Had a chance to try a new Severne cambered sail today 3 cams in a 7.0, and honestly the draft looked very close to my Aerotech Freespeed 8.0 and the Freespeed performed better. But here is the thing, the Freespeed has about 80% of the draft before a gust hits it, then the gust fills it out and I start foiling, but what happens then? Does the sail reduce the draft back to 80% because the wind pressure is reduced in-flight? If that happens the sail would be more aerodynamic, right? While a cambered sail would keep 100% draft in-flight when it does not need it. I am probably missing something, but like I said the non-cambered 8.0 outperformed the cambered 7.0! And I will bet the Freespeed 8.0 weights about the same as the cambered 7.0 due to the added weight of the cambers.

Your topic should have been more accurately named '8m sail vs 7m sail for foiling'

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John340 said..
Your topic should have been more accurately named '8m sail vs 7m sail for foiling'

Well the idea of using a cambered sail is that it is more efficient in catching the wind, and so in theory you would need a smaller cambered sail versus a non-cambered sail. But the issue of what happens to a non-cambered sail in-flight versus a cambered sail is interesting. Hopefully someone will respond.

The biggest thing I've felt cambered vs. non-cambered, everything else the same, is the cambered stability is noticeably more than even an uncammed freerace. The sizes are different enough that I can't tell you about relative power. I don't think the cambered sails are more powerful on the low end, but much more consistent overall. My 9.5 freeride sail may have similar power to my 9.0HGO, but keep in mind the HGO rigs on a 530 mast and my Cheetah a 490. That extra aspect ratio will give it more lift for the same area. Also, it has a tighter leach than a freeride sail, which should give it more lift too.

From 6kts all the way to gusts of 25kts on a foil on the same 9.0, with the sail getting full outhaul in those gusts and chattering a bit in the upper leach when foiling hard upwind at the high end, I didn't feel it starting to wiggle. It just seems to pull from the exact same center of pressure. The only time it wanders is if the sail gets backwinded from a gust that also has some direction change in the wind.

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aeroegnr said..
The biggest thing I've felt cambered vs. non-cambered, everything else the same, is the cambered stability is noticeably more than even an uncammed freerace. The sizes are different enough that I can't tell you about relative power. I don't think the cambered sails are more powerful on the low end, but much more consistent overall. My 9.5 freeride sail may have similar power to my 9.0HGO, but keep in mind the HGO rigs on a 530 mast and my Cheetah a 490. That extra aspect ratio will give it more lift for the same area. Also, it has a tighter leach than a freeride sail, which should give it more lift too.

From 6kts all the way to gusts of 25kts on a foil on the same 9.0, with the sail getting full outhaul in those gusts and chattering a bit in the upper leach when foiling hard upwind at the high end, I didn't feel it starting to wiggle. It just seems to pull from the exact same center of pressure. The only time it wanders is if the sail gets backwinded from a gust that also has some direction change in the wind.

Aeroegnr, what do you mean by the cambered sail being more stabile? My Freespeeds at min. down haul have a perfectly smooth deep draft from top to bottom with a tight luff sleeve, looked just like the Severne cambered sail except for the battens being alongside the mast instead of locked in the cams.

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Sandman1221 said..


Aeroegnr, what do you mean by the cambered sail being more stabile? My Freespeeds at min. down haul have a perfectly smooth deep draft from top to bottom with a tight luff sleeve, looked just like the Severne cambered sail except for the battens being alongside the mast instead of locked in the cams.

I mean feel and where I feel the pull coming from

okay, thanks
and I am still thinking about how a non-cambered sail could reduce the draft in-flight due to reduced wind pressure and so reduce sail drag as it moves through the air.

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Sandman1221 said..
okay, thanks
and I am still thinking about how a non-cambered sail could reduce the draft in-flight due to reduced wind pressure and so reduce sail drag as it moves through the air.

