I think I want to raise the jib tack a bit higher so I can get the leech to close when I move the blocks forward in very light air. Right now we attach the jib tack to the plate at the bow of the boat with a long-ish shackle -- maybe 2". I guess that is legal: I don't know what the builder might've supplied for that. What am I allowed to do? May I get a 4" shackle? May I add a second shackle? Some arrangement of spectra? How far does "only builder supplied fittings" go?
Quote from: Thomas Leith on August 16, 2010, 05:55:50 PM
I think I want to raise the jib tack a bit higher so I can get the leech to close when I move the blocks forward in very light air. Right now we attach the jib tack to the plate at the bow of the boat with a long-ish shackle -- maybe 2". I guess that is legal: I don't know what the builder might've supplied for that. What am I allowed to do? May I get a 4" shackle? May I add a second shackle? Some arrangement of spectra? How far does "only builder supplied fittings" go?
You just need a small piece of line. Spectra isn't your best choice...ties poorly. Just get some maffi or marlow dinghy braid.
there aren't any rule implications involved with moving the tack of the jib higher. I dont quite see how raising the tack allows you to close the top of the jib more, when moving the jib cars forward will close the top of jib anyway. Unless your out of jib track I haven't seen a condition that requires the jib cars that far forward.
But anyway tying some line like a strop on the jib or just add more shackles, no biggie.
We have been using a higher tack position. Ronstan sells small spectra loops to use as soft attachments for their blocks. If you pass the loop through the cringle and hook the shackle on basket handle style, it works well. They are about $5 per loop which is pricey but it would be a tough task for a casual splicer to make these loops. This is definitely a case of paying for convenience.
The loop will gain you about 3/4" depending on how beefy you tack cringle is. You may get a little more if you go for a choker attachment but you severely reduce its breaking strength that way.
Thanks for the tips on line. We have a new Dieball jib and a week ago we pushed the jib cars all the way forward on the tracks to get the leech to close in ~4 kts or breeze. I really like the shape and I've always had a thing for deck-sweepers, but the sheets were two-blocked and I REALLY hate that. I want to see a little line in there so I thought I'd try a higher tack position. But there's this "strict one-design" thing. I'll come up with something. Thanks again.
No where in the rules does it mention how the jib must be tacked down.
Unless you interpret 1.6 or 1.7. I don't think these rules were intended to limit hot you attach the tack of the jib.
Once again the rules don't limit the height of the jib tack and another thing to consider is that in light air you want the jib twisting open along with your main to get the proper flow over the sails. Keeping your jib and main profiles to look the same will achieve your maximum speed in the light stuff.