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-   -   Board Design or Physics ? (http://www.star-board-windsurfing.com/forum/showthread.php?t=5529)

Unregistered 27th March 2009 04:30 AM

Board Design or Physics ?
 
Was watching a good freestyle sailor;he weighed around 65k (guess) was on a modern freestyle board (90 litres/60cm wide) and using a Combat 4.2.
His acceleration out of blocks was incredible;his abilty to stay on plane amazing;uwind ability great and control in chop looked pretty good too.
Now I reckon theres no way any 90K + sailor could replicate this mix.(on any board/rig combo) Fair enough heavier sailors might well overhaul him on longish runs but short runs no chance; and his speed onto plane was almost instant.
Is this down to simple (???) physics(power to weight etc) or lack of board choice for heavier saiors.? (Biggest freestyle 108 ish ?)

crazychemical 27th March 2009 03:19 PM

it's probably a combo ... For planning you need a certain planning surface, the more surface, the earlier you plane (width of the board vs it's lenth and rocker). Also there's the factor on how much of your weight is pulled forward by the sail, so sailsize vs windspeed vs body weight. So in this logic, you should be able to get the same effect in planning with an identical board as the 60 K sailor but then with a 1.5 times bigger board, which makes the board too wide to freestyle anymore and with a 1.5 times bigger sail, which is doable but on a 90 cm wide board you need a bigger fin which again gives problems on the sailrange. So all in all, the problem is simple but has no effective solution, us heavy guys will always be screwed on light wind days and in certain surf diciplines. Thats why we've started to love our belly's more and more and with a beer in our right hand cruise the slalomtrack showing those lightwind boys what we do best.

Farlo 27th March 2009 04:31 PM

Well said. Look at girls: they plane in almost no wind with amazingly small boards and sails. Weight is the secret...

Unregistered 27th March 2009 04:48 PM

Physics then
 
So its physics then ???

I`m 95 k and couldn`t come up with a combo that I could have competed with. (I`d have ben overpowered on anything over 5, but perhaps I`m a wimp)
I think over 200 metres plus I`d have reeled him in but it was quite remarkable his speed over first 50 metres. (and his direction;ie well into wind and with a tiny fin !!)
Was impressive !

Made me want a freestyle board for B+F !

crazychemical 28th March 2009 07:16 AM

i have the same. i sail a freeride board which is 59 wide, and my buddy sails a 62 cm freestyle board. He has 10 L less in volume and he weighs less then me (like 35 K of difference). when i'm sailing 6.2 this guy is usually on 5.5 or 4.2 depending on how overpowered I am and still i have to be seriously overpowered to catch up with him within our 100 m run (we don't have a very wide sail area with SW, on NE we get a 400 m run and i kick his ass only after 300 m). So weight, board width, all factors. and the earlier you plane, the faster you get to your topspeed, but the wider your board, the lower that speed is (usually). You can cath up with this guy after 200 m only because he starts to get controle issues because of his weight when you only start to feel comfortable and want to accelerate.

carvesalot 29th March 2009 06:04 AM

just as a matter of curiosity. Would a freestyle board of similar volume to a allrounder
( the Fstyle is probably going to be 2cm wider)

so would it handle chop, swell as well ? a more precise example would be the Kode 102 @ 65cm and the Flare 106 @ 65

to me the Flare would plane sooner , but the Kode could handle un stable sea states more better..... well yea I did go to skool it just came out thata way

serious question .. anyone ?

Unregistered 2nd April 2009 09:40 PM

Noticed the exact same thing sailing with a light freestyler on a 2008 90 Flare and 5.0 sail with RDM mast... 23 cm fin. Crazy efficiency in 15 knots, air temp 15 c, planing away, doing flakas when others on bigger stuff were gust hunting. Light sailor weight seems to help but so does light gear weight, he had carbon everything.
As do the width discussion, width and a larger fin lowers the planing threshold. Judging from the Flare's performance, board width makes a bigger differance than fin size. A narrow board requires higher speed to plane, but displaces water better than a wide board, so it "slogs" faster. A (light) guy on a 120 l freeride board might need only a 6.5 to plane in 12 knots, The same guy on a 150 GO might need a 7.5 or larger to plane in the same conditions, but the board will lift off at a slower speed ("earlier') and continue to plane at a lower velocity. A wider board requires a more powerful sail/larger sail for the same wind speed but rewards with much greater planing efficiency than the narrower board with a smaller sail.

Screamer 6th April 2009 01:38 AM

Quote:

Originally Posted by Unregistered (Post 30712)
lack of board choice for heavier saiors.? (Biggest freestyle 108 ish ?)

On the other end there is also a lack of choice for ultralight sailors (say < 60kg) who want to sail in, say, 40 knots (I guess they'd need 50l waveboard). Not enough demand for mass production.

So if you're 100kg you simply cannot perform freestyle to today's standards. Pick another discipline. I haven't heard about heavyweights complaining that they can't win gymnastic competitions ;-)

HotIce 8th April 2009 12:55 AM

Fat
 
Combination of power to weight ratio, skill, equipment and how it is set up..

For example early planing / acceleration.........

The fastest sprinters in the world out of the blocks over 100m are no light weights. They are athletes with superb power to weight ratio whereas most windsurfers over 90 kgs are simply fat.

Early planing is a key skill and too many people use their weight as an excuse to cover poor planing skills.

Screamer 8th April 2009 07:18 AM

Quote:

Originally Posted by HotIce (Post 30995)
whereas most windsurfers over 90 kgs are simply fat.

Now get ready to take some flak from heavyweight forumities ;-)


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