Weather helm at different wind speeds for same sail plan

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SimonFa

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Yesterday I set back from Studland with 2 reefs in. It was a marginal whether I needed them but its always blowy round Durlston and St Alban's heads and I was in no rush and didn't want to have to put them in under pressure.

As expected it blew up a bit and I was glad I had them in. However I started getting serious weather helm at around 17kts AWS and was hanging on at 20kts with full weather helm and traveller all the way out (a long way on this boat). Last time I had 2 reefs in 25kts AWS with traveller out was manageable.

Later on the wind dropped and I shook out the reefs. As I approached Weymouth Bay the wind built and I was sailing comfortably in 16kts, normally when I'm starting to think seriously about a reef and I even managed a couple of 20kt gusts (if I hadn't been so close I would have reefed) with the traveller out, but there was a lot of weather helm.

Apart from the reefs the sail plan was the same with full Genoa, although I have tightened the leech slightly. The Genoa only just overlaps the mast and is cut quite high. Even with 25kts I didn't feel the need to reef it. The main is quite big with a large roach.
 
Weather helm can change with heel, so reefing might reduce weather helm.

If you found a difference compared with two years ago, perhaps one or both of your sails is now baggy?
 
Just sounds like the jib is over sheeted.
If you are not close hauled, a lot of boats will show weather helm under jib only, once the boat is heeled a bit.
Because the jib tracks are inboard, it's always over sheeted lower down to stop the top from flapping.
If easing the jib is not enough to restore control, take a few rolls or change down.
Or steer a lot lower.
 
Agree with bbg and lw. Also, the existence of a big main, traveler, jib-tracks and lot's of roach suggests a modern fractional rig, which should afford you plenty of scope to sort this problem. I'm guessing you set-off around midday with a full spring building up the chuff and running into a decent SW wind while traversing the Durlston and St Alban Head overfalls. So it wasn't calm and therein may lie your problem.

Might I suggest:

1. Welly your rig into the setup you need, assuming your sails are still good that is. Starting with the main. How tight was you main halyard/cunningham? They should have been very tight indeed to pull the centre of effort further forward. Backstay, should also have been cranked on tight to bend the mast and flatten/depower the sail, as should the outhaul, though not too much as some low-down power is good. Turning to the genny: a bolt-tight halyard was also in order (get it off at the end of the day BTW), but might I suggest sliding the cars back a little to open the leech and cracking off the sheets a smidge to create a less stall-prone sail? I'm assuming jib was not too big and it might well have been a tad oversize by the sound of things. This setup will be much better in a bouncy sea.

2. Was this the problem: too much power, boat slowed traversing a wave, then forced off the wind sideways, foils stalled, on your ear; weather helm; PITA? If it was, your new sailplan should have a wider groove and less power, opening the door to a smooth passage with the AWA swinging a little. That is the key. As you approach a wave, push the bow into it, then bear-off a little as you power through the crest. Look at a good racing boat and you'll see the kind of weavy pattern you are looking for. Get the hang of it and this weavy horizontal pattern will deliver a much steadier and more vertical mast; a combination conducive to better speed, comfort and and controlability.

3. Dump the traveler in gusts and if still overpowered, don't be afraid to cool the vang a little to open the main's leech.
​

Hope this helps and enjoy those overfalls :cool:
 
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You do not say if there was a difference is sea state & I do not know the area. Sea state has a big effect. I put first reef in at 17 kts in rougher weather but if the sea is fairly flat I can carry full sail at 22kts. Halyard, outhaul, backstay tension etc ( i have fractional rig) all make a fair difference

My helm was very heavy, but has been reduced by having better sails & rig tension adjustment etc. Once reefed it gets much lighter
 
I'm not sure why people are keen to carry a full genoa with a reefed main. Other than on a very broad reach, when you know you can roll up some genoa when you turn the corner and need to head up, I can't see any merit in it.
Anything above a broad reach, the main will be flatter and better controlled with a better drive:heeling ratio.

A genoa that 'just overlaps the main' probably has the fairleads fairly well forwards? (although the OP says it is cut quite high?) So easing the sheets will increase its fullness a lot.
When not close hauled, it's often best to move the sheet forwards to get the top and bottom sheeted more equally. But that gives a full sail.
IF you can move the sheeting outboard, perhaps with a barber hauler or roving sheet to the toe-rail, that can be very effective.

It is counter-intuitive that the jib can produce weather helm, but that's the way it is.
Sometimes I think the jib is pushing the bow down, moving the effective centre of resistance forwards?
And of course once you are using a lot of rudder that can lift the stern.
 
Thanks, some great and useful replies already. In no particular order:

Sea state was about the same, perhaps flatter yesterday.

I was close hauled at all times.

Halyard was really tight on both occasions, as was the Vang and outhaul. I've had the Genoa down recently but not between sails, so I'll have a go at the halyard.

I don't have a back stay, the spreaders are swept forward. Its a PITA going down wind because the main doesn't go out far before the spreaders destroy the sail shape.

Once again, thanks.

I'll certainly try reefing the Genoa next time this happens, as mentioned this seems counter intuitive as she wasn't on her ears.
Sails are quite old, 12 years.

I'm always looking for a smother passage, hence preferring to reef early and shake out late.
 
