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Old 24th March 2007, 09:21 PM   #4
Dream Team - School Guru
Join Date: Aug 2006
Posts: 2,177
Default RE: Sail sizes + power

Hi Floyd,
Ahhh... you've added another "dimension" to this discussion.
When you rig both sails on your "Amex 100 RDM" do they feel more
My experience with RDM's is that when you use them in a sail that was not specifically designed for an RDM, you get some odd results.
If a sail is designed for a std. dia. mast (vs RDM) the luff sleeve pulls nice and tight (since we are talking small size wave/B&J type sails here) on the SDM as that's the way it was designed.
Put the same sail on an RDM, and you get more draft depth further forward in the sail because there's some extra material in the luff sleeve because it was designed to fit an SDM with a larger circumference.
Also, RDM's and SDM's bend a little differently due to the RDM being more of a "straight tube" where the SDM is a "thin wall tapered tube".
So, some of the difference could be due to the mast diameter and bend characteristics, not just the design of the sail.
Also, in the example you use (NP Search vs NP Combat) it seems you are overlooking the "design intent".
Per the NP web pages:
Combat 5.0 417 luff 168 clew length on a 400 mast
Search 5.0 431 luff 166 clew length on a 430 mast
Per the Gun web pages:
'06 Wave MC 5.0 423 luff 175 clew length (Mast not specified)
So, as you can see from the specs., the NP Search has a signifcantly higher aspect ratio (luff length/boom length) than the Combat.
If we check the aspect ratio of your Gun Wave MC 5.0, it's got a much lower aspect ratio than either the Search or the Combat.
If you read the mfg. hype, the Search is the most powerful in the NP line and designed for heavier sailors that want/need/can handle more power.
The Combat is the "mid range sail" that was designed to "do it all" for all size/weight sailors.
The NP Zone is NP's rig for smaller sailors and ideal conditions.
If we look at the Gun MC wave, with the much lower aspect ratio and longer boom I think it's pretty easy to tell that this would be a more powerful sail, but less maneuver oriented and without the quick "depowering" that the Zone and Combat provide.
So, I think that asking for "standardization" here isn't ever going to work as there are alot more "features" and "mixes of features" to give each type of sail it's own unique "feel" and performance characteritics to suit a vast range of conditions and sailors.
I guess it's necessary to select your sails very carefully (after trying them in your conditions if possible) as simply going by the size, or your estimate of the power available in a particular size, does not result in any consistency.
Hope this helps,
Roger is offline   Reply With Quote