PDA

View Full Version : Wind Range Chart


nicolo.piccolomini
14th May 2011, 02:57 PM
Hi
i use north sails and since they do not have a forum (btw if anyone has any relationsip with north could you tell them to put one up?) then i am going to ask my question here: do the wind range charts on the neilpryde sites apply for all types of sails (e.g. would the chart for a neilpryde atlas be the same for the north ice and the neilpryde hellcat (6.2) be equivalent to the north natural (6.2 (from 6.2 up the natural is performance oriented))?
thank you

joe_windsurfer
14th May 2011, 05:09 PM
Wind charts are more difficult to do than people realize. The last time i reviewed and discussed the numbers on the NP website, the numbers did NOT make ANY sense. There are just TOO many factors. Yes, your weight is one. The board is obviously another. The list goes on and on. You could probably predict the range based on your own experiences... and then adjust for cambers, etc.

Experts use sails in winds where someone else would be down 2 square meters in sail size !!! Antoine Albeau uses an 8.5 in winds as high as 20 knots/35 kph. In these winds i would tend to be looking at a 7.0. and i weigh more than Antoine

in summary - one cannot put exact solid wind ranges against a sail. They are all reasonable guestimates (except the ones on NP which seemed unreasonable :-)

good winds and good luck with this
i have some discussion on this in the sail section of my blog - http://joewindsurfer.com

btw Fanatic have a forum at www.fanatic.com and most of them use north sails - post there ??

nakaniko
15th May 2011, 06:27 AM
http://img1.fotoalbum.virgilio.it/v/www1-1/649/64903/105409/velaperfetta-vi.jpg
from Surf, Germany
not perfect but could help

joe_windsurfer
15th May 2011, 06:26 PM
nice chart {put a copy of it on my blog} - am surprised at suggestion of 6.5 down from 8.5
when i extrapolate for my 97 kilos, i would use a 7.5 in 16 to 20 knots - i use 8.5
just for fun - here is my windchart - created from my numbers, james douglass' sail calculator and redsurfbus blog numbers

http://3.bp.blogspot.com/-JaglS1vlP00/TZZdLRPU0pI/AAAAAAAAAIU/R--t51jN5_s/s1600/windvsbeaufart.JPG

http://joewindsurfer.com

btw fanatic forum did not answer yet - sometimes need 2 b patient with them ...

nakaniko
18th May 2011, 10:54 PM
Imho it's clear that there are many factors that can change the choice of sail size.
Yesterday I was on "my" little S. Croce Lake with gusty wind from 15 to 20 knots and my camless 7 battens 6,5 sqm was perfect for my 90 kg with my Score 112 allowing me to plane all the time when wind was blowing; obviously suffering wind holes much more than slalom riders. Cambered sails can handle more wind, so you correctly use sized up sails, freeride camless ar pheraphs more planing ready but cannot handle much more wind, f.e. with my camless 6,5 at 20 ktn I have to give up and rig a smaller size.
In fact yesterday freestylers were with 5,8, slalom riders with up to 8 sq and more.
My simple chart for riding outside Venice is: below 10 ktn 9,5 and big board, upt to 15 ktn (average) 8 sqm, over 15 upt to 20 6,5, from 20 or slightly less to 25 ktn 5,5 or 5,3, around 25 ktn 4,5, then over 30 and more I should put 3,7 but before call the hospital to prepare a surgery for my back spine c6-c7....
In Vencie all things changed from day day the Serenity arrived, now I enjoy a lot in 5-10 ktn with a simple old camless 8,5, I'll try the 9,5 just to have a lower planing threshold jumping over the Fanatic Sting Ray 150 (138 lt) TT, but I think Serenity doesn't really need 1 sqm more, as told by Roger.

Unregistered
19th May 2011, 05:27 AM
Its been my experience that windier it gets the closer the sail choice becomes for different weight sailors.
I also think the physics involved backs this observation aswell. Its somewhat ituitive if sail differences are thought of in percentage differences. A constant sail difference (as suggested in first chart) is sheer rubbish abd makes sail choice harder and not easier; making it harder for those with less experience to make sail choices.

I`ve been sailing with same few mates for 30 years. In light winds I need 1,5 metres more to planew up anything like as early. In 30 mph might be as little as 0.3 metres difference.

Charts are more trouble than they are worth. Only way is by gaining experience in sailing overpowered sometimes;underpowered sometimes and eventually been able to make correct decision to arrive at level of comfort/speed/handling required. A chart for different weights can simply never do that even before board choice/fin choice is introduced.

I can feel totally overpowered; change to smaller board /fin and it can feel totally comfortable.

Farlo
20th May 2011, 09:36 PM
Hi all, I've found James Douglass calculator pretty useful so far, but I don't get the same figures at all. Slightly above 65 kg, I would be dying in F4 with 6.2 m. This rather matches the upper limit (16 knots) than the lower (11 knots). This been said, I rig with lots of downhaul. And in 30 knots I may use less than 4.5 m for sure, but 3.0 as per the German chart seems very conservative. BTW isn't this chart made for wave sails?

nakaniko
21st May 2011, 04:21 AM
If you are talking about the german one, I don't know. Someone suggested and gave me this chart years ago, right in this forum if I well remember, and as for me it seems to work almost good, it became my standard.

Farlo
22nd May 2011, 07:46 PM
Stupid question, sorry. There are of course no 8.5 wave sails. If this chart dates from the 90's then it would make sense also for light weight. My biggest sail was NS Prisma 6.3 at this time. Nowadays I use 7.8 in not much lower wind