myiW Current Conditions and Forecasts Community Forums Windsurfing Videos Buy and Sell Services
 
Hi guest · myAccount · Log in
 SearchSearch   ProfileProfile   Log in to check your private messagesLog in to check your private messages   RegisterRegister 
luff vs boom length
Goto page Previous  1, 2, 3, 4, 5, 6, 7  Next
 
Post new topic   Reply to topic    iWindsurf Community Forum Index -> Windsurfing Discussion
View previous topic :: View next topic  
Author Message
isobars



Joined: 12 Dec 1999
Posts: 13288

PostPosted: Sat Sep 29, 2012 9:09 am    Post subject: Reply with quote

U2U2U2 wrote:
3 others have said what I did, Konajoe, Adywind and techno900 , 3 said longer boom

No, they did not. Adywind and Techno dispute your claim, Konajoe dodged the chord length issue altogether, tall & long = bigger sail, and I'll bet you a board that Bill Hansen, Steve Gottlieb, Bruce Peterson, Blake Richards, Monty Spindler, Dave Ezzy, et.al, would refute your answer, probably unanimiously. Of the many sail designers, pro and expert sailors, and WSing mag technical editors and test directors I've talked with and/or interviewed for consumer and trade windsurfing magazine articles, you are the first person I've ever heard to claim that higher aspect ratio sails plane earlier (have greater low-wind power).

I'm not qualified to declare the correct answer, but those polls answer the OP's question 99% in favor of longer booms.
Back to top
View user's profile Send private message
U2U2U2



Joined: 06 Jul 2001
Posts: 2976
Location: Shipsterns Bluff, Tasmania. Colorado

PostPosted: Sat Sep 29, 2012 10:40 am    Post subject: Reply with quote

I haven't claimed anything

I prefer shorter boom VS longer boom , being the answer in context with the question

I answered the original question.

_________________
K4 fins
4Boards....May the fours be with you

http://www.k4fins.com/fins.html
http://4boards.co.uk/
Back to top
View user's profile Send private message
isobars



Joined: 12 Dec 1999
Posts: 13288

PostPosted: Sat Sep 29, 2012 10:44 am    Post subject: Reply with quote

You can't fool us. You're outed ... Barack.
Back to top
View user's profile Send private message
swchandler



Joined: 08 Nov 1993
Posts: 5450

PostPosted: Sat Sep 29, 2012 1:37 pm    Post subject: Reply with quote

I have to admit that U2U2U2 did answer DelmarEdwards' original question. While not everyone agrees what they like the best, I believe that we are all subject to the designs and styles being promoted at any given time. It's the same thing with board designs. Look at the latest trend with short luff 4 batten sails for wave sailing. 5 years ago finding a 4 batten sail would have been search for something that didn't exist. Of course, you go back far enough in time, 4 batten sails were once very popular.

Another trend over the past few years has been cut-out clews to reduce swing weight, while still maintaining a fuller roach to sustain power above the boom. Going back a little further, sail designers were playing around with luff curves. Now, there are some designers that are going back to straighter luff curves that are not as dependent on so much downhaul pressure. In my view, it's a welcome change given the fact that a deep luff curve can make rigging a pain in the ass.
Back to top
View user's profile Send private message
jingebritsen



Joined: 21 Aug 2002
Posts: 2293

PostPosted: Sat Sep 29, 2012 2:57 pm    Post subject: Reply with quote

yes, 4 batten wave sails might as good as they were years ago, in a steady state wind venue. also, like before, i doubt they will be that great in gusty places. especially now we are prone to using skinny masts. the trade winds folks have lots of luxuries that others don't. i wonder why we keep getting sold trend after trend that only seem to work in warm windy spots that end up adding to the frustrations for the rest of us when we are gullible enough to try the latest and greatest(?) stuff... i've tried the koolaid all too often, it just ain't it's all cracked up to be.
_________________
www.aerotechsails.com
www.exocet-original.com
www.iwindsurf.com
http://www.epicgearusa.com/
http://powerexmasts.com/?page_id=72
Back to top
View user's profile Send private message
DanWeiss



Joined: 24 Jun 2008
Posts: 1889
Location: Connecticut, USA

PostPosted: Sat Sep 29, 2012 9:35 pm    Post subject: Reply with quote

adywind wrote:
Before you dump your money for a "half" cambered sail please read this article: http://www.point-7.com/downloads/tests/Boards-June2011.pdf
It absolutely reflects my own dissapointing experience with 2 and 3 cambered sails from different brands. Long story short ,I'm replacing my quiver with RAFs and so far I'm very happy . I plane earlier , jibe smoother, go faster and when I start getting overpowered, I just switch to a smaller rig and board instead of playng a hero like before beeing on a 2 sizes bigger sail then everybody else and destroying my limbs in the process.
If you race -go for the real race ones, if not -choose the light, fun stuff...is my new philosophy Smile


