Just a tad overpowered today . Downhauled till my sail and mastbase pulley's were touching with the mastbase set to manufacturers settings but my leech still seemed to be tighter than everyone elses.

Is this just an old vs new sail design factor as mine is about 6yro? If not, then how much further can I dare to extend the mast base? my luff tube has already endured multiple repairs and snapping the mast while rigging would be suicidally embarrassing not to mention painful on the wallet.

Oh, to have wind, let alone be overpowered ! you lucky buggers!

The numbers on your sail are only a guide, if you need more downhaul then make your extension one notch longer.

Sails stretch, not all 430's are actually 430 long, masts differ in how much and in what shape they bend, different extensions have the pulleys in different spots, the list goes on.

If you're not using a crank then you'd be pretty unlucky to snap a mast just by downhauling.

I know that the leech on my new sails are far floppier with lots of downhaul than my old sails. My old ones dont seem to loosen off at all, just flattens the whole sail more. The new ones definitely looser and far better. My newish 5.7 far more manageable than my much older 5.0.

What I don't understand with downhaul is that it always seems to be more, the better.

So regardless of who/how a sail is done, the next guy always says it's missing pull there. And so on. Basically the right downhaul seems to be that of the muscliest guy on the beach these days.

Just an observation, I do my own anyways.

It doesn't matter how you rig it, as long as you rig it right.

Hi, Knigit,

I use the correct NP masts on all my gear and my old "Search's" definitely have less floppy leeches than my "Alpha's", so your observation is correct.

Providing that you have the correct sail/mast match and that you have ascertained that the mast length is correct (as per Nebbian), the power of the sail can then be adjusted by outhaul (in general, a sail can be adjusted for power up to about 0.8 to
1 squ.m smaller than its actual size, but gybing with a too-large sail in overpowered conditions can be difficult).

Hope this helps,

Brad1: it's forecast to be up to 35 kts here today. Suggest moving to Melbourne!

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pierrec45 said...

What I don't understand with downhaul is that it always seems to be more, the better.

So regardless of who/how a sail is done, the next guy always says it's missing pull there. And so on. Basically the right downhaul seems to be that of the muscliest guy on the beach these days.

Just an observation, I do my own anyways.

That's one of the design pionts I like about Ezzy-Sails. David takes the guess work away re:min/max downhaul and outhaul rigging. Would be great if other sail makers incorporated this feature in their sails.

Do sails stretch? I've got a couple of sails that rig around 40-60mm longer than they should...also on the outhaul. I've tried to rig them to manuf specis, but they're way too flat, or balooned (not enough out). I now tend to rig them to what looks/feels right, takes a little longer, but it's worth it when you get it just right for the conditions.

Another thing, after exploding a sail whilst trying to add a bit more downhaul (manually - geez I'm huge!, using a 2 pulley & cleat extension, not 3), I wondered if you can physically apply too much downhaul, or did I just have a dodgy sail? I was told that I could apply as much as I physically could if conditions warranted it...

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Sailhack said...

Do sails stretch? I've got a couple of sails that rig around 40-60mm longer than they should...also on the outhaul. I've tried to rig them to manuf specis, but they're way too flat, or balooned (not enough out). I now tend to rig them to what looks/feels right, takes a little longer, but it's worth it when you get it just right for the conditions.

Another thing, after exploding a sail whilst trying to add a bit more downhaul (manually - geez I'm huge!, using a 2 pulley & cleat extension, not 3), I wondered if you can physically apply too much downhaul, or did I just have a dodgy sail? I was told that I could apply as much as I physically could if conditions warranted it...

Sails do stretch, especially during the first half-dozen riggings as the sticking takes up the slack. Once the stiching is bedded in, since monofilm doesn't stretch too much, so you are usually stretching the stitching.

Sail exploding? Depends on what you mean by exploding... the pulleys on a two-pulley system can put too much pressure on an individual pully, causing them to fail.

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pierrec45 said...
What I don't understand with downhaul is that it always seems to be more, the better.

Thats not strictly correct... most sails can be over-downhauled. The "more is better" rule came into play because most people didn't / don't put enough downhaul on in the first place (and often apply too much outhaul too).

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pierrec45 said...
Basically the right downhaul seems to be that of the muscliest guy on the beach these days.

They can slog all they want.

My rule of thumb:

Wavesails: pull as much downhaul as you physically can, and that will be a little bit too much.

Race sails: pull as much downhaul as you physically can, and that will be a not quite enough.

If the sail is made right and stretched in then the numbers should be pretty exact.

