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So...anyone use anything but the middle mainsail clew hole?
http://www.hobie.com/au/en/forums/viewtopic.php?f=13&t=58754		 Page 1 of 1
Author:  TAMUmpower [ Thu Aug 11, 2016 7:01 am ]
Post subject:  So...anyone use anything but the middle mainsail clew hole?
Since there's a traveler car on the boom it can't affect the pull on the foot, only the leech. So what's the deal, would you ever want to adjust the point it's pulling on the leech or is the range of adjustment too small? Or, are there 3 holes just because this was a clew plate borrowed off a parts bin and just happens to have 3?

I've only ever seen people use the middle hole.
Author:  Tom Kirkman [ Thu Aug 11, 2016 7:17 am ]
Post subject:  Re: So...anyone use anything but the middle mainsail clew ho
I've asked the same question to some of my Hobiecat friends and have been amazed to learn that most don't understand what using the sheet hook in different clew positions does. Thus, they just run it in the middle. Same with the adjustable clew plate on many of the jibs. They don't understand the change in direction of pull from leech to foot, so they just put it in the middle.
Author:  mmiller [ Thu Aug 11, 2016 8:58 am ]
Post subject:  Re: So...anyone use anything but the middle mainsail clew ho
On the 18 it has very little if any effect on sail shape. In theory: forward hole would pull aft on the foot and loosen the leech. Aft would pull more down on the leech and less aft on the foot. The hole spacing is minimal. I raced 18s for years and never considered it as an adjustment worth thinking about. Likely it was simply a convenient piece of hardware to achieve the connection when they designed it.

The effect on a Hobie 16 jib clew plate is dramatic. You have 5 holes and at an angle that makes a big difference in sail shape.

On the 18... Jib sail shape is done with jib car traveler placement.
Author:  srm [ Thu Aug 11, 2016 9:15 am ]
Post subject:  Re: So...anyone use anything but the middle mainsail clew ho
Agree with mmiller. In fact, I think on many 18 sails, the other holes were never even punched out.

My opinion, you are better off using the middle hole because you get a more even load distribution across the clew plate rivets, so there's less of a chance of the plate pulling off the sail. The flip side of that is that if you use the same hole constantly, eventually you will wear through the plate and the clew pin will pull out, so keep an eye on the plate on older sails. I know someone who had the pin pull through the plate and got into a bind because only the center hole was punched out, so no way to pin the clew to sail the boat back to shore.

sm
Author:  TAMUmpower [ Thu Aug 11, 2016 9:23 am ]
Post subject:  Re: So...anyone use anything but the middle mainsail clew ho
mmiller wrote:
On the 18 it has very little if any effect on sail shape. In theory: forward hole would pull aft on the foot and loosen the leech. Aft would pull more down on the leech and less aft on the foot. The hole spacing is minimal. I raced 18s for years and never considered it as an adjustment worth thinking about. Likely it was simply a convenient piece of hardware to achieve the connection when they designed it.

The effect on a Hobie 16 jib clew plate is dramatic. You have 5 holes and at an angle that makes a big difference in sail shape.

On the 18... Jib sail shape is done with jib car traveler placement.


Would it really pull aft on the foot more? Wouldn't the traveler car position be the only thing that can change the pull on the foot? If I left the car in the same position then I could see moving the hole changing the foot tension but it seems like the leech is the only thing it would be changing.
Author:  mmiller [ Thu Aug 11, 2016 9:27 am ]
Post subject:  Re: So...anyone use anything but the middle mainsail clew ho
Read...

mmiller wrote:
In theory:


and...

mmiller wrote:
The hole spacing is minimal. I raced 18s for years and never considered it as an adjustment worth thinking about. Likely it was simply a convenient piece of hardware to achieve the connection when they designed it.


and...

srm wrote:
In fact, I think on many 18 sails, the other holes were never even punched out.


So... no real effect if you could even use the other two holes.
Author:  SabresfortheCup [ Thu Aug 11, 2016 12:45 pm ]
Post subject:  Re: So...anyone use anything but the middle mainsail clew ho
TAMUmpower wrote:
Would it really pull aft on the foot more? Wouldn't the traveler car position be the only thing that can change the pull on the foot? If I left the car in the same position then I could see moving the hole changing the foot tension but it seems like the leech is the only thing it would be changing.


I think for a mainsail, you're right about the outhaul being the primary factor in foot tension. On a jib, however, changing the hole on the clew plate changes the angle of the jib sheet, and therefore the angle of the force you're putting on the sail. Pulling down more = tighter leech, pulling aft more = tighter foot, looser leech.

Like mmiller said, on an H18, clew plate doesn't make much difference on the main, and the jib fairlead cars are used to change the angle of the sheet rather than a clew plate. My jib just has a single grommet at the clew! :lol:
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