No debate, but the main photo of the two sails side-by-side says a great deal about tuning. The RAF sail was missing large amounts of batten tension and that can make a sail perform far differently than when adjusted using DH and OH only. Without the tension, the sail will pump very nicely in lighter winds. Did that test then add tension in higher winds to return stability to the sail? Without knowing that, it's hard to take the conclusions in that article seriously. This isn't saying they're wrong, just that it's very suspect if they screwed up the batten tuning without realizing it before the photo session.

_________________
Support Your Sport. Join US Windsurfing!
617.259.0411
www.USWindsurfing.org

www.konaone.com
Back to top
View user's profile Send private message
DanWeiss



Joined: 24 Jun 2008
Posts: 1889
Location: Connecticut, USA

PostPosted: Sat Sep 29, 2012 9:46 pm    Post subject: Reply with quote

I'm not trying to be the authority on anything here, but it is basic, black letter science that high aspect foils are more efficient than lower aspect foils of the same thickness ratio. There is a reason we now sail very high aspect fins in most applications today compared to 25 years ago. They work.

Yet, as many point out, you can lengthen the mast and increase the aspect ratio only to the natural limit of the human body to control the pitching moment. We can't grow taller or extend our arms and legs, and those sails on long masts can become very tough to control in large chop. We experimented with aspect ratios in the mid to late '80s and it became clear that sail design wasn't all science but had to comport to the human who used the sail as well as the masts.

Todays masts far exceed what was offered even ten years ago. They are more consistent, generally higher in high modulus carbon content and are lighter weight in their top half. This allows sails to come around with reduced luff lengths while still maintaining great handling.

_________________
Support Your Sport. Join US Windsurfing!
617.259.0411
www.USWindsurfing.org

www.konaone.com
Back to top
View user's profile Send private message
konajoe



Joined: 28 Feb 2010
Posts: 99

PostPosted: Sat Sep 29, 2012 10:43 pm    Post subject: Reply with quote

But, back to the original question, I hope you're not thinking of buying a sail based only on ability to plane early. Like Dan is saying, basic science says that the high aspect sail is more efficient, but you may not be happy sailing on such a sail over a wide range of wind conditions. Old Mistral One Design sails were real powerful for their size, but that high aspect ratio is tough to handle overpowered.

Also, earliest planing is achieved by pumping. I'm thinking I could pump onto a plane better with an old high aspect sail. Didn't windsurf magazine do an article years ago about newer sails having less 'grunt' meter per meter?

We should figure out how to do Windsurfing Mythbusters.
Back to top
View user's profile Send private message
U2U2U2



Joined: 06 Jul 2001
Posts: 2976
Location: Shipsterns Bluff, Tasmania. Colorado

PostPosted: Sat Sep 29, 2012 11:25 pm    Post subject: Reply with quote

It depends on how long and short the luff and boom are.


A longer boom "evens" out the wind so it carries through the lulls better.



A longer luff is usually associated with a bit less leech roach, which is better in lighter wind.


So, the best would be a longer luff and a longer boom.


If the luff is not too short, a longer boom is always the best for light air.



David Ezzys take on the question.

_________________
K4 fins
4Boards....May the fours be with you

http://www.k4fins.com/fins.html
http://4boards.co.uk/
Back to top
View user's profile Send private message
beaglebuddy



Joined: 10 Feb 2012
Posts: 502

PostPosted: Sun Sep 30, 2012 12:25 am    Post subject: Reply with quote

http://forums.boards.mpora.com/showthread.php/36218-That-Hi-Aspect-Sail-of-Mine


sail15.jpg
 Description:
 Filesize:  56.88 KB
 Viewed:  1221 Time(s)

sail15.jpg


Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    iWindsurf Community Forum Index -> Windsurfing Discussion All times are GMT - 5 Hours
Goto page Previous  1, 2, 3, 4, 5, 6, 7  Next
Page 4 of 7

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum

myiW | Weather | Community | Membership | Support | Log in
like us on facebook
© Copyright 1999-2007 WeatherFlow, Inc Contact Us Ad Marketplace

Powered by phpBB © 2001, 2005 phpBB Group