Altering mast rake. Advice needed

paulsmith

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I have recently launched my Westerly Griffon after after buying it at the end of last season.All is well except the mast appears to lean slightly forward (I thought it must be me, but today someone said 'Your mast leans forward') so it looks like it will have to be dealt with.The previous owner had just had the standing rigging replaced and set up by a pro rigging company so before the mast was taken down each bottle screw was carefully marked so I know its in the exact same place as when I took over the boat (when I viewed the boat it was in a marina so it wasn't possible to stand back and view the rig from a distance). So can I just adjust the forestay and tighten the backstays and leave the shrouds as they are.I don't want to alter more than I have to. Or will I need to set up the whole rig to change the mast angle a couple of degrees. I don't want to get out of my depth and end up with the mast all over the place. The other method is to leave well alone as since launching a week or so ago I've sailed it on three occasions each time in strong wind conditions and it sails beautifully with no weather or lee helm problems. I think I've just answered my question!
any thoughts?
Paul
 

Talbot

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If you do change it, make sure you can remember how to get back to the same as you have now. If you are not happy with the rake, slacken off the shrouds and then slacken of as much of the headstay as you feel comfortable with, check to see if mast has tipped back to about the right angle, tighten backstay, check again, when happy tighten up the shrouds again.
 

CLP

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If it was me I'd adjust the rake. Yachts look wierd with forward rake and they don't go upwind very well either. You should have a few degrees aft rake, probably about 4 to 6 inches on a Griffon. You will get a little weather helm by increasing the rake. Personally I think this helps to give the boat some "feel". A boat with lee helm (achieved by having forward rake) is aweful to sail and directionally unstable, you don't know if it will bare away uncontollably if you let go of the helm, which could be disastrous. I hope this helps.
CLP
 

snowleopard

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a boat shoud have a little weather helm. it helps the boat luff up if you let go the helm in a panic. it also gives you lift to windward from the rudder. it sounds as though the previous owner tuned out the weather helm.
 

Mudplugger

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It is possible, that if your mast is leaning forward at rest, by the time you & your crew are in the cockpit, it will be vertical, if she sails without lee helm and a slight touch of weather helm in moderate conditions you are not too far away. You could try taking up on the backstay and if this results in a a couple of inches of prebend ( for & aft) you should be able to go to windward.......HTH...if it feels right, it probably is!
 

William_H

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One other aspect is that if you have the boat on a swing mooring with no one on board anda heavy chain on the bow then the boat is going to sit bow down and so look like it has negative rake. I say leave it. There is no reason to believe it will sail better to windward with rake aft except via a little weather helm. it always seems to me that weather helm is a result of too much heel in strong winds and not nearly as much from mast position as people say.
regards olewiill
 

bugs

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If its too far forward you will have lee helm and will almost need to push helm to keep it on course. The centre of effort in the mainsail should be behind the centre of gravity in the keel. Raking the mast aft achieves this. There should be enough rake to give about 5 degrees of rudder angle (assuming its a tiller). It is difficult to sail well without a little weather helm. Too much rake and you will have a wake coming off the rudder.
Does the mast step have adjustment. The shrounds may have been tightened to the previous settings but it the base of the mast is in a different position the angle may be different.
Also, while the shrouds may be tighetened to the previous marks the tension may be different. Forestay may be tighter and shrouds looser.
You could use a rig tension meter to find out.
If there is anyone near you that races their boat they will be well used to adjusting the rig.
 

Sheerline

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You need to tune the boat for a little weather helm (say 3-5 degrees of rudder close-hauled in 10 knots) not for the "look" of the mast. On rare occasions, older boats sometimes have non-standard keels, masts, booms etc which can change the centre of effort and require different "odd-looking" rake.

Making the shrouds the identical length to the old stuff isn't the go. The old wire will have stretched - so the new shrouds etc will need to be slightly shorter when new.

By the way, it's not the centre of gravity of the keel, it's the centre of lateral resistance.

My boat has a non standard keel and rig. We got the keel placement slightly wrong - too much weather helm - so I have a slight amount of forward rake to bring the effort forward, mast step is forward and I've also put the forestay forward to assist. (And it goes upwind like a champion!)
 
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