MacGregorSailors.com

That would depend on the furler foil slot, wouldn't it? What furler do you have?

Neo wrote:So is there a compromise .... 130% ???

You can fit a 100% or a 150%, and that's all. It's not possible to fit a 130% genoa on a Mac 26M or X unless you install custom fabricated genoa tracks, similar to what Highlander did.

The jib is not a 110%, it's a 100%.

And the tape is a #6 if you have a CDI furler installed.

Judy B
HydeSailsDirect.com

kadet wrote:Neo if Central Coast is like up here in the Sunshine State i.e predominantly SE trades 10-15 knots with afternoon NE at 15+ I found the 150 overkill and went for a 110 with a spinnaker for the very light days.

So just to confirm .... If I go for 110% I'll have to sheet it to the cars either side of the mast and run them back to the cam cleats next to the the winches ... Is this correct?

If I reef the Genoa do the cars cover the change of angle well?

Thanks for you help with this.
Neo

Tomfoolery wrote:That would depend on the furler foil slot, wouldn't it? What furler do you have?

I have the CDI FF2 .... Thanks for replying so quickly Tom

Judy B wrote:And the tape is a #6 if you have a CDI furler installed.

Thanks Judy ... you really know your stuff

Judy B wrote:And the jib is not a 110%, it's a 100%.

Can you please clarify? ... Your mean the Genoa right?
The dimensions Kadet gave are 100%? .... Or I need other dimension for 100%?

All the best.
Neo

Here is the original factory drawing for a 26M jib
Kadet's dimensions are shorter on the luff, longer on the leech and foot, and bigger in terms of area by 12 square feet. The LP is 3.39 meters (11.2'), so it's technically a 110%.

To sheet to the cabin top decks, and to avoid hitting the shrouds when the the sailmaker dropped the head by 5 inches, and put a significant hollow in the luff.

I would expect that Kadet's custom jib works just fine. It might point a tiny click lower than the OEM design, due to the shorter luff --> reduced overlap with the mainsail -->> therefore reduced upwash interaction between the mainsail and jib.



From Kadet's post
Leach A (m) 6.8 / 22.31'
Foot B (m) 3.8 / 12.47'
Luff C (m) 7.6 / 24.93'
Area of Triangle (m²) 12.89936

The size of a headsail is how the sail's LP compares to the boat's J measurement.

The J is the horizontal distance from the forestay tang to the face of the mast.

The LP of the sail is measured by taking a line through the clew, intersecting the luff at 90 degrees (LP = Luff perpendicular).. so if that measurement on your sail is 4M for a 100%; 6M will be 150% etc....

I had mine custom made by a sailmaker to fit the largest headsail on my setup of the deck mounted tracks and new raised alloy furler which worked out at about a 108 which is a not a real size so for convenience I just use the term 110

A sailmaker knows what to do just give them the P and J measurement or in this day and age the boat make and model and they will work it out on the computer .

This is the only thing I could find with the headsail in it.
https://goo.gl/photos/ST4ATmvfvwVZG4h46

What Judy B said

Neo wrote:

Judy B wrote:And the jib is not a 110%, it's a 100%.

Can you please clarify? ... Your mean the Genoa right?
The dimensions Kadet gave are 100%? .... Or I need other dimension for 100%?

The common parlance is a 'jib' is 100 or 110%, and uses the fairleads on the cabin roof for the sheets. The 'genoa' is 150% or thereabouts and the sheets pass through fairleads on the cockpit coaming. There may be a more technical distinction, but that's how the terms are used here at least.

I believe a genoa is still a jib (genoa jib), but it overlaps the main so it gets an additional identifier.

Or is that not what you were asking?

The exact same jib is used on the 26X as the 26M by the factory.
The LP for the factory jib is 9.58 feet, when the edges are drawn in 2D (according to the geodesic edges).
A real sail has draft built into it (3D shape). The LP is measured to include the curved of the draft, and would be a percent or two bigger than 9.58 feet -

The commonly accepted value for J on both the M and X is 9.7 feet.
That's makes the LP% on the jib = 100%

But maybe, the published J values are wrong? Maybe they are different between the two boats, or are just plain wrong?

REQUEST: Could a couple of 26X and 26M owners please measure J?
J is the HORIZONTAL distance from the forestay chainplate (where it intersects with the deck at the bow) to the front of the mast, with the mast up.
If the boat is on a trailer, first use a bubble level to get the cockpit seats level from front to back.

PS, the picture below has a slight flaw. It shows measuring J from the corner of the sail. That's wrong. J is a rig measurement, and should be taken where the forestay or chainplate intersects the deck at the bow.

I get about 116.5 to 117.0 inches using a cheap little tape and a plumb bob made from sail thread and a link plate for weight. That's measured to a point on the deck where the forestay line would intersect the deck if it was extended all the way. The measurement would only be a little shorter if it stopped at the stem fitting pin, which is the low end of the range I gave. The high end is the projected point of intersection.

Sounds like the 9.7 ft you've been using is correct. I don't know where Mauripro's site got the J=10.0 ft.

Pretty sure my M was 3 metres for the J value when measured for my Jib which is 10 feet. When I get a chance I will remeasure.

3 meters is 9.84 feet, not ten.

The difference between 9.7 and 9.84 is about 1.8 inches. Would that make an important difference in this “J” value? Just asking.

Ray

Here is the calculation

1 meter = 39.37 inches, so 3 meters = 118.11 inches

9.7 feet x 12 inches = 116.4 inches

So 118.11 inches - 116.4 inches -= 1.71 inches or 43.43mm (1.71 x 25.4)

So a bit over 1% and we are all looking for that extra 1%

I now convert that to sail area od the jib and Im sure that would make a difference

Only to the anal

Ray

Thanks Guys ... This is turning into a real education

sailboatmike wrote:So a bit over 1% and we are all looking for that extra 1%

For me it's much more importance that the sheets hold the Genoa/Jib at the correct angle. So I don't mind losing 1% to achieve that