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8th July 2010 11:49 PM
Farlo See what you mean. I have a Naish 6.6 hardly larger than an older North 6.0 but with much more grunt. Looking at them you would not say one has 10% more surface. The 6.6 is probably exaggerated to reflect the sail power, so that it fits nicely in the product range compared to other sails.
8th July 2010 10:16 PM
Floyd Hi Farlo
Yep;its why I started with the calculations.
I have 2 "5 metre" sails.
A Gun MC wave and a NP Combat. The Combat is lots better in strong winds; the Gun loads more bottom end.In theorey both 5 metres but on my scale the MC comes out around 75; the Comat around 70.(Similar aspect ratios too !!!) So obviuosly the Combat is better in strong winds ; its smaller !!! (Both 5 metre sails can go in same quiver !!!)

My biggest sail is 7.5 metre (107) but compares favourably with most 8 metre sails on my scale. My 7 (in theory only half a metre smaller) scores only 97; so it fits in my quiver.
Floyd
8th July 2010 08:20 PM
Farlo Hi Floyd, I've done similar statistics on my sails collection, basically calculating the ratio between claimed surface and inner triangle area. Overall I've found numbers around 1.4 with wave sails having (logically) a smaller ratio than freeride/race sails. But also it can vary sensibly from one brand to another, one model to another, and even one year to another. Sail surface seems to be affected by same marketing tricks than board volume.
8th July 2010 03:00 PM
Unregistered
Quote:
Originally Posted by Floyd View Post
Hi
Its a little off topic but a technique I use to compare my sails (from different manufacturers/ranges) is boom length x mast length (in cm) divide by 1000.

A 7 metre comes out around 100. A 5 metre around 70. Its sort of a power index which I find better for comparing sail "sizes" than quoted areas.

See where yours comes out and then work backwards to size.



580*210 /1000 = 121.8
500*244/1000 = 121.8


475*210/1000 = 99.75
445*224/1000 = 99.75


nah forget it stick with area......
8th July 2010 04:01 AM
Floyd Hi
Its a little off topic but a technique I use to compare my sails (from different manufacturers/ranges) is boom length x mast length (in cm) divide by 1000.

A 7 metre comes out around 100. A 5 metre around 70. Its sort of a power index which I find better for comparing sail "sizes" than quoted areas.

See where yours comes out and then work backwards to size.
8th July 2010 03:23 AM
Unregistered Good Lord Sir !
By the sound of your sail, it is more likely you will be paying somebody to take it away !
I recently saw some wallets in Tarifa made from "old sail cloth".
You might do better to "recycle" it some other way.........
7th July 2010 10:55 PM
nonopr There is an Application on iTunes that gives you the sail size depending on your weight and wind velocity.
The name is Sail Size.. Check it out. They also offer a windows excel program with the same things.
http://www.vims.edu/general/sailpadd...calculator.xls
http://www.vims.edu/general/sailpadd...calculator.xls
7th July 2010 10:25 PM
Cmarois Joe and Ken, thank you very much.

The sail is pretty much how you describe it, Ken: no laminate, small plastic window, no marking or number, and it's a grommet at the bottom.

Joe, I was dividing by 2, so your 1.5 is probably what I had wrong.

With a visual comparison (from memory) with the 4.5 sail, 5.5 or 6M would make sense.

I'll go with that.

Thanks for all the help, guys!

Chris.
7th July 2010 08:47 PM
Ken Sounds like a 25 year old regatta sail. Short mast and long boom with three short battens. Is the sail all Dacron (no plastic laminate on the sail), with a thick flexible window?

Given the mast and boom sizes, it my be around 5 - 5.5 meters. I still have my 1985 Superlight regatta sail and use it on the original board.

Are there any markings on the main body of the sail (numbers or a design)?

Any pulleys or just a grommet at the foot of the sail?
7th July 2010 06:32 AM
joe_windsurfer did an experiment since i have my sail specs in a spreadsheet

did reverse engineering and discovered luff * boom / 1.5 is REALLY close to sail size

so, in this case ...

4.11*2.13/1.5=5.836 sq meters
rounded up that's a 6.0 sail - make sense ??
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