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From www.starclass.org Technical Articles
Q: I have good speed but lack on pointing, what should I do? A: Most of the time pointing problems come from the mainsail being set flat and therefore less powerful. The first control that come to mind is the outhaull and lower backstay. On trying to generate power the outhaull being eased will greatly help create power up the very low sections of the mainsail. By increasing the tiller pressure, making easier to steer in light shift conditions. The next control is the lower backstay, that will make the middle sections of the mainsail fuller and again more powerful. It is possible that the lowers can be pulled too hard and as a result the forestay get too tight. If the lower backstay have to be pulled hard to make the mainsail fuller, the spreader should be moved further forward ( eq. from 5 1/2" to 5" ). Very often I just pull the lower backstay an extra half inch to maintain my crew over the side and keep the boat power up and on the high pointing mode.
Q: How much shroud tension upper should I have? A: The upper shroud tension dictates the amount of pre-bend you will have and how full your mainsail will setup. This is true even in very light winds. I don't pay much attention to how much tension I have on the shrouds but more important, how much pre-bend I have. To measure your pre-bend is very simple. With the boat on the trailer "pop" the mast with the spreaders aft, as you were setup for going up wind. Make sure that lever is off, and upper backstay have only enough pressure to make the forestay snug. Then bring the main halyard shackle to the opening on the mast groove and check the distance from the halyard to the mast as the spreader height. The mast fore&aft dimension is 3 3/4" and I normally set my mast with 4 inches of pre-bend. I think this is a much better way to tune your rig, since this is exactly what will affect the fullness of your mainsail. With the mast stiffness varying a bit, the right pre-bend (the bend that fits your mainsail ) with a softer mast should require less shroud tension than with a very stiff mast, therefore comparing upper shroud tension between boats without comparing mast stiffness is NOT very accurate way to duplicate the setup. Star Boat Rigging Tip: The Star rig have been setup further forward now than ever in light winds and this setup won't work if the jib isn't pull up the forestay. We see often this days crews with the jib tack about a foot above deck. This accomplish two tasks: one that the jib is further up where winds are less affected by the water surface ( surface drag ), therefore making the jib more efficient. Second is that when sailing in strong winds the bow and the pole tip tends to hit the water, and we all know what comes after the pole hit the water. By lifting the jib on the downwind leg, we keep the jib and pole way from the water and the crew the work the waves harder. I have seen lots of boat that have made the jib halyard puller going through the mast partner allowing the jib to be pulled even further up. This is easy control to be rigged up and sure will make the difference on your downwind speed and your comfort zone. © Copyright 2007 by starclass.org |
