2009 Sunfish N.A.'s Race One Helmet Cam video - edited

C

chucktowncolie

New Member
I raced the 2009 Sunfish North Americans with my helmet cam filming. Here's the link to the edited version of Race One. Hope you enjoy it.

 
Although I'm not racing my SF I still want max performance out of her, and I noticed on the video that one end of the shock cord appears to run from the daggerboard to the join of the spars at the tack, the other end appears to be tied to the mast, am I correct here? Good video by the way.
 
The shock cord is attached to the spars and goes around either side of the mast. I attach it to the daggerboard with sisterhooks. It is not tied to the mast.
 
That's great, thanks. I got the SF new in 07 and it came with a length of shock cord and a couple of sister hooks but the manual didn't clearly state how the cord was to be attached.
 
Zeppo said:
That's great, thanks. I got the SF new in 07 and it came with a length of shock cord and a couple of sister hooks but the manual didn't clearly state how the cord was to be attached.
Click to expand...

The idea is to rig the shock cord so that it will pull the main out when going downwind in light air.

Perhaps more useful, is the pressure on the daggerboard holds it in any position from fully down to fully up, or anywhere in between.

This shock cord attaches to the daggerboard, goes around the mast and the notch between the two spars--the tack.

Since the shock cord is hooked to itself, what is the other side doing? It has a longer path around the mast to the tack, so it is under more tension. We want the tension on the side that will pull the tack back and pull the boom forward. So how do you do that?

Well clearly, you must increase tension on the side going to the tack from the daggerboard and decrease the tension on the long side, going around the mast to the daggerboard

You have to tug on one side of the other to make the shock cord come under increased tension--letting it slide around to the long path side. More length on the long side means less tension. What you are doing is moving a portion of the shock cord from one side to the other. The side under tension is stretched more than the side not under tension.

There has to be tension on the side going to the tack, and the side going around the mast should be under less tension. When the tack is pulled back, the sail goes to 90 degrees to the centerline of the boat--i.e. it holds the sail out.

There are various ways to hook it up. On my wooden dagger board I install a bronze cabinet handle for lifting purposes.

I run the shock cord through this handle. The shock cord could be fixed here, or fixed at the tack. The rest of it can slide around. When it is fixed at the daggerboard, I find it can jam in the tack and that is hard to reach in a hurry. I'm not sure, but I think most people secure the shock cord at the daggerboard.

In my case I have had good success letting it slide though my bronze dagger board handle and leaving it secured at the tack. An extra turn(a round turn) around my bronze handle adds more friction and holds it in place. I tug on the side I want tension. It slides though to the other side, loosening the other side. Then friction holds it in place.

Alternatively, as shown in the video, it can be fixed at the daggerboard and you would pull on the long side to pull more of the shock cord to that side--increasing tension to the tack to daggerboard side, and the extra length on the long side will decrease tension there. Voila, the sail goes out in light air.

I've seen daggerboards with holes in the front edge. I suppose the shock cord could go through here and fixed at the tack. The friction of the shock cord passing through the daggerboard will hold in roughly in place and allow for a quick adjustment if necessary. I like my method for a wooden board, because they are sometimes hard to pull up. The bronze handle works great for me.

So, the side under tension pulls the tack back and the sail stays full when sailing downwind--even in light air.

Note that in heavy air. The main purpose of the shock cord is to hold the daggerboard up when sailing downwind. The wind would be strong enough to hold the sail out.
 
The colored sails aren't rec sails - they are sails specially made for a particular Sunfish World Championship event. They are "special edition" race sails, that's why you see them in the race. They come with event boats - there are boats made specifically for the World Championships, they get used for the event, then sold. My boat is from the 2006 Charleston Worlds, I've changed to a white sail, but you can see the trademark yellow racing stripe, and the 2006 logo sticker on the boat.
 
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