18SX diamond wire tension/ "Wind Raider" can you help?

Since I have destroyed my Tiger ST main I am replacing it with a squaretop SX sail from Chip @ Whirlwind. I know several of you guys are running this sail and need to know about diamond wires in relation to the SX sail area and squaretop. I understand the diamonds on a standard H18 but there is no performance manual on the SX. I currently have the wires very tight to induce pre-bend which the Tiger sail needed. I don't think the new sail will need pre-bend at all but am quite unsure about the diamond settings.

How about "Wind Raider", I understand you guys are tearing it up on the left coast. How is yours set up?

I would ask the sail designer. They are the only one that knows how the sail is cut.

J

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Sail Revolution
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ncmbm,

I don't do a whole lot of racing other than two or three long distance races out of Ventura every year so I pretty much have set my diamond wires to where they touch the mast about a foot up the mast. This is on a standard 18 mast though. Still waiting on the spin to be cut. Jeremy was invaluable as far as helping me install all the needed hardware with minimum holes drilled in the boat I might add! He had all the needed parts when I arrived at his shop after a 4 hour drive to get there. We did end up using the bale setup on the halyard block as you did on yours, worked out fantastic! Sorry to hear your boat took some damage this past weekend. If you're anything like me though, you enjoy working on your boat almost as much as you do sailing it!

Tom

I do really enjoy playing with it. Wish I had more physics knowledge and could fully understand how one thing effects another on the boat. I feel I really don't understand how the diamonds work on the different boats. The Tiger has tight wires to hold pre-bend in the mast and the H18 runs slack wires. Based on this observation it would seem the diamond wires have completely different purposes on the two boats. My new sail will be a more modern design than the SX sail and will have some curve in the luff so my instincts are to bend the mast to fit the curve of the new sail. This will leave my wires tight but I feel the comptip will spill off alot with the squaretop so maybe I don't want the mast to flex between the diamonds.

Trial and error will most likely be the way to go.

Mike,
I agree with Jeremy and find out from the sailmaker the kind of cut built into the sail. That'll be your starting point for inducing any pre-bend into the mast.
Sounds like your tiger sail was cut round up front, compared to a stock H18 main which is cut nearly straight. Pre-bending the mast apparently gets the draft set properly at the beginning of tuning it.

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Chris
'88 H18SE Arís

I think hoisting the sail out off the track and then adjusting the wires to get the mast to match is the way to get initial set. I am confused as to whether the downhaul should be on hard and if the sail should be in the track below the feed. Unfortunately I will get the sail 2 days before the next race and will not have time to mess with tuning it much. The more I can get done ahead of time the better off I will be.