Spinnaker Size and cloth weight

[Island Time 1,240]

OK, so following my "issues" in the coastal, I've been thinking a bit about a smaller heavy Kite. Rig dimensions are

I 14.34m

J 4.14m

 

What size is normal for a heavy kite, and what weight of cloth? I'm looking for something suitable 2nd hand if possible.

[Fish 0]

I would say 1.5 oz or heavier, for a "heavy runner".

The size question is a little like "how long is a piece of string".

Smaller than your big light one, but the question is possibly more around how fast do you want to go, how easy do you want it to be able to handle, and what wind range do you want to fly it in.

Obviously the smaller area gives lighter loads / easier to handle, but will go slower.

 

There is one on Sailbrokers that maybe in the right ball park, 

http://www.sailbrokers.co.nz/spinnakers.php

Check out SP 9, its approx 13.4 m luff and 7 m foot, 2.2 0z starcut (i.e. not a saggy old cross cut). Listed as average condition, but the price is suitable for mucking around with.

 

The luff is much shorter than your I, but that gives a small enough 'chicken shoot' for your purposes.

 

Note I'm not a sail maker, so I'm sure someone will be along shortly with more informed advice.

[Island Time 1,240]

Hi Fish, yeah, I saw that one. I'm not sure that his Average and mine are the same! As you say though, might be worth a go...

[Fish 0]

Yes, I would say 'average' is fairly average. The 'rating guide' indicated 5-10% life left.

 

To give you some context around size, my heavy runner is 14.5 m luff by 8.1 m foot, on an I of 12.1 m and a J of 4.8 m.

It is a nice heavy runner for mid to high 20's with the odd low 30's, but only fully crewed. Its a big sail to be handling solo. This would have been mint in the Coastal on Friday. Have gotten away with this in those wind ranges two up, but when things go wrong the loads are right up there for recovering.

 

 

[Island Time 1,240]

Interesting. I must measure my big kite...

Your one in the pic looks still pretty full... Sounds to me like that 2.2 oz one could be a good size for solo in the conditions like we had in the coastal. I think I'll go have a look at it.

[B00B00 310]

I would think 1.5oz is plenty. 2.2 would be pretty heavy and hard to handle.

Normally a kite is around the same luff length as your ISP (halyard height off deck) and your foot is 1.8 x your spinnaker pole length. However in NZ some of the race boats have seriously oversize spinnakers. If you go too small it gets unstable sitting so high off the boat. It's normally the shoulders and mid girth that vary alot between a full size and a heavy kite although some people do have really small chicken chutes.

also you don't want anything too flat. Flat sails can be hard to trim and unforgiving.

[Island Time 1,240]

Thanks Booboo, I did wonder what effect a shorter hoist would be. So 1.5 oz and 14m hoist with about a 6.5m foot sounds about right then.

I was also thinking that the fast boats have lighter loading on their kites flatter off, for a given wind speed, so I guess that effects the cloth weight as well.

IE in a 25 Knot wind a boat that can do 18 knots downwind has less weight of wind in the kite than one that does 10 knots, for example.

[B00B00 310]

Yes but it's generally hoists drops and Wipeouts that ruin kites!

[Island Time 1,240]

True that!

[all fired up 6]

Yes but it's generally hoists drops and Wipeouts that ruin kites!

and gybes !. We tore our dodgy -on its last legs- fractional during a very averagely executed gybe last night.

 

Looking to buy another that will work as fractional on my boat. Does anyone out there have a 1020 (or MRX) kite that is surplus to needs?

 

a.f.u