SEATTLE Sailing Club Fearful Symmetry J 80, Quick Start Manual, Page: 20 / 34

20
J-80 Tuning Guide (cont.)
In winds between
0-10 knots
the lead position should be adjusted so that the luff of the jib
brakes or backs evenly when the boat luffs up. If it backs in the top first the lead position is to
far aft and vice versa. Halyard\tension should be lightly applied. In really light winds small
wrinkles should be seen running away from the forestay.
In over 10 knots the head of the sail should back slightly before the lower 2/3's of the sail.
This enables the helmsman to steer a much wider and varied angle to the wind. Sheeting
should be adjusted so that the leach telltale above the top batten flies straight aft. This is
good reference for the jib sheet trimmer to look at through the mainsails spreader window.
Just like the mainsail the jib should be flattened and twisted in hard winds. Forestay tension
is increased using the backstay. Halyard tension is tensioned very hard, and the lead position
is moved about two holes back. The upper half of the luff now backs slightly earlier than the
lower half when luffing. In very hard and gusty winds it's probably easier to ease the sheet
slightly to open up the slot between the main and the jib to give a slightly more easily
controlled boat. This also applies in a sloppy sea when twist and drive are an important factor.
J-80 North Sails -Tuning Guide