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  1. #1
    Senior Member ross24's Avatar
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    Losing rig towards the back of the board whilst planing

    Hi All,

    I went out on my futura 122 (40cm fin) and 7m north natural sail on friday evening and had a good session. Was reasonably powered up, but the wind was a bit gusty, so occasionally it took a bit of pumping/ bearing away to get going.

    Sometimes whilst blasting in the straps, I would find that the rig would fall towards the back of the board, and I would have to almost hold it upright to stop it falling backwards. It would be quite awkward, uncomfortable, and tiring. I was usually sailing just upwind of a beam reach at the time. I've been trying to work why it was doing this?

    I thought that it may have been that I was sailing through a lull, but when I think back I was reasonably powered at the time. The other option could be harness line position - but with north sails there is an indicator for where to put them (but to be honest the lines never quite felt in the sweet spot). I only the had the sail on the minimum downhaul setting as I used too short an extension by mistake when I rigged it, so I wonder if that may have been a factor? The clew on the sail is quite low - it only has one eyelet unlike other sails, plus the boom cutout is quite low. I'm 6'2", so wondered if it might have been that?

    I've had this other times with larger sails as well (8m and 9m on 145 and 170 litre boards).

    Any ideas what's causing this?
    thanks
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    '17: 9

  2. #2
    Super Moderator na-omi's Avatar
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    Hi Ross, no idea really, but my gut reaction is the same as yours: sail set gutless, boom too low and lines too far forward... sure there'll be some expert opinions in a mo.

    I find on my sails I have to move the lines on a particular sail depending on how much down- and outhaul I've got on... my sails have a huge range, so if I don't move the lines at the extreme ends the kit becomes very badly behaved. I've learned the hard way to always try the line positions *before* I launch by sheeting the sail in on the beach on both tacks (fitted to the board), and getting my hands as close together as possible either side of the lines to make sure they're in the right place for the actual wind and set. If I don't it can all go horribly wrong very quickly, which is a bit punishing on some beaches where getting in and out is a challenge in itself. Well worth doing IMHO... I've long since given up with rules of thumb / bits of elastic / markings for harness line position: fine for a ball-park position, but no substitute for empirical testing!

  3. #3
    Senior Member ross24's Avatar
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    Hi na-omi, thanks for the comments. Yeah harness line positioning is not something I've yet mastered! Am getting a bit better at trying to set them before I go out on the water. But usually I'm in such a rush to get out there I forget to do it!

    In this case the sail has got a handy marker on it for where they are supposed to go, so I can't have been that far wrong (?), but still they never quite felt in the sweet spot whilst I was sailing.

    Point taken about how the set of the sail - down and outhaul can mean the lines have to be adjusted - I hadn't thought of that.

    I was wondering if anyone had had a similar thing happen?
    cheers
    '16: 16
    '17: 9

  4. #4
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    Lack of downhaul or possibly downhaul and outhaul was your problem I think. The only reason why a sail would want to fall back is that the effort in the sail has moved right back and is pushing the clew down. This is most likely to occur as you head up and of course if you lean the mast back it will make that worse. Re your harness line position I would use the marking on the sail as a starter guide only. It is relatively easy to set your lines in the beach start position if you have not checked them when you rigged up. Present the sail ready for a beach start, bring your hands closer together until they are only about 2 fists apart. If you are balancing the rig OK to beachstart your hand positions are now where your harness lines should be. You may need to tweek that a little once on the water.
    ps there is no need to have the velcro fasteners on the lines tight around the boom.....keep them just loose enough so you can move them easilly....that also helps to stop them destroying the grip!

  5. #5
    Senior Member stupendousman's Avatar
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    I can remember this happening to me once or twice and its an uncomfortable feeling. But it was years ago and I cant remember what sail it was with. I dont know the answer, but logic would suggest that the weight of the rig is greater than the pull generated from the wind, making it want to fall backwards. Seeing as the sail pulls from the centre of effort, which will vary greatly depending on the set of the sail, then I would agree that its worth trying to vary the set, in order to move the CofE. Possibly try moving the boom and or masttrack position to put the sail more upright? I'm guessing really.

    Or..only ever go out in 3.7 winds. problem solved.

  6. #6
    Just wondering. Where have you positioned the mast foot in the track?

    And what mast do you use? (i.e. what does it say on the label?)
    Now back in the UK.

  7. #7
    Senior Member ross24's Avatar
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    Hi Mikerb and Stupendous, thanks for the comments. yeah it was quite a frustrating feeling. It's actually pleasing to hear that someone else has also experienced it. As I've had it a number of times with a couple of different sails.

    I only had downhaul to the minimum setting, to the mark on the sail, as I used too short an extension when I rigged it. I gave a few centimetres of positive outhaul if I remember rightly - will try max downhaul and play around with the outhaul, and see if that makes a difference next time it happens. I still haven't got my head around the whole centre of effort thing, and how it moves with flexible booms, different down/outhaul settings and so on! I suppose that'll come with experience.

    That sounds like a good method for harness line placement mikerb - will try that out, thanks.

    Hi Basher - I was using an older SDM tushingham mast IMCS 25, 45% carbon. I had the mast foot in the middle of the track, between the visual guide marks. Quite a number of my sails and masts don't match so perhaps that's contributing to my sail problems.
    '16: 16
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