Admittedly, I've also shied away from adding a sprit, even a removable one. So far, at least.
~ green ~ lake ~ ~
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