assy sizing

[AlanH]

Two separate teams of guys with tons of experience in my boat have suggested that since there's no One Design on SF Bay, I should be moving to an assymetrical spinnaker. I have doubts. S2 7.9's don't plane. They'll surf off the front of a wave but at 26 feet long and 4500 pounds, these are not surfing machines. They were designed and built to edge out J-24's and be a bit more cruisey down below, as well as trailerable.

Well, if I can find a used assy that's more or less the right size, I might buy it and try it out.

Headstay length on my boat is 31 feet, eight inches.
J is 9 feet six inches.

I'd probably make an aluminum sprit with a bobstayto try this out with, as I have a buddy who can weld aluminum and the materials are cheap. The boat already has a bow eye. I figure that the length from sprit-tack-point to hounds will be about 32.8 feet, plus or minus a few inches. Assuming that I get the tack 2 1/2 feet out in front of the stem, that makes J-asp about 12 feet.

The mainsail is really the engine on this boat so I'd be fine with a 165% chute, but for trying it out, I'll take whatever.

My question is, with that information, what size assy should I be looking for? I want an "all-arounder", though to test it out I'll take whatever I can find/beg/borrow. I assume it should be something with a luff about a foot longer than that 32.8 feet....so something close to 34, but heck if I know.

 

[BobJ]

Based on the 32.8 feet you could go a bit longer than 34 for a true runner (A2), maybe as much as a 37' luff, especially if the sprit was longer. My smallest runner is 39.6 on the luff so that won't work.

The stock bow eye on the 7.9 appears to be too high to give you enough leverage for a sprit. Rags' bow eye is at the waterline, although I only need the bobstay for the Code 0. If the sprit is installed securely you may not need a bobstay for a running kite.

Jonathan and Christine went through this with their Laser 28 - you might check with them.

 

[AlanH]

On a cruising multihull forum, I read that they pick assys to be about 1.03 x "tack to hounds length".

for me that would be 1.03 x 32.8 = 33.8


--which strikes me as too short. I suppose even cruising multis push their apparent wind forward a fair bit. Yeah, this will be a broad-reacher and runner, mostly. I'll look around for something in the 35 foot range.

Elsewhere, for cruising, I read 106-108%

1.08 x 32.8 = 35.4


I'll have to have either a deck-mounted sprit or an A-frame. I'm horrified at the cost associated with the 3 carbon-fiber A-frame sprit systems I've seen. C- Sprit, Trogear and now the third one is slipping my mind. I can't spend an extra $1,000 to save four pounds. I can build a perfectly reasonable 3 foot A frame sprit from Aluminum for $80-90 worth of materials...some bolts, and $100 to my buddy Len for some welding. I might even go get it powder-coated black for that sex-appeal effect if it all works out.

Bob, the bow-eye on the Wildcat is about 2/3rds of the way down the stem...it is a bit too high, but should work OK for trying it out. If everything seems good, then I can plug those holes, fair out the "dock chew" marks on the bow and relocate it a few inches above the waterline.

 

[BobJ]

Alan, have you looked here? I see a couple possibilities.

Used spinnakers at Pineapple Sails

 

[AlanH]

Alan, have you looked here? I see a couple possibilities.

Used spinnakers at Pineapple Sails

I did...these two were likely candidates..

# luff leech foot midgirth sq ft struct $ material
1239 33.65 30.70 20.35 19.50 527 ASSYM/BLU&WHT/LIKE NEW 9 $800 0.75 FIRM NYLON
1183 37.60 35.60 24.70 19.85 635 ASSYM/RAD'L HD:RD/BLK/YLO 5 $750 0.75 NYLON


1239 seems pretty good but it's a scooch short on the luff. Then again I could always just ease the tack line about a foot. What say about that idea? I have no idea, literally the only time I've flown an assy was on two midwinter races on Rags in the Estuary about 4-5 years ago.

1183 might work but "radial head" means straight panels at the tack and clew, right? Also, the midgirth and foot are enormous for my boat! My usual J is 9.5, so 180% of that is 17.1 . This sail is 260% of LP! whoooiiie.

 

[Tchoupitoulas]

Do you know what the hit to your rating will be?

 

[Henry D]

I got -3secs for the bowsprit exceeding JSP by 24"
Regarding your bowsprit, I can have something for you if you don't mind some scratches
you can shoot me an email: [email protected]

 

[AlanH]

Henry, your Trogear product is freaking brilliant, especially the way you mount it, but this is a $5,000 boat, into which I've now invested about another $5,000, $6700 if you include the haulout and and ignore the hoisting sling that I can't use unless a certain real estate developer either gives up, moves to Bolivia, finds God, or croaks. $1K for a sprit when I don't know for sure that I'll even be going the assy route is beyond my means. If I decide to go this way, then a "scratched" Trogear sprit might be justifiable! It's not that I don't like the product, I've stared at your web page at length, drooling!

As for rating, this just goes to show how differently folks think. I don't pay much attention to ratings, though I probably should.

Lets say the committee penalizes me 3 sec a mile for having a sprit and an assy. A typical SSS in the bay race is about 20 miles, point to point. 20 miles X 3 seconds is 60 seconds. On one hand, If I 'm slow with one spinnaker set or douse, I'll lose a lot more than one minute. One single goofed-up decision about "which way to go" will cost me immensely more than one minute. I can easily botch a tack, singlehanded with a big headsail up that will cost me half a minute. In the overall scheme of things in our kind of racing, one minute is pretty irrelevant.

On the other hand, another way to look at it is like this....

One nautical mile is 6,080 feet. That means in one hour, a boat going one knot covers 6,080 feet. A boat averaging 5 knots goes, close enough, 30,400 feet in an hour. Do the math; One minute at 5 knots is 508 feet, or a football field and 2/3rds. If you're averaging 6 knots, it's two football fields. That's a lot.

Another way to look at it is like this.....how many top-five division finishes in the SSS season would have been changed by a one-minute change in finish time?

OK, I don't have time to go look at every single 2016 SSS race, so I just looked at Saturday Vallejo 1-2 results and the Round the Rocks results. I was surprised.

Vallejo 1-2 Saturday

DH non-spinnaker... 1st-2nd ... 4 sec
DH non spinnaker .. 3rd-4th ... 40 sec
SH spin <108... 2nd-3rd ... 51 sec
DH Spin <108 ... 2nd-3rd ... 41 sec
DH Sportboat... 2nd-3rd... 43 sec

Round the Rocks

SH spin 111-159...2nd-3rd... 52 sec (two Wyliecats, different ratings)
DH Spin 111-159...3rd -4th ... 11 sec
DH Sportboat ... 4th-5th... 17 sec
DH Exp27 ... 2nd-3rd... 50 sec

In light of that, a 60 second rating change over a 20 mile race is definitely something that can change your placing in a race once or twice a season.

 

[Henry D]

Hey Alan, thanks for the complimentsand for a fellow singlehander, I am happy to make it work for you. Contact me.