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I'm always confused on how to balance the helm of a sailboat. Most of the time it appears there is too much weather helm (which actually is designed into a sailboat.
REPLY #1
To counteract weather helm you need to increase "lead". Lead is the distance between the center of effort of the sails and the center of lateral resistance of the keel and wet hull area. The length of this distance, i.e. lead, will either generate weather helm or lee helm.
A simple formula I use is "More lead = more lee" (MOLE?) In other words, increase the lead and the boat will develop more lee helm and weather helm will ease. More lead means less mainsail and more headsail. The inverse is "less lead = less lee" (LESLEE?). Also, a reefed main will cause the boat to heel less and excessive heel contributes to weather helm. Hope this is helpful.
Jack Harding
Flicka Rapport
REPLY #2
Heel Angle and % Lead:
In general, the above statement is correct but another factor must be entered into the equation. When a boat heels, the total center of effort of the sails is offset to leeward and is now outside the hull's lateral plane of resistance. Because the hull is not directly below the center of effort, the boat wants to turn to weather.
To counteract this, designer build-in a certain amount of lead based on experience and information from design books. The principle is to induce a leeward turning force into the boat to counteract the developing weather helm. If this vector is too large, the boat develops lee helm.
Because the mast and rigging are fixed, the % lead built into the boat can not compensate for all conditions, hence the sailor most change the sail configuration to balance the boat, i.e. move the % lead.. In a good boat, this usually means tucking a reef in the main. This moves the center of effort forward, i.e. % lead is increased, and the increasing weather helm is counteracted.
The exception to this rule is when a large genoa is set, such as a 135. In this case, the genoa moves the center of effort back, hence decreases the % lead and increases weather helm as the boat heels. In this case, the headsail area should be reduced before taking a reef in the main.
When the main is reefed, heel angle is reduce, which now moves the center of effort closer to the boat's lateral center. This also helps reduces weather helm. In summary, if the boat develops weather helm, take a reef in the main. If the boat develops lee helm, reduce the area of the headsail or switch over to a staysail. The exception to these general guidelines is when a large headsail is set.
In a well balanced boat which is working to weather, about three degrees of weather helm should be cocked into the tiller and the force on the tiller should be such that only two fingers are required to control the rudder. When sailing downwind, the center of effort of the sails should be moved forward. This helps lead the boat and also prevents it from rounding up. Again, pressure on the rudder should be minimal. Flattening the main will also help reduce weather helm when on a beam to broad reach.
It took us a long time to really understand how to balance African Moon but by trying different sail combinations, "listen" to the boat and sailing in all weather conditions, we now know how to balance her. Learning how to balance a Flicka pays off in the long run - the boat sails faster and is a delight to sail.
Rod Bruckdorfer
Flicka African Moon
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