I just exchanged emails with a sailmaker regarding a new main. He does not have templates for the 5.7, but does for the 570. Are these going to be directly compatible?
More specifically, are the leech, luff, and foot the same?
Yes, the mast and general specs for the 570 and 5.7 are essentially the same. The difference is that the 570 sail is likely a fat top vs a pin head. What does this mean? More power and likely better light air performance. The downside is that its a little more difficult to depower and the main is optimized for a blade jib. So even more power with a full size jib. Its generally viewed as an upgrade, and if it were me i'd go for it. However if you are just learning you may want to think twice.
In other words it will fit.
Dave Bonin
1981 Nacra 5.2
Thanks, the only other thing I can think of is where the down haul attaches. It looks like the 570 down haul attaches right at the tack, but on the 5.7 it attaches up by the bottom batten. I'm sure that's an easy mod.
Edited by tnell on Aug 16, 2016 - 08:41 PM.
Likely no mod at all it just attaches lower so less throw. You may have to move the pad eye and cheek block down a bit if you want more downhaul to depower. I actually double my 5.7 by passing a line from the top of the block to the other side of the mast through the cringle to give me 6:1.
Dave Bonin
1981 Nacra 5.2
I'd go for the square top main and a furling jib setup for the best of both worlds! I can help you get the furling setup on the cheap. Based on lots of regattas and inland lake sailing its about 75/25 Light-moderate to Heavy air.
Well the other sailmaker has the patterns already. Tim, we can talk about the roller setup soon. That is def a priority over anything new.
More specifically, are the leech, luff, and foot the same?
I have 3 factory 5.7sails, (Skip Elliot), & they are all slightly different sizes. The chord varies by 3", & in some places more as you travel up the leech.
I'm not 100% sure, but I think the 5.7,(with the higher cringle), is solely due to a sweeper panel being added to the bottom. The 5.0 cringle is right at the tack.
Remember, you can't use a massive down haul on the 5.7,the sail is only held by that little copper slug on the halyard wire, & you don't have a bendy noodle mast. That said, a slight luff difference won't matter. If the foot is much longer, you end up hitting block-2-block to early. This is detrimental, boomless likes sheet tension, lots of it upwind.
Furling is your friend. I have come home 35 miles from the other side, on a broad reach, under main only in a blow. It handles fine. Solo, at 25+, you will be overpowered no matter what you do. Just travel out, you can sail at 18mph under main only, with nary a telltale properly streaming, but you won't go swimming.
E C Hilliard
Nacra 5.7
Bombardier Invitation
Make your down haul look like this. Just drop the "S" hook into the cringle, pull the tension you want, the jam block holds the line.
http://www.thebeachcats.com/pictures?g2_itemId=119565&g2_imageViewsIndex=1
E C Hilliard
Nacra 5.7
Bombardier Invitation
Thanks Edchris, the previous owner installed a down haul with more purchase. It has what I'd call a W hook with a double block on each side at the tack cringle, one turning block at the center of the mast right a the base, a cheek block on each side right at the base, and a block with a cam cleat on each side just a bit higher up. I'm not sure what the purchase works out to be, but it is adjustable from either side of the boat. There's enough line for the crew to adjust it while on the wire I think.