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Old 23-02-2015, 06:53   #1
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Weatherhelm Advice, Seeking Balance

I have a 1965 Alberg 35. She has a degree of weather-helm. My sails are tired and my main has no reefing points. Our 150 Genoa blew out last season (our first season with the boat) and we will be sailing this coming season with a new 100% foresail that we found on the boat. I was about to get new sails but had a catastrophic steering failure that needed to be ($$$) addressed. A gentleman from a local sail loft had this to say: Old, blown-out sails can certainly create or add to a weather helm problem. Tuning is a very large factor as well. If helm is a big issue I propose that you shorten your headstay ~ 1.75. while tuning your mast make sure that the leeward upper shroud is not loose while sailing upwind in ~ 12 knots. Those 2 things should greatly help to mitigate any weather helm problem.
I have also read that a degree of weather-helm is desired. The more I read about balance and weather helm the less I understand. And then there is the bowsprit idea... I tend to think redesigning Alberg is not the prudent choice but rather learning to make the most of what her design has to offer and getting to know her better.
Is this what the winter months have to offer for a sailor? Months of obsessing, researching, planning and saving.


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Old 23-02-2015, 07:06   #2
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Re: Weatherhelm Advice, Seeking Balance

DCY, I seem to recall that there is a 'sticky' on the subject. The Alberg 35 should be a very well balanced boat so do not even think about a bow sprit. Some suggestions:
1. Yes, the blown-out sails can make a huge difference. Even if you cannot afford a new main, you should definitely have a couple of reef points for safety if nothing else. Even having one installed will allow you to sail with a single reef in the main, which should make a significant difference.
2. Yes, you can move the Ce of the sailplan forward somewhat by shortening up the forestay.

Brad
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Old 23-02-2015, 07:22   #3
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Re: Weatherhelm Advice, Seeking Balance

I disagree, tune up the backstay. Plumb the mast straight, then sail the boat. If the weather helm still exists, harden up the backstay. This opens the roach of the sail, thus spilling wind. Some weather helm is preferred and is reduced with traveler and mainsheet.
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Old 23-02-2015, 07:55   #4
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Re: Weatherhelm Advice, Seeking Balance

Consider the mast as a pivot point (not stirctly true) for ballance. To be ballanced pressure should be equal both for and aft of the mast, too much pressure aft causes the boat to round up or give weather helm. Your 100% was designed for heavy winds when you would be reefing the main to ballance the sails. So go and have reef points installed in the main to reduce aft pressure and reduce weather helm.

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Old 23-02-2015, 08:23   #5
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Re: Weatherhelm Advice, Seeking Balance

Albergs are great boats and they are all very similar. I had an identical problem on my Alberg designed Cape Dory 26. I fought it for a long time with other stopgap tricks, rig tuning, mast position/sheet adjustments, etc.

Bad main IS the problem. A big bag gives more side force than forward drive. Also, Albergs tend to be tender and like to be reefed early. Too much sail leads to excessive heel and that alone creates weather helm. Do not fool with the rig until you get a decent main. I would predict a better/smaller jib will help some rather than making it worse.
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Old 23-02-2015, 08:49   #6
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Weatherhelm Advice, Seeking Balance

I have a friend with an Alberg 35 with a strong weather helm. He too dreams of adding a bowsprit. But Alberg knew what he was doing. His boats are designed to sail in a wide range of wind conditions by having large enough sail plans for light air and reefing down as wind increases. (I also sailed a Cape Dory for years) Get a new mainsail and a bigger headsail! Then reef early and often.


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Old 23-02-2015, 08:50   #7
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Re: Weatherhelm Advice, Seeking Balance

I also agree that the smaller jib, in the absence of reducing the size of the main (by reefing or otherwise), will make the situation worse. You will move the center of effort further aft, because even though the CE on the jib itself may move very slightly forward, you have much less force acting on the jib. The first thing I do to reduce weather helm (assuming my sails are properly trimmed, something you can't do with a blown sail) is reduce the size of the main without reducing the jib. Once you reduce the size of the jib, the main must be reduced even further. You are between a rock and a hard place...

It is possible that a sailmaker could alter your sail to regain some shape, and at the same time add reef points (I don't know how you can do without them). This would be your cheapest option. I assume you've already done the other trimming tricks available to you (ease traveler, ease mainsheet, tighten outhaul/downhaul/vang).

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Old 23-02-2015, 09:02   #8
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Re: Weatherhelm Advice, Seeking Balance

The first thing I would do, is try sailing it with the new 100% jib. After all, the extra 50% on your 150% jib was aft of the mast.

I tend to find that when it comes to weather helm, precise balance between the jib and main is less important than the condition and size of the sails.

Heel moves the centre of effort aft, and increases weather helm, so sailing with less heel helps. For this you need flatter sails, and/or less area.

For upwind work I much prefer smaller jibs. I now have an 83% for summer when the winds get up, and a 100% for winter. They have no disadvantage at all, versus a genoa, when going upwind, due to their excellent shape. In fact, in 20 kts, the blade outperforms any larger sail going upwind. Downwind is a different matter, a genoa is much better.

Large genoas are for downwind, not up.

A 150% genoa tends to be built of lighter canvas and as soon as the wind gets up, has far too much draft, causing lots of drag, heel, and weather helm. Furling it partially makes it even worse.