Your weather helm does seem to be unusual, if it's bad when you're close-hauled with reefs in the main and without a lot of heel.
Your 12 year old sails can be a factor, since the belly (position of maximum depth) moves aft as they age, which can't be fully compensated for by tightening halyards etc. That effect moves their centre of pressure further aft as well. Maybe this is just the excuse you were looking for to 'invest' in new sails!
I wonder though if there's something else out of kilter. One of my marina mates complained to me once that his boat kept rounding up with uncontrollable weather helm. He knew the cause which was that he'd just had new standing rigging, not fitted correctly so that his mast was raked further aft than should be. Maybe it would be worth looking at your mast rake on your fractional rig?
Can't explain why you would find weather helm suddenly worse two weeks after it being ok, though.
 
SimonFa said:
Halyard was really tight on both occasions, as was the Vang and outhaul. I've had the Genoa down recently but not between sails, so I'll have a go at the halyard.

I don't have a back stay, the spreaders are swept forward. Its a PITA going down wind because the main doesn't go out far before the spreaders destroy the sail shape.
Click to expand...

Oh of course, you drive a Legend with a B&R rig, duh! Okay in that case lw is 100% right to reduce the size of the jib and rely on your infinitely more adjustable main as the primary driver. You might consider an inner blade jib, but this would be difficult without runners.

Why not take a look Selden's mast guide (P54-5) and with the price of snatch blocks the cheap-but-great Antal rings for your outhaulers?

http://www.seldenmast.com/files/1416926327/595-540-E.pdf
http://www.antal.it/eng/55_low_friction_rings_and_dyneema_loops_en
 
If you are close hauled with the traveller all the way out, either the main is going to be back winded by the jib. or you are not really pointing close hauled? in which case the jib is likely stalled?
Do you have tell-tales on the jib?
What happens if you let the boat come up to wind more?


Possibly the main is choking the slot?
Rolling a bit of jib will help the two sails work more independently.
But some genoas lose a bit of shape when rolled, so rolling it just one turn can make things worse.
Assuming the boat is happy with full rig in 10 knots of breeze, in 20 knots apparent, I'd try one reef and say three rolls in the jib and see how that felt.
 
lw395 said:
I'm not sure why people are keen to carry a full genoa with a reefed main. Other than on a very broad reach, when you know you can roll up some genoa when you turn the corner and need to head up, I can't see any merit in it.
Click to expand...

It works for me too - counterintuitively - but only with the genoa de-powered by sheeting it right in. Half rolled in, a roller-furling genny in a strong breeze is baggy in the middle - even with a foam luff strip - and so over-powers the boat, and sheeting it right in flattens it and depowers it. As someone wrote recently on here, it's roller furling not roller reefing! With one or two reefs in the main, and likely the vang on, the main behaves similarly. Even easing the mainsheet, although the main is not in straight airflow with the genoa, the boat achieves hull speed without a dangerous or troubling angle of heel. The heel can create strong weather helm, in a boat with large buttocks.

I'd be interested in others' experiences.
 
Thanks for the links, Dom.

Next time I'm out in strongish winds I'll have a play with rolling in the Genoa and see what happens.

I do have tell tales on the Genoa and they were flying well on both sides, well the lower ones, its always hard to see the upper ones. I did wonder if the leech was a bit tght, but on my own I'm not going down that side of the boat to fiddle about :)

As to sailing, I like to get the boat balanced and flatish, even if de-powered slightly so all I need to do is rest my hand on the helm in preparation for gusts, its far more satisfying than being heeled over and appearing to be going very fast, exciting as that can be at times, hence wanting to understand what happened.

Once again, thanks for all the useful suggestion.
 
SimonFa said:
As to sailing, I like to get the boat balanced and flatish, even if de-powered slightly so all I need to do is rest my hand on the helm in preparation for gusts, its far more satisfying than being heeled over and appearing to be going very fast, exciting as that can be at times, hence wanting to understand what happened.
Click to expand...

Simon, you have made amazing progress in a few short years; it could next AC for you at this rate :D

One thing though, what you describe -- certainly when sort-handed -- is both fast and fun. And much, much faster than the up-on-their-ear brigade!
 
I'm late to the party - as ever - but your basic problem was that you had two reefs in the main, yet still carried full genoa, so your boat was well out of balance. Double the wind speed and you'll experience a quadrupling of the force on the sail, which can be condensed to a point roughly in the middle of the sail, known as the centre of effort.

The centre of effort of the keel is fixed by its position and needs to be matched by the combined centre of effort of both main and headsail, else the boat will want to rotate around the former - and so in your case (i.e. reefing the main brought the centre of effort forward, but but the increased forces on the full heads'l completely overwhelmed things) you experienced extreme weather helm to counteract this. All very inefficient - over-healing, breaking effect of weather helm, etc.

Think in terms of equalising the centre of effort of the main and headsail in any given wind strength. A part-rolled headsail will still work well enough in higher winds, and not fighting the forces in an unbalanced situation means you'll sail faster and more upright.

One reef, fairly calm seas, maybe still carry full genoa, but two reefs definitely roll some away to balance.
 
I have sailed my boat for 25 years and have just realized that the 150% genoa is too big local racing around the cans has shown me that in anything over 17 Kts apparent we struggle to get up wind at all, I found with a couple of rolls in the Genoa we pointed higher and less weather helm, so I have had a new Genoa made 120 % instead, close hauled sheeted hard in and fairlead right forward its a pleasure to steer and by my standards much closer to the wind, however I now have to put on a new track so that I can close the head when reefed even when off the wind as soon as I bear away and ease the sheet the top opens up
Mike
 
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