H41 genoa size

[Valerio]

i have a jib with a luff of 580 inch, leech of 547 and foot of 196, i think is like a 95% jib, how big i can go before hitting the spreaders ?
also my foot when unrolled is almost 7 feet above the deck, is your similar ? what is your genoa size ?

 

[Nodak7]

If it is the stock Genoa it is 110%. You can go bigger but it becomes an issue with the standing rigging. Here is the sail measurements

 

[Valerio]

Is what i am trying to figure out, i have the same tecnical sheet but i thinks is wrong because the J dimension of my sail is 4950 mm and is not touching the spreader and the tec sheet say 3962. i think that is not correct.

 

[Nodak7]

Do you have a picture of it deployed? Look at mine and see if it is similiar!

 

[Stu Jackson]

LP = luff perpendicular

Whatever your foot, luff and leech dimensions are are immaterial, you need to figure out what the LP is.

Only YOU can do that based on the info you posted (I'm not doing your trig for you today, but I betcha could do it with apiece of graph paper).

 

[Valerio]

look like mine

Do you have a picture of it deployed? Look at mine and see if it is similiar!

Look the same size

 

[Valerio]

not close reach, Nodak7 i cannot see how high is the attachement of the jib sheet on your boat, mine is almost 7 feet, good for visibility but i think is too much.

 

[DrJudyB]

i have a jib with a luff of 580 inch, leech of 547 and foot of 196, i think is like a 95% jib, how big i can go before hitting the spreaders ?
also my foot when unrolled is almost 7 feet above the deck, is your similar ? what is your genoa size ?

Hi @Valerio,

I did the math for you. The LP is a little bigger than 184,85” or 4695 mm. J for the Hunter 41 is 3960 mm, I believe. So that makes the overlap percentage approx 119%.

Based on our experience building sails for that boat, I don’t think you can build a sail significantly bigger without having the leech hit the shrouds.

(I did the calculations in 2D as though the jib were a flat triangle with straight edges, which it isn’t, so there is some error in my estimate)

 

[DrJudyB]

This pic is from sailboatdata.com . I would guess that it's close reaching or close hauled in moderate wind. That's just a guess.

The clew height is a very common height for a cruising jib for this boat, because it's a good compromise between pointing and reaching. If the clew were significantly lower, it would point a little better, but the leech would twist open when you ease the sheet outboard for reaching.

As you ease the sheet for reaching, you probably need to push the genoa car forward, to keep the leech from being too open at the top. Too open means it's not producing as much power as it could. (too open = too small an angle of attack for max power, almost luffing). Remember to move the genoa car forward to close the leech while still keeping the upper tell tales flying, particularly in in light winds.