Has anyone out there with a 5.7, or other nacra with 2 sheave masthead, switched the main haulyard to return down the luff track of the mast? It looks like it may work with the original 2 sheve mast head.
The reason I am posting this is I am thinking about adding a mylar main and more downhaul and I am not sure if the small fork style haulyard hook will handle the tension. So am also thinking of adding a 5.9 ring and hook.
This should also produce a weight savings and less windage.

Yes, azcat, I did exactly this about 3 months ago. I love it. Getting rid of the old halyard in front of the mast, with its noisy banging around is a relief.
Actually, after I bought the whole setup from the dealer, I relaized I had the masthead piece already. So I actually have a spare masthead piece, if you want.
You need three thing to make it work :
1. Masthead casting with sheave.
2. masthead hook
3. halyard ring/shackle.
Don't worry about the forces, it's designed for it. You're right, that stupid little fork this on the front of the mast is by far the weakest part of the system, you'd be getting rid of it for something much stronger.

Jim
5.7 Wind over Water

So.... How much would one guy in the very exclusive and tight knit 5.7 club charge another member for these common ordinary parts?

I will also need a block at the bottom of the mast on the front beam, right?

By the way, I worked on pushing down the bows and found that I did point about 10 to 15 degrees higher, works great. Had to watch the rudder cavitation though. You guys are right on the money!!
Thanks!

I had to add longer rudders to fix the rudder problem. After carefully watching the process I'd call it "aspiration", not cavitation. I could watch air channel down the leading edge of the blade and exit about 4 inches up from the tip. The blade "stalled" suddenly and the boat would round up with no available steerage. Going to longer blades was an instantaneous cure. Fortunately, this was on a Mystere 5.0 and blades from a Mystere 6.0 fit perfectly. Here's a photo (I hope)

HEY... ISN"T THAT MY RUDDER??? GET YOUR HAMMER OFF MY RUDDER!!!!

You must be a shoe maker with a hammer like that.

I wonder if I could extend the leingth of mine with fiberglass. If anyone has done this let me know.

Yep, that's a blade that you got with the M5.5. I origanally acquired it for my M5.0 "bag-o'-extras". Allie Mims now has my old M5.0, you have the M5.5, and I now am collecting Nacra parts. For some weird reason I seem to have a stack of Hobie 20 rudders and boards. My garage justs sprouts extra stuff. Sails falling off shelves, boxes of blocks, etc; I need packrat therapy! Eight boats in ten years...like notches on a gun.

I get porn spam about extending mine all the time!
I never thought of using fiberglass, however.

Oh, you're talking about your boat's rudder, not your rudder. Sorry.

My spam was all mixed up! it said:

Increase the size of your mortgage!
Your $*!&$ has been approved!