What do the experts say is the limit on roller reefing a well-cut 150 genoa? At what point does roller reefing the foresail start to damage the sail, assuming that it will most likely be reefed in stronger wind conditions?
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Bill O'Donovan
Depends
Depends on wind and whether you have the main up. One theory is that reefing the geneoa is like reefing one's pantleg: It looks funny and doesn't improve things much, while distorting the fabric. My rules of thumb: 1. Reef the main first 2. Or pull in the genoa altogether. 3. Or sail solely on the genoa. Try any of these permutations.
Depends on wind and whether you have the main up. One theory is that reefing the geneoa is like reefing one's pantleg: It looks funny and doesn't improve things much, while distorting the fabric. My rules of thumb: 1. Reef the main first 2. Or pull in the genoa altogether. 3. Or sail solely on the genoa. Try any of these permutations.
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RonD
80% Rule-of-Thumb
Bob The "150% Genoa" label refers to the amount the foot extends beyond the main mast. In the literature, many suggest that a sail's shape isn't much good as an airfoil to produce "pull" once you have rolled up more than 80% of the foot. 80% of a "150% Genoa" makes it a "120% Genoa." Sailmakers put foam, etc. in the luff to force the roll-up to leave a more effective shape, but I don't think much is actually gained. You can roll it up further, but it will affect how well the sail drives things. Might result in a larger minimum pointing angle while close-hauled, and perhaps more weather helm. Damage is a whole other subject. Rolling in the Genoa is something we do as the winds pick up, and it tends to reduce the overall stresses on the jib fabric & fittings (less cross-section area) and the jib sheets & blocks. There is also a counter-force acting to try to unroll the sail under those conditions, proportional to sail area and to the effective luff length. I've seen fully rolled jibs become shredded in a T-storm because they weren't rolled tight enough, and/or sufficiently over-wrapped by the sheets, to protect the luff from the wind trying to unroll it. Best to ask the manufacturer of the roller furling mechanism and your sailmaker for advice. --RonD
Bob The "150% Genoa" label refers to the amount the foot extends beyond the main mast. In the literature, many suggest that a sail's shape isn't much good as an airfoil to produce "pull" once you have rolled up more than 80% of the foot. 80% of a "150% Genoa" makes it a "120% Genoa." Sailmakers put foam, etc. in the luff to force the roll-up to leave a more effective shape, but I don't think much is actually gained. You can roll it up further, but it will affect how well the sail drives things. Might result in a larger minimum pointing angle while close-hauled, and perhaps more weather helm. Damage is a whole other subject. Rolling in the Genoa is something we do as the winds pick up, and it tends to reduce the overall stresses on the jib fabric & fittings (less cross-section area) and the jib sheets & blocks. There is also a counter-force acting to try to unroll the sail under those conditions, proportional to sail area and to the effective luff length. I've seen fully rolled jibs become shredded in a T-storm because they weren't rolled tight enough, and/or sufficiently over-wrapped by the sheets, to protect the luff from the wind trying to unroll it. Best to ask the manufacturer of the roller furling mechanism and your sailmaker for advice. --RonD
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Bayard Gross
Move the jib cars forward
When reefing a furling jib, it can be advantageous to move the jib cars to a more forward position to maintian shape in the shortened sail. In fact ideally, you would move the cars all the way forward, furl the sail down to desirable size, and then move the cars back to a point more forward of where they were before furling. This is because the foot is shorter than the leech and with the cars forward, pull on the sheet on the foot is lessened while increased on the leech making it roll more smoothly onto the furler. By having the cars in a more forward position than normal for high winds a sail can be reefed down to storm sail size and still have acceptable driving shape. This sounds counter productive when trying to "spill" wind, but it done properly, it can work well. The trick is to do this while things are piping up which does mean moments of wild flapping while luffing to ease tension on the cars.
When reefing a furling jib, it can be advantageous to move the jib cars to a more forward position to maintian shape in the shortened sail. In fact ideally, you would move the cars all the way forward, furl the sail down to desirable size, and then move the cars back to a point more forward of where they were before furling. This is because the foot is shorter than the leech and with the cars forward, pull on the sheet on the foot is lessened while increased on the leech making it roll more smoothly onto the furler. By having the cars in a more forward position than normal for high winds a sail can be reefed down to storm sail size and still have acceptable driving shape. This sounds counter productive when trying to "spill" wind, but it done properly, it can work well. The trick is to do this while things are piping up which does mean moments of wild flapping while luffing to ease tension on the cars.
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sailing geek
That's some scary advice...
...from Bayard. Sorry, buddy, but you're all over the place. Most sailors simply move the jib leads to pre-set marks that correspond to reef settings marked on the sail. By the way RonD, a headsail's percentage size is not how far the foot goes past the mast. It is the relationship between the LP (luff perpendicular) and the boat's "J" dimension.This is explained in greater detail at just about any sail manufacturer's site. Here's a link to one for the lazy people. To answer Bob's question. I concur with Bill.
...from Bayard. Sorry, buddy, but you're all over the place. Most sailors simply move the jib leads to pre-set marks that correspond to reef settings marked on the sail. By the way RonD, a headsail's percentage size is not how far the foot goes past the mast. It is the relationship between the LP (luff perpendicular) and the boat's "J" dimension.This is explained in greater detail at just about any sail manufacturer's site. Here's a link to one for the lazy people. To answer Bob's question. I concur with Bill.
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Alan
Bayard is correct
As the headsail is furled, the cars need to be moved forward to maintain the correct lead angle. This is where line adjustable cars become very handy. Mr Geek, what most sailors do is not necessarily the right thing. It is true that the size of a genoa is the ratio of LP to J, however if you shorten the foot by any give percent then the LP changes by the same percent. Personally I never furl my headsail, I simply change down to the needed size for the wind conditions. A twin grooved headfoil makes that job pretty easy.
As the headsail is furled, the cars need to be moved forward to maintain the correct lead angle. This is where line adjustable cars become very handy. Mr Geek, what most sailors do is not necessarily the right thing. It is true that the size of a genoa is the ratio of LP to J, however if you shorten the foot by any give percent then the LP changes by the same percent. Personally I never furl my headsail, I simply change down to the needed size for the wind conditions. A twin grooved headfoil makes that job pretty easy.
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