We're going faster, I think, but why?

NPMR

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We\'re going faster, I think, but why?

We fitted roller furling to our Sabre 27 last winter, Profurl as this was given more thumbs up by Forumites than other brands,

We adapted the relatively new hanked Genoa we had as funds were low. Naturally it got smaller, as they cut off the luff and the mechanism meant that the foot had to rise up to accomodate it. Net effect - sail got smaller and I always felt that the boat was under-canvassed before.

But recent sails seem to show that we have not lost speed, and in some ways the boat is easier to sail.

Why would this be the case, I wonder?
 

exfinnsailor

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Re: We\'re going faster, I think, but why?

Perhaps you had to much to start with .. Sailed a FINN and always thought when jibing you could do with a smaller sail /forums/images/graemlins/smile.gif A bigger sail would have been nice on a Thursday night when the wind died .. Hey Ho .. Happy Sailing .. /forums/images/graemlins/cool.gif
 

Cornishman

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Re: We\'re going faster, I think, but why?

At one time there used to be an awful lot of talk and articles in learned magazines about "The Slot", that is the gap between the mainsail and foresail. It is thought that its shape and size are critical to get max performance, and no doubt there is some truth in that. Maybe you accidentally improved yours by altering the size and shape off your genoa.
 

michael_w

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Re: We\'re going faster, I think, but why?

Perhaps your old genoa was bit of a sack and the re cut has inproved its shape.
 

snowleopard

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Re: We\'re going faster, I think, but why?

Several factors could cause a change in performance. The foil in place of a separate stay and luff wire has probably smoothed the flow. You may also have altered luff tension and sheeting angle.
 

Krusty

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Re: We\'re going faster, I think, but why?

You have discovered a truth about headsails: that bigger is not necessarily better, and genoas can easily be too big!
After its success on dedicated racing yachts the Genoa became a 'must have' for cruiser-racers, then any general-purpose cruising yacht with pretensions for performance: but it ain't necessarily the best match to the mainsail, hull shape and keel performance!
Think of it this way: the function of sails is to bend an airstream to extract momentum from it, creating minimum turbulence and no more than the optimum heeling (since too much heel reduces the effectiveness of the keel, creating more water turbulence and drag as well as more leeway). Tall slots between sails of the right curvature achieve that, but too much overlapping cloth is counter-productive ( for instance every extra square foot adds to surface friction, adds to the difficulty of trimming the shape exactly right, etc.)
Many years ago I discovered that in winds of Force 4 or more, my boat (a superb cruiser-racer in her day) sailed better with a cutter rig than with either of her genoas, and it has become her standard rig: the benefits increasing as the wind gets up and sail area is reduced: we reef and go faster!
Nowadays we only set the No.1 genoa in light winds, and the No.2 genoa poled-out and goose-winged for a long down-wind leg in winds too fresh and seas too rough for comfort with a spinnaker or cruising chute.
You have probably relieved your boat of canvas overload!
 
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