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Sloop and Jib setting


Spectre

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Last sloop I sailed had a tiny jib sheeted from the front beam via a little "traveller".

My you beaut new 2nd (or 3rd, 4th, 5th) hand boat has a larger jib that is attached to the "hull" about 550mm aft of the rear of the front beam. Is this new larger jib class legal?

Also, I find that I get luff vibration. To get rid of it I have to wind it in to the point that the jib flattens.

However, if I experiment with moving the mount forward by 100-150mm the luff vibration is significantly reduced and the jib maintains a better shape.

The question is:

what is the correct mounting location for the jib sheet block?

Should I be doing something different?

Has the jib reached its use by date?

I guess that ZAX has the answer but all input would help..........

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Ta Jimbo

No leech line. Not hard to do though, I guess.

One gets the impression that the jib block location pulls the jib foot back at the same tension as it pulls down on the leech and this is why the sail flattens.

To apply more tension on the leech than on the bottom of the sail would require the block to be exactly located. I wonder if the racing sloops have a traveller so that the angle can be varied?

I could rivet another saddle to where I think it should be but if wrong the stip that holds the tramp on could end up looking like swiss cheese..

The interesting thing is that the fluttering occured after I reduced the mast rake. This could make sense because it would have the effect of raising the foot. If the foot was lower then more tension would be applied to the leech than the base of the sail. Sounds good in theory.

Maybe I should add more rake before I start drilling holes. I read in another subject that the tip of the mast should be 200mm ahead of the rear beam. Hope they are right.

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Ta so far

Next interesting question relates to this 200mm mast rake.

If I have boat on flat ground it is 150mm. If I level boat so that top of hull is horizontal it is 300mm. So the question is, how is this measured. If in water, I haven't got a bathtub big enough and I sail in waves (all the time) not a millpond.

If I look at the pic on the web home page I am carrying far more mast rake than the boat in the foreground (4001?) and about similar to the one at the other end of the line.

Don't ya just stupid questions like this???

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The larger jibs are used now since they were introduced to the class by Graham Bundock in the early 80s. Many of the sloops use a traveller on each side where your jib is sheeted now.

On ZAX I sheet the jib in closer by having an eyelet in the tramp halfway from the centre of the tramp to the side and just forward of the sidestays. With my current jib I need to move this position aft but have not yet done this. I don't have adjustment apart from on the clewplate of the jib which I set while rigging the boat.

Class rules allow you to sheet the jib whereever you like and use adjustable travellers if desired. A baberhauler is not allowed under the rules.

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You bewdy Zax.

A clew plate seems the go. Cheaper than travellers and offers sail shaping control. My jib doesn't have one - just an eyelet.

Is the clew plate standard on new jibs? How many setting points (holes)? Might think of fitting one if price OK.

Could get new jib but getting attached to the rust marks on old one. Main would have to go first. Dead but won't lay down.

That's a lot of mast rake. Assume you never sail cat rigged. Might give it a try and see what happens. Probably end up in New Zealand. (I tend to furl the jib at over 15 knots - a bit chicken.)

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I got the clew plate fitted to mine as it came just with a single eyelet. It has 5 holes in the one I use.

sometimes I sail cat rigged. Am sailing cat rigged in a regatta this weekend currently in equal second place with Humungas after 4 races. Young Jason K is leading us on a classic mari. I have the mast rake exactly the same for cat or sloop although I do have too much weather helm without the jib. The boat is tuned as a sloop but goes ok as a cat.

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Just back from the Mannering Park Regatta, where Sweet 16 and Pointed Reply mixed it with the Foamies. Seeing Mick becalmed at the first mark of Race 1 while the rest of us sailed away was worth the price of admission.

Back to the jib. On Pointed Reply we have a track. As a starting point set the sheeting position on the jib so that if you extent the line of the jib sheet it should be about one third of the height of the jib luff. The position on the deck will change if you change the rack of the mast and for cut of the sail. A leech cord is good to take out some flutter.

Sheeting the jib on HARD on a work is OK.

Quite a few sloops furl their jibs (while racing) if the breeze is strong, nothing chicken about that. Also the jib tends to backwind the main in strong wind.

But sailing a sloop with crew is the only way to go !!!

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  • 3 months later...

Originally posted by ZAX:

The larger jibs are used now since they were introduced to the class by Graham Bundock in the early 80s. Many of the sloops use a traveller on each side where your jib is sheeted now.

On ZAX I sheet the jib in closer by having an eyelet in the tramp halfway from the centre of the tramp to the side and just forward of the sidestays. With my current jib I need to move this position aft but have not yet done this. I don't have adjustment apart from on the clewplate of the jib which I set while rigging the boat.

Class rules allow you to sheet the jib whereever you like and use adjustable travellers if desired. A baberhauler is not allowed under the rules.

I have been experimenting with this and have tensioned a rope between the deck mounted saddles that the jib blocks were originally attached to. On this rope I have tied on some shackles at varying distances from the edge of the trampoline. On this boat I am finding that if the jib block is attached about 250mm to 300mm from the edge of the trampoline it seem to create the optimum slot with a superior shape of the jib (also no leech vibration) and minimum backwinding of the main.

I am intrigued on where you said the eyelet on your tramp is because from your explanation it would put it under the foot strap.

Can you help me with this John?

Also, I have found that i now have some weather helm when before it was neutral. Can anyone explain to me why this would happen? It makes no sense to me. Maybe I am imagining it.

Damn cold down here at moment. About 15 degrees and 25+ knot soth wester. Went out for a couple of hours and was not fun. maybe it's time for me to hibernate until October.

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You have moved the centre of effort in your sails aft by raking the mast, this has caused the weather helm, the fix is to tuck your rudders under the boat, the bottom front of the rudder should be about 30mm ahead of the line projected through the pintles, fill the pivot hole and re drill, ph 0243591729 if unsure or just want to chat. regards Darcy.

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Originally posted by darcy1945:

You have moved the centre of effort in your sails aft by raking the mast, this has caused the weather helm, the fix is to tuck your rudders under the boat, the bottom front of the rudder should be about 30mm ahead of the line projected through the pintles, fill the pivot hole and re drill, ph 0243591729 if unsure or just want to chat. regards Darcy.

Thanks for your offer - appreciated.

I have tracked it down. Earlier on I replaced the two rope rudder control system with the new type. Avoided the old hifield lever for the same reason 'cause they are not good for off the beach with waves.

Nothing should have changed, or so I thought. But it would appear that the manufacturer supplied pull down rope that was not pre-stretched. Given the conditions the rope stretched slightly pushing the rudders back because of the force of the water (or hitting some weed or jellyfish) plus the shock cord. Because the rope is cleated in, the rudder couldn't go back to where it originally was.

I either wait for it to stretch or replace it with pre-stretch rope.

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If you as darcy suggested run the rope around the end of the casting, get a metal cutting burr that goes in a die grinder and use it in your electric drill. Make the casting where the rope runs all nice and smooth with no sharp bits and a bit of a shallow grove for the rope to slide in. Makes for a better set up than just the rough casting, does'nt cause your rope to fray, which seems to snap there when you don't want it to.

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