Genoa Trimming-telltales?

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Mings74

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Hi all,
I was sailing yesterday on my UFO31 with full 140% genoa and mainsail up. I was on a port tack in about 5 knots of wind. Initially I was making about 3 knots of boat speed, however I then had a play around with the backstay adjustment, genoa cars, and the genoa sheet itself. I managed to peek at about 4.5 knots boat speed which I was pleased with.
My question is....what else can I do? (if anything). I could not get the telltales streaming together, am I doing something wrong?, or was it the tack I was on?. Or are the telltales not that important anyway?. Can anybody body recommend a good website about genoa triming or teltales?. Thanks. Ming
 
Top windward tale breaks - move fairlead forward
Bottom telltale breaks - move fairlead backwards.

(This taken from "Sails" by Jeremy Howard-Williams, published by Adlard Coles. Better than a website, for me, as I can take the book to the boat and out on to the water!)

Seems to work well for me and gives me more control than any other type of messing about with the other bits of string, such as halyards etc.
 
I think you are doing exactly the right thing when you say you're playing with the sail trim. The Ufo 31 is very responsive and will tell you through the tiller when you get the combinations right.
The only thing you didn't mention was halyard tension, that can have a considerable effect.
It's possible to get the trim spot on in theory but still lack power.
A very common fault is to have the leach too tight and choke the flow, it's often better to pull cars aft a bit to open the leach slot. But mainly keep experimenting 'til it works.
Excellent choice of boat.
 
It should be possible to get the telltales streaming together a lot of the time in smooth water. Also bear in mind for maximum speed you need to trim both sails to complement each other so it's not just genny trimming you need to look at.

I can't remember any comprehensive web site on sail trim, but I've found various ones in the past through web searches.

The best book by far (IMHO) on sail trim is the North Sails book "Trim". It's aimed at racers, but don't let that put you off. If you know what you need to do for optimal performance you can then decide how fussed you are to do it for cruising at any particular moment.

There's also a book called Jib trimming an illustrated guide by Felix Marks. I didn't learn much new from that, but that was mainly because I'd done a lot of race trimming before I looked at it.

The main things with the tell tales is how much twist you have in the headsail. If the top of the sail is too far out, more sheet tension and maybe move the cars forward and if the leech is too tight do the opposite.

When the boat is pitching, you'll never get the trim perfect as the top of the mast is alternately moving faster or slower than the base, so you have to choose the best compromise. Occasionally things like wind sheer mess up the whole thing, but that's not that common.
 
The telltales are important. That's why they're there!

In addition to the comments by other posters ...

I assume the telltales were put on by the sailmaker? If so they should, theoretically be in the right place. Too far forward or aft and they won't give you the information you want.

They also won't fly evenly. The inboard telltalle will probably lift and fly at an angle of up to 45 degrees above the outboard one, which should be flying straight aft (i.e. parallel to the water).
 
Hi Mings74,

you should take note of both the inside and outside telltales at all times.

What Uforea is referring to is a bit more of the advanced stuff. Once you've got up to speed, you can trim the sheet on an inch or so and point slightly higher without appreciably losing speed. When you reach this state the inner telltales will continue to flow, but rather than being horizontal they'll creep higher, up to about 45 degrees. You need a good helmsman to keep the boat perfectly in the groove to achieve this. You might also tension the halyard slightly, which narrows the groove (so you need a really good helmsman) but reduces the drag from the sail as you're going faster.

Other more basic things to watch for. Don't overtension the leech line. It just has to be enough to stop the leech flapping. If it's too much, the hook at the leech should be readily noticeable, providing you look carefully.

The other thing is that in light airs, you want more belly in the sail & more twist, so ease the halyard slightly, ease the sheet slightly and move the car aft slightly. You maybe want to be looking at six inches off the spreader in say 5kts of true wind, but all boats vary a little so you'll have to practice to find the optimum for yours.

Very very light airs (if you're racing or really don't want to use the engine) make the sail very tight, so the rolling of the boat in any swell will cause the sails to act like a fan.

Heavy airs, flatten the sail as much as possible. If over powered adding more twist so the top of the sail de-powers and you can reduce the heeling forces a bit.

Of course, you have to be doing similar things to the mainsail too, but there are more control lines for that so it's a bit more complex.

Hope this helps. Enjoy the experimentation on the water.
 
In 40 years of using tell tales I'venever seen an inner one that isn't kicked up about 30 degrees. The more important flow is on the lee side; an inside telltale level means you are too high on the wind. Actually in real light airs you need flat sails because what wind there is will break away from the lee side (the driving side) of the sail. With a main leech tell tales are the best way to go. There's too much mast and crap in the way at the luff which doesn't let the air settle

To help with the original question, if the track cars are located with holes two inches apart, that doesn't give fine enough adjustment.
 
Hi Larry,

I'm basing my opinion on experience of racing and depending upon the conditions and the stages of acceleration after a tack you will get anything between near horizontal flow on the inner tell-tales to them pointing 45 degrees or higher. You deliberately work through the stages to move from emphasising acceleration, then speed, then pointing.

I guess racing is all about pitting your own opinions on sail trim (and much else) against the others so we don't have to agree.

In light airs you need a lot of belly (curvature) to keep the air flow attached. When you switch to flattening the sails is when you have got pretty much no wind.

I agree with you about the effect of only being able to move cars from one hole to another on the track. Without towing cars it is hard to make small enough adjustments.

Cheers,

jcp
 
Nothing advanced at all , if he has 4.5 kts waterspeed from 5kts true wind speed = superb helmsman and trimmers, 4.5 kts water speed and 5kts apparent windspeed = path beaten to door by North sails, Farr boat design, Americas cup et al, but then again he could be using Navman instruments.
Ted
 
Hi Richard,

You should be able to get them flying in 5kts, but you won't get the inner ones pointing up that much. The easy mistake in 5 kts of wind is to over-sheet and close the slot between genny & mainsail too much.
 
Sorry, I named the wrong person. I meant to reply to the comment about the inner telltales, which wasn't the one you made.
 
[ QUOTE ]

I guess racing is all about pitting your own opinions on sail trim (and much else) against the others so we don't have to agree.



[/ QUOTE ]

Discussions like this are very good at spreading knowledge though, and I guess that's what's happening here. The main thing anyone needs to do is to take the opinion / advice offered here, and try it out, but most importantly to develop the "feel" for what works for them and their boat.

A good example is my experience with leech telltales. I never could get on with them until I sailed my Tornado where mainsheet tension/luff tension adjustments were required to get all three going. It was possible to have top and bottom flying with the middle one stalling! Go figure!
 
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