I've noticed with a few modern sails of differing brands that the downhaul range is very small (2cm) and the remainder of the tuning is done with outhaul. If you don't look at downhaul specs then you probably wont be getting the most out of your sail, because little changes mean more than many sailors can pick up. Mauisails have recently introduced a load cell into their testing which has shown how critical small adjustments are-

how much DH you use is personal and relates to your mast/sail relationship. inour case, say on a tr-5 7.6 as an average size, we find that when you hit 130-40kg you are at a minimum setting that you might be able to sail with, and at 190-200kg you are getting into the over tensioned zone. in this particular case, the adjustment required to go from 130-200kg is about 15mm. when you are nearing the recommended DH, mm's change tension by 20-30kg. so you can see that fine tuning and paying attention to settings is valuable.

However this doesn't mean you can't not use hardly any downhaul or overdownhaul. Not enough downhaul doesn't lock the draft in place so your harness lines will feel too far forward. I'm not going to say they don't drive or stop your board from planing or pull your arms from sockets as i've seen it work quite well (and tried it once or twice to good effect ), modern sails twist enough and masts soft enough for this to happen. The sail just wont feel ideal (though anything feels ok if you do it enough) and you could get thrown easier, its also a good way to snap battens in cammed sails.

Overdownhauling- i've never seen a mast snap from downhaul load alone. I have seen sails pull apart at the seams at the tack and in the luff, and i've seen some sails with worn monofilm burst every panel up the sail. Common belief is that sails feel "wooden" if you overdownhaul the sail. As you downhaul more the draft is moved down in the sail and locked in. If the draft is low enough it wont be balancing everything correctly so it may lock the board onto the water etc, though this may change with another 5 knots of wind. Pro's may look like they use stacks of downhaul but they also change battens around, have many fins to try and years of collective experience to get everything tuned with each change.

Personally I used to regularly overdownhaul but found outhaul then becomes very sensitive, always kept neutral-negative to let some shape form in the sail otherwise sail became way too twitchy. Never had a problem with board sticking as I was using board and sail in too much wind. Never had a problem with damage to sails either, the sail I regularly used to overdownhaul is still in use by a friend and is still going strong after 13 years. Some sails don't seem to mind being overdownhauled, some feel terrible. It's a trial and error thing.

If the leech is still tight it may just be because of the build of the sail. "Power" sails will use a tighter leech, often they will still have alot of twist built into the sail. So don't go on the amount of folded material when comparing to other sails. It is the excessivly folded sails that will be damaged when overdownhauled as this flaps away when going upwind.

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mkseven said...

I have seen sails pull apart at the seams at the tack and in the luff,

This is what mine did...near new sail, 'BANG!' and that was the end of the excitement for me, as it was my smallest sail, and I was looking at making sure I pulled it down pretty well (due to 30kt+ winds)...

...all good now, sail repaired and I had my first go on it today since the repair!

Btw, good detailed report there mkseven!

There are 2 manufacturers that I know of which have had a problem with failure inside luff sleeves irrespective of max downhaul (max downhaul just accelerates the failure) in recent years, I know that one of them has fixed the problem for the 2010 sails by changing luff panel material to xply and taping it also.

www.peterman.dk/windsurf-NP-RS-series-780gb.htm

At the bottom of the page is a picture of wrinkles that will be seen in the luff if there is any failure along the luff panel (from overdownhaul or material fault). If you see these have a look and get the sail to a sailmaker otherwise the next downhaul will be the last

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pierrec45 said...

What I don't understand with downhaul is that it always seems to be more, the better.

So regardless of who/how a sail is done, the next guy always says it's missing pull there. And so on. Basically the right downhaul seems to be that of the muscliest guy on the beach these days.

Just an observation, I do my own anyways.

You should check your settings with a tape measure when you first rig your sails i found that i was rigging my 6.2 6cm more than max setting because the extension measurements were out, the sail had alot of control but lacked drive.

you don't need to crank the hell out of the downhaul, bigger sails do need more effort to downhaul them, sails tend to feel gutless and twitchy with to much, when you hold it up into the wind you intend to use it in the head should still have a bit of tension in it not just flopping around.. the point of the loose leach is for the wind to flow from the sail to make it more efficent.. a flat sail also loses the entry angle of the leading edge, or angle of attack if you like, if you notice the modern race sails which get the most RnD they are getting deaper in the foil and getting better to use and faster.. instead of cranking on the downhaul just rig a size smaller and rig it correctly..

Not all sails have the same leach twist it's just the way they where designed..

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Mark _australia said...

My rule of thumb:

Wavesails: pull as much downhaul as you physically can, and that will be a little bit too much.

Race sails: pull as much downhaul as you physically can, and that will be a not quite enough.

damn good observation