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PostPosted: Wed Jul 11, 2012 11:39 pm
by evanwellens
Help!!! We race PHRF and recently had to replace the furler/forestay due to an accident last season. Seems nothing we can do will get the boat to point. We'll have great starts and then our position just slips away. Desperate for advice as this is ruining our season.

PostPosted: Thu Jul 12, 2012 7:52 am
by raywulff
A question to work on a diagnosis.

Are you sailing with a 150% or 100% jib?
With the headstay being replaced, it is a different length?
Do you notice the jib clew height higher than what you remember last year?

PostPosted: Thu Jul 12, 2012 9:57 am
by evanwellens
We sail with a 135%. We did measure the headstay to spec. Wondering if it stretched. The clew appears to be in the same spot, that said if it were off by a nominal bit I'd probably be able to differentiate.

PostPosted: Thu Jul 12, 2012 4:50 pm
by Guest
Try measuring from the black band on top of mast to the edge of the stern cutout. It should measure 37'4 1/2". If the fore stay stretched even a small amount it can have a much larger effect on the overall rake. We replaced our furler recently and it did stretch a small amount.

[Posted by: randy
]

PostPosted: Thu Jul 12, 2012 5:52 pm
by kcpilotpat
How do you measure that distance? attached a slug to a tape measure and pull it up with a halyard?

Assume this is with the backstay off? Shroud tension and mast butt placement is going to have a lot to do with that dimension.

I like the concept of this dimension because it takes a lot of variables and gives one dimension to measure to if everything is set right.

Pat

PostPosted: Thu Jul 12, 2012 6:06 pm
by aburton
Check the Quantum web site; the whole method is explained in excellent detail in the J/80 part.

PostPosted: Thu Jul 12, 2012 11:13 pm
by kcpilotpat
Took a little effort to find it on the quantum web site.

http://www.quantumsails.com/kbase/summa ... d6de037053

PostPosted: Fri Jul 13, 2012 10:51 am
by evanwellens
Thanks everyone !!! Will try to work on it sunday and report back.

PostPosted: Sun Jul 15, 2012 7:22 pm
by evanwellens
So we did the kerry test and the measurement was 3 inches off. Didn't have time to fix it since massive storms came in. Others have suggested working the halyard tension to increase pointing ability. Anyone have any expierience with this ? Supposedly the jib with light scallops is better than over tensioned.

PostPosted: Mon Jul 23, 2012 10:16 am
by evanwellens
So we had some friends out who are extremely competitive sailors(non j80) in our area for a peek at the rig. The opinion was we are raked too far back ( in agreement with the measurement ) but also that our forestay had no sag ( I kind of thought it a bit loose). So that leaves a quandry , shorted the forstay or adjust the mast butt ? Attached it a pict that compares our rake w/ a j29 and 27. <img src="http://j80.org/discus/messages/4/1130.jpg" alt="Mast rake profile"> , we are the red sail cover

PostPosted: Mon Jul 23, 2012 7:54 pm
by Guest
I would start with forestay, I think the idea is to get the rake correct then you move the butt around to change the pre bend in the mast. Call your local sail loft to be sure.

[Posted by: Randy
]

PostPosted: Mon Jul 23, 2012 8:40 pm
by evanwellens
Thanks for replying !!! Interesting. We maxed out the forestay length according to class rules when we set it up. I forget the reason , but supposedly longer was better. Our measurement according to the kerry video is 3 1/2 inches too short. Concerned I'd have to extremely shorted the forestay to correct that , and we might have too much forestay tension. IMHO the pre-bend looks ok, but I'm no expert. What's more odd , the pointing has degraded since may. Thought the forestay might have stretched but someone told me that heavy wire doesn't stretch. Guess I'll have to de-tune and take the furler apart , perhaps reduce the length by 1 inch, and see where that leaves us. After that perhaps the mast but position ?

PostPosted: Tue Aug 14, 2012 8:26 pm
by prexelius
I get a bit confused here; thought that more rake would give you more weather helm and that would help pointing higher. I'm new on the J80 since last year. But I would try to move the mast butt aft a fraction of an inch and see if that does not help. That should give you more sag and increase the distance mast top to stern. I assume you have to slack all the shrouds when doing it.