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#273896 - 07/14/14 10:49 AM Slow in light wind  
Joined: Mar 2008
Posts: 55
Mpls_Nacra Offline
journeyman
Mpls_Nacra  Offline
journeyman

Joined: Mar 2008
Posts: 55
Minneapolis
Hello, all I am relatively new to racing. I just got my Nacra F16. I find that when racing in light wind I am extremely slow. I keep thinking I am over sheeting and over pointing, but I am not so sure of that any more. I'd really appreciate some tips on how to improve boat speed. (I am sitting far forward, I allow the mast to rotate most of the way out) I am sure there is more I can do.

thanks for the advice.


Dave Foster
Minneapolis
Nacra F16
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#273906 - 07/14/14 07:07 PM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Jun 2001
Posts: 409
Mike Fahle Offline
addict
Mike Fahle  Offline
addict

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Toledo, Ohio (western end of ...
Are you using leech tell tales? The best way to know if you are over sheeting is to watch the tell tales on the leech (each one attached at the edge of the material). As long as they are flowing (indicating attached air to the leech) then you have not over sheeted. Once you do, the leech tells will cease flowing as the sail loses attached airflow and will swirl behind the sail or just droop. There should be at least two tell tales on the leech - one in the bottom third to indicate traveler trim and one in the top third to indicate mainsheet trim. Regarding trim in light air, follow the old saying, "When in doubt, let it out". Once the sail is eased and you sail a bit lower, gently trim in and adjust course accordingly until the leech gets too tight according to the tell tales and then ease back out a bit to get the flow going again. This applies downwind as well as upwind. In light air it is more likely that leech twist will need to be increased as there is likely to be more wind shear, especially the lumpier the water gets. More twist also gives the sail a wider groove but if the water is flat and the wind is pretty steady then sheet in as long as the leech tale is flying since a narrow grove is all you will need and you will be able to sail as high (or fast) as possible with the breeze you have.

#273907 - 07/14/14 07:16 PM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Apr 2004
Posts: 713
davefarmer Offline
old hand
davefarmer  Offline
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WA, ID, MT
Nice reply Mike, thanks!

#273908 - 07/14/14 07:16 PM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Apr 2004
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davefarmer Offline
old hand
davefarmer  Offline
old hand

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Posts: 713
WA, ID, MT
Nice reply Mike, thanks!

#273909 - 07/14/14 09:15 PM Re: Slow in light wind [Re: Mpls_Nacra]  

**DONOTDELETE**
Unregistered
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Don't let your rotation out upwind. Going upwind in light wind is all about efficiency. Read the first part of this this and set your mast so that it is working properly. Letting out the rotation is just adding drag. With a modern wing mast, rotation is the last place you should look (after cunningham and traveller etc) to changing power it should always be set so the luff tell tails are working. Once moving in really light wind your apparent wind will be a long way forward so if anything you need less rotation not more. Also don't be afraid to actively adjust this setting in the light. When you come out of a tack and have all but stopped the apparent wind will be at or above 45 degrees, as the boat accelerates it will swing forward to around 20-25 degrees so your mast setting will need to be changed to suit.

#273917 - 07/15/14 09:18 AM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Mar 2008
Posts: 55
Mpls_Nacra Offline
journeyman
Mpls_Nacra  Offline
journeyman

Joined: Mar 2008
Posts: 55
Minneapolis
Thanks for the info, I cant wait to try it out. I'll let you know.


Dave Foster
Minneapolis
Nacra F16
#273919 - 07/15/14 09:43 AM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Jul 2009
Posts: 19
US5352 Offline
stranger
US5352  Offline
stranger

Joined: Jul 2009
Posts: 19
Hi Dave. Best way to get faster is to race with faster people who will share all their "secrets." Come to the CRAW regatta in Green Bay in three weeks, and you'll learn a bunch and leave faster than when you came.

Best,

Daniel
Viper F16

#273938 - 07/15/14 09:11 PM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Feb 2005
Posts: 4,109
Karl_Brogger Offline
Carpal Tunnel
Karl_Brogger  Offline
Carpal Tunnel

Joined: Feb 2005
Posts: 4,109
Northfield Mn
Dave, if you want to come I'll even haul your boat for you.


I'm boatless.
#273952 - 07/16/14 09:31 AM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Mar 2008
Posts: 55
Mpls_Nacra Offline
journeyman
Mpls_Nacra  Offline
journeyman

Joined: Mar 2008
Posts: 55
Minneapolis
Karl, I am planning on going to broken rudder. possibly one other event.

are you coming out to MYC again any time soon?

Last edited by Mpls_Nacra; 07/16/14 09:31 AM.

Dave Foster
Minneapolis
Nacra F16
#273953 - 07/16/14 09:31 AM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Mar 2008
Posts: 55
Mpls_Nacra Offline
journeyman
Mpls_Nacra  Offline
journeyman

Joined: Mar 2008
Posts: 55
Minneapolis
Karl, I am planning on going to broken rudder. possibly one other event.

are you coming out to MYC again any time soon?


Dave Foster
Minneapolis
Nacra F16
#273955 - 07/16/14 09:46 AM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: May 2003
Posts: 4,451
Rolf_Nilsen Offline
Rolf_Nilsen  Offline


Carpal Tunnel

Joined: May 2003
Posts: 4,451
West coast of Norway
We also find that having quite some downhaul on in light winds is fast when being sucked upwinds. Usually there is not enough energy in the wind for it to stay attached over a Sail with a lot of draft. Flattening the sail removes the drag and perfomance loss of not utilizing all available energy in the wind.

