oday 25 original jib style

HukilauMike · Jun 13, 2009

I believe the 23 and 25 were both masthead rigs.

emergpa1 · Jun 15, 2009

Harold said:
was the original 25 oday cb jib an fractional or mast head height style? I have a factory jib that seem's of short luff lenght (about 1 ft.) depending on style or how close the tack was mounted to the deck thanks for the help in advance
harold

Harold,
For us newbies, could you explain what fractional or masthead height is? I think i can guess, but wanted to be sure
keith

HukilauMike · Jun 15, 2009

The easiest way to differentiate between the two is to look see where on the mast the jib halyard exits for its trip to the bow; if the halyard runs all the way to the top of the mast and then down to the bow, it is called a masthead rig (clever, eh?). If the jib comes out of the forward edge of the mast and then goes to the bow, it is called a fractional rig (it only goes a fraction of the way up the mast). Easy as pie. The boat in your avatar is a masthead rig.

Masthead rigs are considered a bit old fashioned at this time. They result in larger headsails and smaller mainsails. The current thinking/fashion is to have a larger main and smaller headsail, as this makes both easier to control.

emergpa1 · Jun 15, 2009

thanks mike

Sunbird22358 · Jun 15, 2009

The 25 was a masthead rig, however that does NOT mean that the jib will always go all the way to the top of the forestay. The "working jib" that was the OEM headsail for the O'DAY 25s with OEM sails actually did not reach the top of the forestay with the tack properly secured to the stem fitting.
Take a look at the picture below, the 160 sqft jib shown would be the "standard" OEM sail.

HukilauMike · Jun 15, 2009

Sunbird: you make a good point; describing a boat as a masthead rig only describes where the halyard exits the mast, it does not describe where the head of the sail is located. As you point out, the head of the jib on the drawing of the Oday 25 you provided is located well below the masthead itself.

Harold, just because its a masthead rig doesn't mean it was designed to have the head of the jib at the masthead. Sunbird's drawing seems to indicate the opposite. That being said, you can adjust the sail to have it fly wherever you like. Many sailors fly the jib as high as they can (using a tail as you have suggested) so that the foot of the sail is clear of the bow pulpit and lifelines and they have a good view off the lee bow. Others like to attach the tack of the sail directly to the headstay fitting so the sail sweeps the deck. I think you have the right idea; try it out in several different configurations and see what works best for you.

RichBone · Jun 15, 2009

Raising the tack of the sail will also change the location of the sheet lead. I haven't set up my rig yet but I think that the jib sheet lead is not on a track.

Sunbird22358 · Jun 16, 2009

RBone, exactly the point that I should have added.
Ideally, the jibsheet should lead aft at an angle perpendicular to the forestay (a line drawn from clew to forestay across the sail, perpendicular to the stay is called the Luff Perpendicular or LP) The length of the LP as a ratio to the length of the J measurement (mast base to tack) will be equal to the % of the jib, so a 100% jib has a LP equal to the J, a 150% jib has a LP that is 1.5 X the J (150%).

Anyway, moving the tack up will require moving the jib lead aft (or up). proper location of the jibsheet block will ensure that both the leach and foot of the jib are tensioned as the sheet is pulled in. And, Yes.....I realize that the drawing that I posted does not seem to show a proper jibsheet lead.

oday 25 original jib style

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