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Optimist Tuning Guide from UK Sailmakers

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Optimist Tuning Guide from UK Sailmakers Optimist Tuning Guide from UK Sailmakers There is no precise answer to how your new Optimist sail has to be trimmed. It depends on several factors, among others; � The sailors weight � The sailors psysical strength � The sailors technique Below is a detailed review of the different trim options, and our suggestions for setup under different conditions. On the Optimist you have the following trim options: � Sail ties in luff and foot � Luff tension � Sheet � Outhaul � Kicking strap � Bridle � Sprit � Mast rake All of these things can be trimmed on the water, but it´s a good idea to set up the trim when you´re preparing the boat on land. Remember that there are almost always more wind on the water than on land! Sail ties in luff and foot Normally you don´t need to adjust the sail ties in the foot. Tie them leaving about 9 mm between the sail and boom – this way the sail will easily pass the boom fittings. Remember that the sail must not be more than maximum 10 mm from the boom and mast! In the luff we recommend that you run your sail ties twice around the mast – this makes tuning more accurate. The following measurements are indicative and not appropriate for all types of masts. 0­6 Knots Your sail is designed with very little luff curve. When sailing in light wind you will have no mast bend because of the light sheeting. Tie your sail 9 mm from the mast all the way – this way you get your sail as far from the turbulent area behind the mast as possible. 7­14 Knots The mast will now bend slightly. In order to maintain the sails designed shape, tie like this – measured from the front edge of the sail to the mast; Throat – 3 mm 5 mm 7 mm 9 mm 9 mm 7 mm 5 mm Tack – 3 mm 15­22 Knots Because the sheet will be pulled hard, the unstayed mast will bend and the sail will misshape. If you still can balance the boat, tie like this – measured from the front edge of the sail to the mast; Throat – 2 mm 4 mm 6 mm 8 mm 8 mm 6 mm 4 mm Tack – 2 mm 23+ Knots Since you probably can´t balance the boat upwind, let the mast flatten your sail. Tie like this – measured from the front edge of the sail to the mast; Throat – 9 mm 7 mm 5 mm 3 mm 3 mm 5 mm 7 mm Tack – 9 mm Luff Tension When the kicking strap is tightened, the luff gets tight. You can ease the tension in the front of the sail by twisting – and hereby shortening – the goose neck strap, making the luff fuller. 0­6 Knots Going upwind, let the luff sag a little between the rings in the luff. Make sure that the measuring mark on the sail doesn´t come up too high on the mast! 7­14 Knots Going upwind, let the luff sag just a little between the rings in the luff. Make sure that the measuring mark on the sail doesn´t come up too high on the mast! 15­22 Knots Going upwind, remove any sag between the rings in the luff. If you have problems balancing the boat, remove another twist from the goose neck strap. By doing this, the draft will move forward and flatten the leech. 23+ Knots Tight luff. The draft will move forward and flatten the leech. Sheet 0­6 Knots Sheet the boom app. 8­10 cm outside the corner of the boat. If you need to point higher, e.g. in a start, you can briefly sheet to the corner. But keep an eye on your speed relative to your competitors! When you have clean air, sail low and fast. The lack of height is won again in better speed and less drift. 7­14 Knots Sheet the boom to the corner of the boat. If you need to point higher, e.g. in a start, you can briefly sheet a little harder, but keep an eye on your speed! 15­22 Knots Sheet the boom to the corner of the boat. If you have problems balancing the boat, loosen the sheet a little – this will twist the leech and depower the sail. 23+ Knots Sheet the boom app. 5 cm outside the corner of the boat. This will twist the leech and depower the sail. Outhaul 0­6 Knots To power up the sail, let the foot sag a little between the rings. This will also allow the sail to flop over the boom easily when tacking. 7­14 Knots Flat water: Like above. Waves: A little looser outhaul for more power. Make sure not to loosen the outhaul to much; this will make the sail stall, which is slow. 15­22 Knots No sag between the rings in the foot. 23+ Knots No sag between the rings in the foot. Don´t pull the outhaul more than this – this will misshape the sail and the power will be unbalanced. Sail perfectly trimmed. Note the sag between the rings in the foot…… Kicking strap The kicker controls the leech tension, how much your sail twist. Too much kicker and the leech is hooked and stalling the airflow – too little and the boom lifts, the leech twists and depowers the sail. The kicking strap should always be adjusted to take up any slack in it, once the sail has been sheeted into its normal position for beating. As the breeze builds, the mainsheet is pulled harder to keep the sail in the beating position and so more kicking strap tension is required. Going downwind you need a little twist in the leech to get airflow around the sail, but be careful; Too little kicker going downwind can force the boat to roll to windward, easily resulting in a capsize. The kick tension should be altered around the course as you race, when conditions change. Nice downwind trim. Note the small twist in the sail – you need airflow around the sail to go fast! Bridle 0­6 Knots Push the ring forward compared to the block in the bottom of your boat. You have very little sheeting pressure and you´ll have more space in your boat for roll tacks. 7­14 Knots The ring should be right above the block in the bottom of your boat. 15­22 Knots The ring should be right above the block in the bottom of your boat. If you have problems balancing your boat, move the ring a little aft – this will make the boom push the mast forward, resulting in more mast bend and more twist in the sail. It depowers……… 23+ Knots Move the ring a little aft – this will make the boom push the mast forward, resulting in more mast bend and more twist in the sail. Sprit The sprit is the most important trim tool in an Optimist, and should be trimmed immediately when conditions change. There are a few simple rules you should always follow; ­ Never sail with vertical creases! This means the sprit is too tight, and the vertical creases kills the airflow and the sails performance. This often happens in light wind, if the sprit is not eased for the reach and run. ­ Horizontal creases appear when the sprit is too loose. This isn´t as bad as vertical creases and often it´s faster than a “perfect” trimmed sprit. In very light conditions it´s often a good idea with a loose sprit since this creates a better airflow. In heavy air, if you have problems balancing the boat, you can loosen the sprit a little – this will depower the sail. The sprit tension should always be altered around the course as you race! Perfect balance going upwind ­ note the horisontal “speed creases” from a loose sprit Mast rake Before going on the water you need to check your mast rake. This is done by measuring the distance from the top of the mast, to the lower edge of the gunwale ­ just above the rudder fitting. Remember to pull your sheet for upwind when measuring! A good starting point is 280 cm, depending on your weight. Once on the water, it´s time for fine tuning the mast rake. Trim your sail and sail upwind – remember to sail the boat flat. If the boat has a tendency to luff up, you need to trim the top of the mast forward. If the boat wants to bear away, you need to trim the top of the mast backwards. If you´re a very experienced sailor you can trim the boat neutral, but normally you want a slight weather helm. A sailor typically adjusts his mast rake within 5­7 cm, depending on the strength of the wind and the waves. Good luck with your new sail! .
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