I positively hate typing on a pad! And the norwegian spell checker does not help..

#273961 - 07/16/14 11:52 AM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Nov 2011
Posts: 370
rehmbo Offline
enthusiast
rehmbo  Offline
enthusiast

Joined: Nov 2011
Posts: 370
SE MI / NE IN
Read some place this mode (flat sail in light air) is akin to the aerodynamics of butterfly flight.


Jeff R

H18, C2 USA1193
cramsailing.com
crescentsail.com
#273970 - 07/16/14 09:22 PM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Feb 2005
Posts: 4,109
Karl_Brogger Offline
Carpal Tunnel
Karl_Brogger  Offline
Carpal Tunnel

Joined: Feb 2005
Posts: 4,109
Northfield Mn
It's usually so it opens the leech. Otherwise it's hooking severely at the top. You really aren't flattening it much because mast rotation will remain the same, and you aren't sheeting very hard.

I'll probably be up there at some point, no plans to store my boat up there this summer though


I'm boatless.
#273972 - 07/17/14 04:40 AM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: May 2003
Posts: 4,451
Rolf_Nilsen Offline
Rolf_Nilsen  Offline


Carpal Tunnel

Joined: May 2003
Posts: 4,451
West coast of Norway
A beachcat mainsail have about 10% draft when designed and built.
A rotating mast adds from 2-4% depending on mast.
Pulling on the downhaul will in my experience bend the mast and effectively flatten the sail.
After flattening with downhaul the leech can be sheeted in some more for additionally improved vmg.

A loose leech is the monohull way to reduce draft in low wind conditions ;-)

Try the different proposals and see what works for you.

#274014 - 07/18/14 10:33 AM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Mar 2008
Posts: 55
Mpls_Nacra Offline
journeyman
Mpls_Nacra  Offline
journeyman

Joined: Mar 2008
Posts: 55
Minneapolis
Thanks again everyone, What about diamond wires. where should the tension be light, medium and heavy wind. ( I am on the heaver side of the scale)

thx
DF


Dave Foster
Minneapolis
Nacra F16
#274016 - 07/18/14 02:47 PM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Feb 2005
Posts: 4,109
Karl_Brogger Offline
Carpal Tunnel
Karl_Brogger  Offline
Carpal Tunnel

Joined: Feb 2005
Posts: 4,109
Northfield Mn
I adjust the diamonds a lot of times between races. If I feel under powered I loosen them, if I was maxing out the downhaul a lot I'll add tension.

Last edited by Karl_Brogger; 07/18/14 02:47 PM.

I'm boatless.
#274041 - 07/20/14 02:32 AM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: May 2003
Posts: 4,451
Rolf_Nilsen Offline
Rolf_Nilsen  Offline


Carpal Tunnel

Joined: May 2003
Posts: 4,451
West coast of Norway
Why did sailors start experimenting with spreader rake and diamond wire tension..
They wished for a rig that was faster by automatically responding to small changes in windspeed. Depower in gusts and polering up in the lulls without the crew needing to do anything.
Spreader rake and diamond tension in the base form shapes the start setting for the mainsail. Draft and leech shape.



With a new Nacra i believe the supplied assembly manual specifies spreader rake and diamond tension to match the sails? I dont know the number but surely they are available online?
Beboere experimenting with spreader rake and diamond tension different then the factory /sailmaker spec, quite some time in the boat or a very broad beachcat experience is a prerequisite for good results in my opinion. This is a very fine grained tuning tool compared to sailing the right lane, boat balanse, helming, sheeting, starting, downhaul, roundings etc. I would run with the factory spec until I had the rest of the skills well done. On our current Nacra F18 that is exactly what we do. The settings are not what slows us down. It is our own boathandling and on the water decisions.

#274054 - 07/21/14 08:02 AM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Dec 2001
Posts: 5,572
waterbug_wpb Offline
Carpal Tunnel
waterbug_wpb  Offline
Carpal Tunnel

Joined: Dec 2001
Posts: 5,572
Naples, FL
Originally Posted by Mpls_Nacra
I find that when racing in light wind I am extremely slow.


When you say "Light Wind", can you give a range (windspeed or Beaufort)?

If memory serves, there was some discussion about laminar vs. turbulent flow breaking at about 8mph and the difference in AWA between surface and top of mast.

Sail settings and efficiency changed based on those parameters


Jay

#274100 - 07/23/14 12:05 PM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Mar 2008
Posts: 55
Mpls_Nacra Offline
journeyman
Mpls_Nacra  Offline
journeyman

Joined: Mar 2008
Posts: 55
Minneapolis
Jay, I would say 7 mph and under.

thx
DF


Dave Foster
Minneapolis
Nacra F16
#274101 - 07/23/14 01:09 PM Re: Slow in light wind [Re: Mpls_Nacra]  
Joined: Dec 2001
Posts: 5,572
waterbug_wpb Offline
Carpal Tunnel
waterbug_wpb  Offline
Carpal Tunnel

Joined: Dec 2001
Posts: 5,572
Naples, FL
then you're overtrimmed smile


Jay

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