All the problems of weather helm have nothing to do with the rudder / centerboard or sails, although all can affect handling. The mac 26 is a fractional rig, which means the backstay is NOT required for basic rigging except to adjust the bend in the mast for wind conditions to shape the sail (straight for light winds, and bent for heavy winds) The shroud tension is the most important item for proper tuning.
The weather helm occurs because of a bad mast rake. This happens when attempts are made to tighten the shrouds thus pulling the mast aft and giving weather helm. The problem is the stock stay adjusters are likely to leave the shrouds loose, correcting by tightening pulls the mast to an aft rake, thus a weather helm. Most do not re-tune their rig each year so every year, to get the mast up, the forestay is lossened, creating loose shrouds once up then the adjusters are moved - voila - weather helm.
The correct rake is between 2 and 4% - this can be calculated by leveling the boat, using a square and calculating the distance somewhere up the mast between the mast and square for 2-4 %
Another way is simply to loosen the adjusters and tighten the forestay until the weather is gone. This is difficult with the stock adjusters and usually results in some shroud loseness. Replace with turnbuckles.
The wire for sailboats only has a quality stength for about 5 or 6 years, may do not replace but should evry 5 years. Correcting weather would be a good time to add turnbuckles.
A good rigging company is riggingonly.com
I sail in the Canadian North Atlantic, often 20 miles out. Needles to say having the boat reliable and well handling is a must. I have upgraded the wire and to turnbuckles. With correct rake the boat actually can be sailed with one finger on the tiller.
The weather helm occurs because of a bad mast rake. This happens when attempts are made to tighten the shrouds thus pulling the mast aft and giving weather helm. The problem is the stock stay adjusters are likely to leave the shrouds loose, correcting by tightening pulls the mast to an aft rake, thus a weather helm. Most do not re-tune their rig each year so every year, to get the mast up, the forestay is lossened, creating loose shrouds once up then the adjusters are moved - voila - weather helm.
The correct rake is between 2 and 4% - this can be calculated by leveling the boat, using a square and calculating the distance somewhere up the mast between the mast and square for 2-4 %
Another way is simply to loosen the adjusters and tighten the forestay until the weather is gone. This is difficult with the stock adjusters and usually results in some shroud loseness. Replace with turnbuckles.
The wire for sailboats only has a quality stength for about 5 or 6 years, may do not replace but should evry 5 years. Correcting weather would be a good time to add turnbuckles.
A good rigging company is riggingonly.com
I sail in the Canadian North Atlantic, often 20 miles out. Needles to say having the boat reliable and well handling is a must. I have upgraded the wire and to turnbuckles. With correct rake the boat actually can be sailed with one finger on the tiller.