Wednesday, February 01, 2006

What is the Difference?

Checking further into the San Diego and Newport issue and came across some great excerpts and advice from the J/24 US class website forums.

Brad Read had some insight into where it all started:

The Newport and San Diego designed J/24 Sails are design evolutions that have come from Vince Brun and Ken Read's sail lofts over the last 15 years. The sails are designed using the experiences that the J/24 sailors have had over these years.

He goes on to say

Basically, the designs reflect rig tuning philosophies more than any difference in sailing conditions where the 2 lofts are located.

San Diego North Mainsails are fuller and have more curvature in the bottom 1/3rd of the luff (luff curve) of the sail because the NS SD tuning philosophy historically has relied on more Pre-Bend in the mast. This flexibility is a plus for inducing headstay sag in light air, among other reasons. The San Diego Main required a genoa to match and the San Diego GP Genoa reflects shape features to match up with a
fuller mainsail.

The Newport Mainsail was also developed with a specific tuning theory in mind. The Newport Mainsails are constructed with less luff curve (for a straighter mast ). The area taken away from the luff curve gets put onto the lower roach to increase power in the back of the sailplan. (reducing the ever-present leeward helm problem in light air.)

The straight mast allows for greater headstay tension in heavier air. The backstay load is translated into more headstay tension in breezes where de-powering is needed.

Clears that up. Now as to which is better Geoff Moore, Owner of the Newport Shore Sails loft offers this bit of advice on choosing one over the other:

last year at the midwinters all top five boats had different sail designs. This year at Key West five of the top six had different designs. There was no discernible pattern to the order. I am sure there are plenty more examples, but the point is that the J/24 One Design rule works! In every regatta there are times when we are fast and then times when we struggle. There are just too many variables to explain exactly why this happens.

My next task is to find out how to identify which sails I inherited with the boat. Hopefully there are markings on the main, genoa and jib that will give me some indication. The logic online seems to point to having the same design for all sails based on rig tuning.


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