reducing weather helm on stock rigs

Justin_NSA · Jun 25, 2013

Massive weather helm? i haven't experienced it and we sail some high winds in Kansas. Not sure what 'straps' you are referring to. A tight forestay might improve the sail shape some and work against weather helm, but that's speculation on my part. If I have it right, the mailsail creates weatherhelm. Whatever you can do to reduce the power aft of the keel will limit it. By design, boats will naturally round up into the wind.
Maybe someone else has a clearer picture.

crpdm · Jun 25, 2013

Shortening the forestay will rake the mast forward, thus moving the center of effort of the sail relative to the dagger board. I just shortened mine by about 6 inches. Granted it was not original, so who knows where it is relative to "stock". Tightening the backstay bows the middle of the mast forward and flattens the sail, depowering it. It also helps to keep weight forward. When the back of the boat is heavy, the mast tilts back and the dagger board tilts forward, increasing weather helm. This is why when you sail with many people on board the weather helm is worse. I try to convince the kids to go up front.
The S boats don't have as much of a problem, because raising the center board moves its center of effort aft.

Piotr · Jun 25, 2013

You balanced your boat wrong if you have "massive weather helm" while carrying both sails. It happened on my Mac 25, and then I realized that if I simply lower my swing keel, the center of resistance to the sideways force moves forward of the center of sails, thus creating the tendency to turn to. I started locking my keel in the proper position and have NO weather helm at all. NONE whatsoever. Do you have a water balast or a swing keel?

walt · Jun 25, 2013

There is one other thing to consider since it "feels" like massive weather helm.

That is the rudder on that boat not being completely down. If it is only part way down, there is a mechanical leverage that amplifies the force you need on the tiller to run the rudder.

Just something to try but simply putting a good downhaul method to get the rudder completely down and against the stop could significantly reduce the force on the tiller. This won’t help if the boat is actually way out of balance but the rudder not being all the way down with the resulting high tiller force is somewhat common on these boats..

Chris & Lenore · Jun 25, 2013

I second that the rudder must be positively and absolutely "down" while under sail. Even an inch or two back from vertical and the tiller pressure can hit 20 lbs.

This is often mistaken for "excessive weather helm".

I have also tried moving the mast to near vertical and the effect on weather helm is minuscule.

Rudder down and the sail plan balanced and she sails "almost hands off" even close hauled.

Chris

CzechMate · Jun 25, 2013

willsnow said:
I saw on BWYs site that they suggest shortening the forestay as much as the straps allow to reduce our massive weather helm. But I know that tightening the backstay will spill some wind out of the main in heavy winds (maybe even more effective than reefing?) and make it less likely to round up.
These ideas seem contradictory to me. I haven't had the chance to get on the water yet this year and play around with the rig, but that is the plan.
Any suggestions are greatly appreciated

I have used those Delrin shear pins from RudderCraft to hold down the rudder in a positive locked down position.
I have no problem with weather helm on my 26D. My forestay and backstay are trimmed so the mast is vertical
With no sails up, and a very slight backward bend under a strong wind. I think the positive lock of the shear pin
Contributes greatly to minimizing any weather helm. If you don't have a breakable (Delrin) shear pin, try a bolt
Temporarily thru the rudder blade to see how much better it keeps the blade down over tying it down.

centerline · Jun 25, 2013

as other have said, its important that the rudder is fully down and secured tight...

but also, a cause of weather helm is too much sail in the air for the wind your in.... it will cause the boat to heel too far and it will naturally round up to weather....

once the boat heels over, it starts skidding sideways down wind because your centerboard/daggerboard/keel and rudder has lost its grip on the water because its at too much of an angle, and you lose control but still feel the pressure on the rudder.
then, as the sail is laid over so far, with the wind blowing over it, it acts like a single giant fan blade and wants to turn.... as the air spills off of the trailing edge of the "blade", it rotates it forward into the wind.... until the wind has lost its grip on it and lets the ballast regain control and stand the boat upright..... but as soon as the wind grabs the oversized sail again, the cycle starts over....
I see-sawed across the lake like that a few time before i finally understood what was happening to cause my weatherhelm problem.... I realized the problem wasnt the rig, but my sailing skills... imagine that!!!
sometimes a different trim may help, but if the wind is strong, reefing the sails is the correct answer to it.

centerline · Jun 26, 2013

there is some difference in the 26d vs the 25, but the hull shape and standing rigging are the same.... you have a centerboard vs. a weighted keel, but your centerboard has to be lowered fully also for optimum performance on most points of sail....if its not, you can get too much side slip from the hull without as much heeling, causing weather helm. sail trim will be about the same with either boat.
the mast should be raked anywhere from 4 to 6 inches aft on the average to balance the helm, but too much weight in the bow will also cause weather helm. the boat carries the weight well when its forward, and some may say its a bit faster, but the helm is balanced better when the weight is aft....

MrBill_FLL · Jun 26, 2013

there is also a stiffening plate most D owners attached above the rudder to help reduce the play in the tiller. -any metal or wood would work. but most use AL.

http://i64.photobucket.com/albums/h169/ftldiver2/MACGREGOR/P1010016.jpg

Piotr · Jun 26, 2013

willsnow said:
Sorry, I'm on a 26d. I haven't yet tried a pin to hold the rudder down, I do have a down haul on it and its the IdaSailor composite rudder blade. I once forgot to cleat it down and boy, you can really feel it when that rudder swings up even a little bit. And I'm sailing in northern Utah: so reservoirs in the mountains. Air can be really tricky to sail in around here with gusts and changing directions coming down different canyons. Anyway, I have been worried I was going to break my tiller, I've had to fight it so hard sometimes. I think I do have a hefty amount of rake in my mast, so I'll try getting it more vertical. It's good to know you guys have a neutral helm, and its something I can fix

there is definetely something not right if you have so much weatehr helm. Is your centerboard always down and factory original? Also, make sure you have at least 100% jib. other than that, everything that I would suggest was already spoken above. BTW, I overtightened my forestay and have likely 8-inch rake and the effect on the helm is minimal. Check your foils first and make sure they are the correct size and set correctly.

karlos263 · Jun 27, 2013

I also had severe weather helm in stronger winds, couldn't keep her from rounding up. Adjusting the mast rake to 3deg as the manual suggested helped a little but not enough. Last winter I purchased a new rudder/tiller combination from Ruddercraft. The difference is unbelievable, she is now a pleasure to sail with little pressure on the tiller.
Karl