Ok so second time playing with my new asymmetric today. Even had the wife on board and she put it up and put it down once. Pretty light breezes never saw much more than 11 knots and for brief periods it was only a couple of knots.
Haven't played with spinnakers for a long time but I'm thinking they need to exhaust just like a normal sail particularly when they are shy and I'm wondering whether I should take this sail back and get the luff tape relieved or if that is even a possibility. Actually the foot does the same thing.
Maybe I could have taken better photographs but I attach one photograph together with a zoom in on the Leech and the foot using the same picture.
I would really appreciate some guidance here. Thanks in advance.
Any sail with a positive roach will hook a fair bit in the absence of battens. Ease the tape or straighten the shape and it will flutter like crazy. Hell, even some hollow leech sails like genoas or battenless mains have leech hook particularly if very flat on trailing edge. As the late great Ben Lexcen said to me as a young sailmaker when looking at an America's Cup Genoa
" we could spend all night fiddling with that and difference in boat speed = 0. Wind flows across a sail like a tumbleweed, not like a knife through water"
For my two bobs worth 
Need to know true wind angle at the time you took the photos. If the wind is asternish hooking probably not that bad, but if you are trying to reach it might slow you down. You want the breeze to flow smoothly off the leech. The hook stops that. But as Galatea said its not going to make much difference unless you are in a match race.
Select to expand quoteTrek said..
For my two bobs worth Need to know true wind angle at the time you took the photos. If the wind is asternish hooking probably not that bad, but if you are trying to reach it might slow you down. You want the breeze to flow smoothly off the leech. The hook stops that. But as Galatea said its not going to make much difference unless you are in a match race.
Reaching as high as I could go.
I find it hard to believe that this is desirable. I wonder if it is a matter of relieving the tape or whether the entire cut is incorrect?
Its possible the sail has stretched. Or maybe the original cut was for more downwind performance. Im not knowledgeable about that. At one time I had a light weight Genoa that hooked. I took photos of it and took at to a sail maker who cut vertical strips out of it near the centre and that improved it a lot.
Will obviously open out more when sheet is eased. Look at picture you posted earlier. The two spinnakers on left are Assys I think but regardless show the difference.
One is eased a bit, clew raises - leech opens. The other sheeted on with clew lower and leech curls.
It is not a biggie, if you wanted a high sailing reaching sail, then the cut is wrong, it would be a Code 0. If you want an all purpose sail then there are compromises! It is not desirable but not that big a problem.
It will get even rounder and more pronounced as the sail ages, the base cloth stretchs and the tapes shrink a bit. on racing boats we do ease the tapes after a few years. 
These are questions you should be asking the sailmaker. What did you ask for. What wind angles and strength did you want to cover.
You are pointing pretty high by the looks of it as the breeze is light. Get a bit more pressure in the sail or come down a bit and it will go away. I think as someone already said if it's too loose and flutters it's a lot worse. So if there is no hook when sheeted in tight there will be flutter as pressure builds and you come down. Making A'sails that cover a large wind angles and strengths is not easy. Like everything in sailing there is a compromise and a hooked leech in light airs is better than fluttering in more pressure.
But ask the sailmaker.
Yeah it the sail. The doubled over tabbing doesn't stretch at all, I got told that it even shrinks. So in my dighy days I used to get the kite luff tapes lengthened by the sailmaker. You run up them with the unstitcher and then stitch them back on with a little extra tape.
Thanks for all the answers and ideas.
I didn't realise that there were tiny thin little leech and foot lines. I backed these right off today but there was too much wind to try the sail. It's 0.9 oz and I only really want it for light breezes so I didn't want to risk stretching it or blowing it out today. The boat was hitting 8.7 knots in the gusts coming home in the flat water back down Pittwater with only my relatively high cut 108 percent jib/genoa. Not expecting that the lines were the problem though.
Select to expand quotejulesmoto said..
Thanks for all the answers and ideas.
I didn't realise that there were tiny thin little leech and foot lines. I backed these right off today but there was too much wind to try the sail. It's 0.9 oz and I only really want it for light breezes so I didn't want to risk stretching it or blowing it out today. The boat was hitting 8.7 knots in the gusts coming home in the flat water back down Pittwater with only my relatively high cut 108 percent jib/genoa. Not expecting that the lines were the problem though.
If it is 0.9 oz on a Northshore 38, it is good for plenty of breeze.
The boat will fall over before it blows out.
Select to expand quotelydia said..julesmoto said..
Thanks for all the answers and ideas.
I didn't realise that there were tiny thin little leech and foot lines. I backed these right off today but there was too much wind to try the sail. It's 0.9 oz and I only really want it for light breezes so I didn't want to risk stretching it or blowing it out today. The boat was hitting 8.7 knots in the gusts coming home in the flat water back down Pittwater with only my relatively high cut 108 percent jib/genoa. Not expecting that the lines were the problem though.
If it is 0.9 oz on a Northshore 38, it is good for plenty of breeze.
The boat will fall over before it blows out.
Thanks. I kind of assumed that because Rolly Tasker only offer theirs in 1.5 oz for that size that 0.9 was a bit light. The boat already goes fast in medium to strong breezes so I only wanted it for light stuff and I didn't want it to collapse. Already had it up on a pretty light day so happy with weight. Good to know it's safe for a bit more though :-)
Attached a couple of pages from perf race trim on asyms. Interesting about easing different lines depending on your desired point of sail.
Select to expand quoteDrogueOne said..
Attached a couple of pages from perf race trim on asyms. Interesting about easing different lines depending on your desired point of sail.
Thanks :)
