Can you lucky 500 owners measure your bridle wires for me, eyelet to eyelet? Let me know if its a Fun School or Race model, not sure if that will make a difference.
Murray's probably knows the size and can make you one. It's probably longer on the 500 because the jib tack is higher. It has to be to get the right sheeting angle because the jib blocks are mounted on the main beam on the 500. This frees up the tramp but you can't change your sheeting angle fore when you're sailing and it also reduces the luff length. The best way to way to adjust the sheeting angle is to set the jib a little higher or lower. A few inches either way will give you all the adjustment you need. Leave enough length between between the end of the forestay and the apex of the bridle to make this adjustment. The clew plate on your new jib should have three holes and that will give you some adjustment. Make sure the luff of your new jib isn't too long. Don't use a shroud adjuster, just loop 3/16 between the two and this will also easily enable you to get enough purchase to get your rig tension. Give careful consideration to how you mount the jib blocks, unless you add a short length of traveler track like on a Hobie 16, you will have no port/starboard adjustment. If it were me, I'd leave the jib set up the way it was designed for the 5.0. Changing to the 500 jib set up will not increase performance.
NacraSailing.com says the N500, N570 & N580 use the same bridle. Doesn't give dimensions, though. It also mentions 2 versions of the forestay, with a bridle ring & without?
-- Chuck Miles
1978 Hobie 16
1991 Hunter 23.5
TsaLaGi Yacht Club, Jackson Bay Marina
Fort Gibson Lake, OK --