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Thought for the Day. Rig setup or what can go wrong will go wrong

Have you ever wondered if your jib leech was too slack and could not find a way to tighten it? I have been through this thought process and a helpful gentleman at West Kirby gave me the last link in the chain of required adjustments to fix the problem.


Possible reasons for slack jib leech


Knackered jib

Too much mast rake

Too much mast bend,(spreaders too for aft, too much back stay, too much mast ram). In stronger winds, set an even bend for the A rig of about 6-10mm.

Too little shroud tension

Too strong elastic on the topping lift pulling the boom up

Your jib boom attachment to the hull fitting maybe forward of designed measurement on the jib boom



Originally I thought you needed lots of prebend in the mast and jib tension to set up lots of jib luff tension and a solid jib leech but this proves not to be the case. I now run with about 12 mm of prebend now, 2 degrees rake on the spreader and a fair amount of shroud tension in a breeze to hold the lower half of the mast in shape. When you ping the shroud it should be middle C or if you have a rig tension meter about 3.5 KG of tension. Of course I set the mast rake with a rig stick and check the shroud tension so it is the same every time. Shrouds and cord do stretch and bottle screws can come loose so be prepared to adjust and check occasionally.


The secret to the jib leech tension is in the bowsie at the top of the jib and control of the mast bend. By tensioning this slightly as the wind builds and allowing the mast to bend 8mm or so, you rake the mast forward slightly. We are only talking a max of a few mm but it does make a difference to the jib leech tension. Experiment and see what happens. There is no reason why you cannot have the perfect set up and if you do struggle getting it right get help from a local club member.

How to achieve a good setup


Here is what I do when I set my boat up and remember I am only a relative beginner but have pulled together everything I have read and been told. It is a bit long winded but I wanted to explain the whole process. The word that keeps going through my head racing IOM's is, precision, in both set up and sailing. It is gradually sinking in to my thick skull. The other phrase that I need to adhere to is stay out of trouble but that is another story

Here is my setup process:


Check rudder is central and fine adjust with transmitter if not.

Put the mast in the boat and fit jib, tighten the backstay to its marks and shrouds to locking nuts. Make sure jib head bowsie is on mark for correct rake

Check mast rake with rig stick and shroud tension with tension meter. Things do stretch.

Check that the mast is in column and not pushed one side or the other. Adjust shroud bottle screws until it is straight.

Check foot depth for main and jib

Check jib and mainsheet positions for upwind and downwind. Upwind, jib just inside the shroud. Main boom 10mm gap from centre of post to side of boom. Downwind, the main boom should just touch the shroud. If things have moved, adjust the end points with the transmitter

Set the mast ram to its mark

With the sails out, set the kicker for the wind on the course. Top batten parallel to boom

Sheet in and you are looking for jib twist of approx 25mm from topping lift. If the leech is showing signs of opening, ie soft, try tightening the jib luff bowsie, make sure the mast is straight fore and aft or has an even curve to match the sail luff curve

Adjust the twist on the main to match the jib.

Put the boat on the water and it should sail itself. The real test of a good set up is when you tack in strong breeze and the boat easily falls away onto the new tack and accelerates. With a slack jib leech it cannot do this. Adjust the back stay if needed to keep the boat on the right course. Heading up, tension backstay, bearing away, ease backstay


It has taken me a while to understand the setup of the rig but now I am there it is easily replicable. There are locking nuts on the shrouds so the bottle screws go to the same place, all the bowsies and sheet hook positions are marked so If I have to throw the boat together quickly, I know I will have a reasonable§ setup.


What can go wrong likely will go wrong


Even when you have the right setup here is a list of things that can go wrong and I have experienced these or seen it at the ranking events. It is by no means complete. Now you can prepare for the unknown.


Bottle screws come loose if you do not check them between race. Apparently this can happen when there is a lot of sail flapping before the start of a race

A shroud breaks - always have a spare to hand especially if you travelled far to a meeting and the length of the replacement measurement and ready to go

I bent a spreader when I tripped by the boat - carry a spare

Jib luff wire snaps. Always carry a spare jib particularly for the A and B rig

Jib downhaul on the boom snaps - This is carelessness as you have let the wear of the cord get out of hand.

You can fall in the water so ideally carry a spare transmitter while the other dries out.

The mainsail shreds. Ideally carry a spare rig if travelling far or the meeting is an important one


I am sure you can add to the list. Whatever your boat setup, enjoy your sailing.






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