To get a better shape in your main you could add a cunningham, and/or get some reef points installed.
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Old 23-02-2015, 09:26   #9
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Re: Weatherhelm Advice, Seeking Balance

Flightplan, if hs main is blown-out, tightenng up on the backstayin order to trim the main will not help. The suggestion that he tighten up on the forestay should, of course, be done in conjuntion with a corresponding letting off on the backstay so as to move the top of the mast foreward while maintaining proper rig tension This will move the Ce of the sailplan slightly foreward and reduce weather helm.

He still, of course, needs to get reef points in his main: as has been pointed out, going to a smaller jib will only increae weather helm and he may need to sail with a reef in the main at all times until he can afford a new mainsail.

Brad
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Old 23-02-2015, 09:36   #10
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Re: Weatherhelm Advice, Seeking Balance

I sail an Alberg 37. It is definitely the large mainsails Carl Alberg designed for these boats. I can manage the tiller up to about 20 knots apparent, but after that a reef is necessary to maintain control. If I am using the Cape Horn wind vane the first reef must go in at 15 knots apparent, with a second reef at 20 knots. It doesn't matter much what size of a jib I am flying, from 100% to 155%, the above holds true. Of course the 155 at 20 knots is a little much.

You need to get at least one reef put in your mainsail.

Roger
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Old 23-02-2015, 09:41   #11
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Re: Weatherhelm Advice, Seeking Balance

[QUOTE=Southern Star;1757018

As has been pointed out, going to a smaller jib will only increae weather helm and he may need to sail with a reef in the main at all times until he can afford a new mainsail.

Brad[/QUOTE]

I pointed out the opposite.
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Old 23-02-2015, 09:46   #12
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Re: Weatherhelm Advice, Seeking Balance

Quote:
Originally Posted by MarkSF View Post
The first thing I would do, is try sailing it with the new 100% jib. After all, the extra 50% on your 150% jib was aft of the mast.

I tend to find that when it comes to weather helm, precise balance between the jib and main is less important than the condition and size of the sails.

Heel moves the centre of effort aft, and increases weather helm, so sailing with less heel helps. For this you need flatter sails, and/or less area.

For upwind work I much prefer smaller jibs. I now have an 83% for summer when the winds get up, and a 100% for winter. They have no disadvantage at all, versus a genoa, when going upwind, due to their excellent shape. In fact, in 20 kts, the blade outperforms any larger sail going upwind. Downwind is a different matter, a genoa is much better.

Large genoas are for downwind, not up.

A 150% genoa tends to be built of lighter canvas and as soon as the wind gets up, has far too much draft, causing lots of drag, heel, and weather helm. Furling it partially makes it even worse.

To get a better shape in your main you could add a cunningham, and/or get some reef points installed.
That's what I'm thinking too. Weather helm is not created by the combined sail effort alone, when heeled a lot some boats get a lot of weather helm also.
It has to do with the combined CE (center of effort ) of the sail area and how far that is from the CLR of the keel shape.
It seems a smaller headsail may move the CE of the sail area forward?
Being overpowered by using the huge 150 genoa may have been your biggest helm problem.
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Old 23-02-2015, 09:49   #13
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Re: Weatherhelm Advice, Seeking Balance

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Originally Posted by Cheechako View Post
That's what I'm thinking too. Weather helm is not created by the combined sail effort alone, when heeled a lot some boats get a lot of weather helm also.
It has to do with the combined CE (center of effort ) of the sail area and how far that is from the CE of the keel shape.
It seems a smaller headsail may move the CE of the sail area forward?
Being overpowered by using the huge 150 genoa may have been your biggest helm problem.
A smaller headsail moves the center of effort of the headsail itself forward, but without reducing the area of the main, the overall CE (with a conventional sailplan) would still move backwards due to the larger contribution by the main, thus increasing weather helm. You can prove this easily on your own boat, reduce the jib without reducing the main, the problem will get worse. Pete
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Old 23-02-2015, 09:53   #14
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Re: Weatherhelm Advice, Seeking Balance

Here's a pic:
With the working jib as shown the combined CE is just at the forward edge of the mast. Now visualize a 150 genoa in the plan. The CE of the Genoa will be considerably aft of the one shown on the jib. Combining the CE's will move the total CE aft of the mast.... creating more weather helm. Right?
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Old 23-02-2015, 09:57   #15
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Re: Weatherhelm Advice, Seeking Balance

Dear sir,
Weather helm is indeed complicated. There are two main causes.
The centre of effort from the sails is not in line with the centre of the centre of effort from the keel (called lateral point). So if there is more effort of the sailarea behind the lateral point the boat than in front of that point (e.g you only carry main and no jib, or the main is trimmed harder than the genoa, the boat will be pushed to windward. The reverse allies when you carry a big genoa or trim the genoa hard on and not the main.
A wellbalanced can be sailed without a rudder playing main and genoa.
Old sails tend to be fuller than new ones and the max depth of it goes to the back of the sails making them less effective and impossible to really depower by more halyard tention and outhaul. Deeper sail...more lift....more power....easier unbalnce of the boat. Using a bowsprit brings the centre of effort of the genoa forward, pushing the bow of the boat to the lee more.
Second cause of weatherhelm has got to do with the shape of the hull. When heeled the underwater ship becomes asymetrical between the windward side and the leeside of it. With bulky boats this effect is bigger than more narrow types.......such as yours..S&S and the likes, .which is why these yachts are more balanced fore and aft causing much better behaviour at sea.......

Hope this helps

Good luck with the trimming of you boat
Greetings from Holland
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