O'Day 25 mast rake and front/aft stay tension level
- Thread starter Isla-Mae
- Start date
Trial and error. Try first with the forestay and backstay turnbuckles adjusted the same (same distance from the pin on the bottom up to the upper end of the swage). Then adjust the mast fore and aft to give the proper weather helm. A few years ago someone said the original instructions stated that the turnbuckles should be tightened one turn past hand tight. If I remember correctly. Keep in mind that this was for new fittings. The rig is not a high tension rig so you need to use discretion. Too loose and there will be lots of sag in the forestay giving the headsail too much draft.
Isl-Mae, for racing it is recommended to have about 3-6° of weather helm in the tiller. This is so that the rudder will contribute to the lift of the centerboard. You don't want too much weather helm, otherwise the rudder will create drag and slow the boat down. Since the O'Day 25 is not a racing class, or a one design class, you will not find any tuning guides. However, it is a cruising boat, and as such, does not carry much rig tension as already noted. You'll have to set the rake by trial and error. I recommend sailing in your most common moderate speed wind, and trimming sails on a beat, to determine if you have too much WH, too little, or even lee helm, which is very undesirable. I thought I had mine perfectly balanced, then the following weekend, learned I had lee helm. Back to the dock to loosen forestay and take up others to fix that!
Start with mast completely perpendicular side to side. If you have a non-stretchy main halyard (which you should if you want to race, polyester is NOT low stretch line) then use the halyard side to side pulled down to the chain plates to determine if straight. The uppers will control this. The lower shrouds will be used to hold the mast in column. Sighting up the mast, make sure it's straight, not bowed to one side. Pull any bow out with lowers. Lowers can also reduce mast bend forward to some degree. Some forward bowing in the mast is desirable, but may not easily be attainable in a low tension, cruising rig with a stiff, non-bendy mast. How much pre-bend in a boat that doesn't have racing setup recommendations from a avid racing class would have to rely on discussion with, recommendations from, and possibly hands on assistance from the sailmaker who makes the main. On a boat like an O'Day, with a non-adjustable backstay, I'd play that with backstay adjustment. Again, we are talking about some fiddly racing attributes that an O'Day just plain lacks.
You will probably get more out of the boat from newer sails, as you have discovered from the new genoa. Keeping the bottom smooth is important - no vegetative hair or 20 years of flaking bottom paint. But learning proper sail trim will do even more. Look on this site's chandlery for Don Guillette's Sail Trim book and quick reference cards. This will do more for your sail trim than 90% of sailors! and maybe even more than many racers....
Start with mast completely perpendicular side to side. If you have a non-stretchy main halyard (which you should if you want to race, polyester is NOT low stretch line) then use the halyard side to side pulled down to the chain plates to determine if straight. The uppers will control this. The lower shrouds will be used to hold the mast in column. Sighting up the mast, make sure it's straight, not bowed to one side. Pull any bow out with lowers. Lowers can also reduce mast bend forward to some degree. Some forward bowing in the mast is desirable, but may not easily be attainable in a low tension, cruising rig with a stiff, non-bendy mast. How much pre-bend in a boat that doesn't have racing setup recommendations from a avid racing class would have to rely on discussion with, recommendations from, and possibly hands on assistance from the sailmaker who makes the main. On a boat like an O'Day, with a non-adjustable backstay, I'd play that with backstay adjustment. Again, we are talking about some fiddly racing attributes that an O'Day just plain lacks.
You will probably get more out of the boat from newer sails, as you have discovered from the new genoa. Keeping the bottom smooth is important - no vegetative hair or 20 years of flaking bottom paint. But learning proper sail trim will do even more. Look on this site's chandlery for Don Guillette's Sail Trim book and quick reference cards. This will do more for your sail trim than 90% of sailors! and maybe even more than many racers....