Fractional Rig Tuning
Hi JakeIf you have a fractional rig (forestay attaches to mast below the masthead and swept back spreaders) then you need to reduce the variables and basically make the rig tight with a straight mast. When you get your rig set up, is the mast straight? Lie on the deck with your head just aft of the mast base and sight up the mast. You can expect to see the mast leaning aft, called mast rake. You can put a plumb bob on the main halyard and actually measure the rake in inches, but subtract the distance the main halyard sheave is holding the plumb line from the actual back edge of the mast. On my 26D I have approx 6 inches of rake.To adjust rake, you are basically going to need to cut your forestay or make a longer new one. The turnbuckle on the forestay may slightly affect rake, but requires a lot of other adjustments to the sidestays to actually do anything, so if you intend to use your current forestay, your rake is already determined for you by its cut length. Here is how I tune my rig. I remove the backstay completely (more on that later). I pin and tighten the forestay turnbuckle to mid range on the tbuckle travel. Now I start to tighten my sidestays. The sidestays need to be tightened equally to keep your mast straight. You may need to either tighten one side or loosen the opposite side to remove a bend. As you tighten the four wires of rig this way, the spreaders will haul aft on the mast and the rig will stand up nicely. When the rig is tight and the mast still straight, the rake you have is the rake built into the forestay wire length.How tight? The tightness of your rig will determine (among other things) how well your boat points to windward. The downside is that high tension accellerates wire wear and possible damage to the stay attach points. Slack wires are very dangerous due to snap loading as the loose wires load and unload. The rigs on D models I've seen that were tuned for fast sailing to windward (and my own D) are somewhat difficult to pin at the forestay even with the tbuckle completely loosened. The Backstay. The backstay is unnecessary to stand up the fractional rig on our boats. I have an adjustable backstay which I made from a small block and tackle. I shortened my backstay about 4 feet and swaged in an eye to attach the top of the block and tackle. I do not attach the backstay at set up time to keep the pesky backstay wire from snagging on the parts on the back of my boat. After I pin the forestay and tension the tbuckle, I set up and tension the adjustable block and tackle on the backstay. Good luck and post pics John S