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d0uglass
Joined: 28 May 2004 Posts: 1286 Location: Bonita Springs, Florida
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Posted: Mon Nov 19, 2012 12:43 pm Post subject: Clew Grommet "Burgers" for Adjustable Outhaul |
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During a few year long hiatus from formula windsurfing I got rid of all my >8.0 sails and most of my jumbo sail accessories, like the little pulley-burgers that you screw into your clew grommet to make it work better with an adjustable outhaul system.
http://www.chinooksailing.com/products/product_info.php?products_id=153
As a cheap alternative for my new 9.5 I've been using a downhaul pulley hook.
http://www.chinooksailing.com/products/product_info.php?cPath=6_66&products_id=152
It makes for very easy rigging- even easier rigging than a fixed outhaul system -but I'm concerned that it might come unhooked sometime when I'm sailing, though that hasn't happened yet.
The other thing that I've just gotten concerned about after looking at some of my clew-mount camera footage is how the pulley hook might be allowing the clew and foot of the sail to twist and flap more than they would otherwise. The Ezzy Cheetah 9.5 is kind of a "squishy" sail to begin with, so I don't want to introduce any additional wiggle that might reduce its efficiency.
Has anyone else notice an effect of different kind of clew pulleys or outhaul attachments on sail performance? _________________ James' Blog: Windsurfing Equipment Size Calculator
http://jimbodouglass.blogspot.com/2010/11/updated-windsurf-calculator-online.html |
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jingebritsen
Joined: 21 Aug 2002 Posts: 3371
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scargo
Joined: 19 May 2007 Posts: 394
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Posted: Mon Nov 19, 2012 4:30 pm Post subject: |
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Interesting question.
I quit using the burgers a couple years ago in favor of a Ronstan double block. I attach it to the clew with a bow shackle, which makes for a very quick and very secure connection. That arrangement does make the boom slightly longer than with the burgers, because, like the downhaul hook you're using, the block is aft of the clew grommet, as opposed to directly adjacent for the burgers.
I don't think this hurts the performance, though. I'm on carbon on the big sails, so the slightly longer boom length does not compromise stiffness -- and I don't think the fact that the clew can deflect off to leward hurts (or even really affects) the sail geometry. To me, the lines never moved very smoothly through the burgers, and the block gives me a much better feel for outhaul pressure. And I set things up so when I'm outhauled to the max, the clew block is "captured" by the boom. So in OP conditions when I need stability, I outhaul completely and the clew can't move, and in UP conditions when I want the sail to inflate and pull in the gusts, the extra movement is actually a good thing. |
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jingebritsen
Joined: 21 Aug 2002 Posts: 3371
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Posted: Mon Nov 19, 2012 4:52 pm Post subject: |
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when pumping, the up and down movement of the back of the boom versus the clew grommet is my concern, not the port or starboard drift when the out haul is loose during a straight run once locked in and planing. the sailors' energy is wasted, and the running rigging gets far more wear. so, in summation, pumping with zero out haul tension is a waste of energy, and can wear the gear out sooner.
it's like the adjustable on the fly down haul that RSX folks use: too loose and the batten tips are broken with very little pay off. yes, one can adjust the D/H to gain some, but one must recognize that too little tension has no pay off and lots of costs....
also, using spectra line for the grommet portion of the running rigging is an option too. maybe try no burgers, no tackle at all. for some folks, raw spectra is slippery enough if one only uses 2 passes thru the clew. _________________ www.aerotechsails.com
www.exocet-original.com
www.iwindsurf.com
http://www.epicgearusa.com/ |
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DanWeiss
Joined: 24 Jun 2008 Posts: 2296 Location: Connecticut, USA
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Posted: Mon Nov 19, 2012 7:33 pm Post subject: |
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James, Tinho developed a great outhaul pulley system that bolts through the clew ring and stays with the sail. It used a pair of Harken or Ronstan bearing wheels and held the line securely using custom plastic "ears." The ears bent 90 degrees to to the sail's plane and served the same intended purpose as those "buttons" on the Chinook but worked with far less friction. Tinho's is the best I've ever used for FW-sized sails.
For sails smaller than gargantuan, I use the Sailworks race system. It's very low friction, is very easy to adjust once set up properly, and weighs next to nothing. All Spectra line, all included, and no actual "hard" hardware. _________________ Support Your Sport. Join US Windsurfing!
www.USWindsurfing.org |
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d0uglass
Joined: 28 May 2004 Posts: 1286 Location: Bonita Springs, Florida
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scargo
Joined: 19 May 2007 Posts: 394
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Posted: Tue Nov 20, 2012 12:01 pm Post subject: |
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I take the point about the boom being able to move up and down, but I don't see how that could possibly wear out my gear. All my outhaul lines run through silky-smooth, ball-bearing blocks -- so chafing is physically impossible, even if I pumped the sail thousands of times. \
As I said, I switched away from the burgers a couple of years ago, and to me it's a much better feel. |
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d0uglass
Joined: 28 May 2004 Posts: 1286 Location: Bonita Springs, Florida
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nw30
Joined: 21 Dec 2008 Posts: 6485 Location: The eye of the universe, Cen. Cal. coast
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Posted: Sun Nov 25, 2012 8:43 pm Post subject: Re: Clew Grommet "Burgers" for Adjustable Outhaul |
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d0uglass wrote: |
Has anyone else notice an effect of different kind of clew pulleys or outhaul attachments on sail performance? |
Hea, I'm just a wave sailor with some bump and jump in my distance background as well as some big sail, flat water stuff, which brings me to this question.
The bigger the sail, the easier it is to outhaul, so why the outhaul pulleys or outhaul attachments in the first place?
There is nothing more efficient than having your sail clew all the way to the clew end of the booms, no nothing added to introduce wiggle.
There is beauty and efficiency in simplicity.
Note of reference (for what it's worth): The biggest sail I have sailed is a 7.5 Aeroforce (I know, somewhat historic), I had it tight to the clew, I was flying, and the sail was solid.
But I feel the basics haven't changed, plus you could shorten your booms even more. |
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joethewindsufa
Joined: 10 Oct 2010 Posts: 1190 Location: Montréal
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Posted: Mon Nov 26, 2012 4:49 am Post subject: |
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personally use adjustable outhaul on my sails larger than 8-oh
these sails are used in winds under 20 knots - typically
so, let's call them "light winds"
letting out the outhaul just a little can at times be the difference between planing and schlogging - you can always pump, butt will planing be sustained?
for downwind it is more efficient to have a full sail and thus you can let out the outhaul
for upwind a flatter sail is better and you can tighten the outhaul
in summary - it gives you more range without having to go in and make adjustments
if winds are steady there is obviously less need as well
personally i have NOT felt the clew end of the sail shake about like in the video, butt will not be sure until i put a GOPRO there myself
apparently racers swear by adjustable outhauls on the larger sails ... |
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