I've been told this is why you fly with an adjustable outhaul on cambered/race sails.I am still amazed at the immediate feedback in pressure from even 1cm of outhaul adjustment

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aeroegnr said..

Sandman1221 said..
okay, thanks
and I am still thinking about how a non-cambered sail could reduce the draft in-flight due to reduced wind pressure and so reduce sail drag as it moves through the air.

I've been told this is why you fly with an adjustable outhaul on cambered/race sails.I am still amazed at the immediate feedback in pressure from even 1cm of outhaul adjustment

yeah, but try adjusting the out haul in-flight!

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Sandman1221 said..

aeroegnr said..

Sandman1221 said..
okay, thanks
and I am still thinking about how a non-cambered sail could reduce the draft in-flight due to reduced wind pressure and so reduce sail drag as it moves through the air.

I've been told this is why you fly with an adjustable outhaul on cambered/race sails.I am still amazed at the immediate feedback in pressure from even 1cm of outhaul adjustment

yeah, but try adjusting the out haul in-flight!

Yeah you can do it, I've done it. Just have to keep it within easy reach. Same thing with adjustable race harness lines.

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Sandman1221 said..

aeroegnr said..

Sandman1221 said..
okay, thanks
and I am still thinking about how a non-cambered sail could reduce the draft in-flight due to reduced wind pressure and so reduce sail drag as it moves through the air.

I've been told this is why you fly with an adjustable outhaul on cambered/race sails.I am still amazed at the immediate feedback in pressure from even 1cm of outhaul adjustment

yeah, but try adjusting the out haul in-flight!

Just reach back and pull. No different then on a raceboard or slalom. Sailworks style is probably the easiest although I find they get sticky unless rinsed thoroughly if you sail in salt water and are more on/off compared to a proper race setup.

But if you adjust the outhaul you change the center of pressure on the sail and so harness lines will need to be moved on the boom to stay balanced, and that is harder to do than outhaul when in flight. A non-cambered sail just seems a lot easier for my free foiling needs.

Some ideas ... just about any sail works for freefoiling if moderately powered ... and then
Big sails - cams
Big sailors - cams
Racing - cams
Blasting - take your pick
Carving - no cams

As a new foiler, I've just had experience with non cambered(goya fringe 3.7 and 5.3) vs cambered (sailworks flyer 4.5). The cambered sail feels more stable/predictable/controllable in inconsistent winds. Sailing through "finger puffs" and lulls, the constant shape is a lot easier to control in crazy wind. If the winds are crankin stable over 20 knts, the fringe 3.7 works great. The sailworks also feels quite a bit lighter. The fringe seems like a higher quality product in fabrication, but heavier. I suspect it's because its a wave sail that would need to handle some serious abuse. It may just be perception, but the power in the cambered 4.5 "feels" stronger than the 5.3 non cambered sail. Still need a lot more water time to see if that's true.

Cambered sails are more stable because the sail shape is not changing based on wind gusts, and stability is good on foils. What Aeroognr said about using the outhaul is correct too - you can flatten the sail when foiling for less drag and power up when looking for more by letting it off.
The harness lines dont need to change if you have them two hands wide because the draft isnt moving a foot each time you adjust the outhaul.
If you like a non cambered sail better thats your call, but theres a reason lots of people do like them and race foilers use them, so maybe you shouid give them another go some time. :)

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Sandman1221 said..
But if you adjust the outhaul you change the center of pressure on the sail and so harness lines will need to be moved on the boom to stay balanced, and that is harder to do than outhaul when in flight. A non-cambered sail just seems a lot easier for my free foiling needs.

No, I'm pulling 2-3cm of outhaul. That means maybe a 1-1.5 cm change in draft position. How much does the draft on your no-cam move around as it constantly inflates and deflates? Do you adjust your harness lines when the sail goes flat and the battens move forward? I'm guessing not.

And yes, I change outhaul in flight. Like all the time. That's how lightweights like me carry big sails when friends are freefoiling 2-3m smaller.

+1 on the Sailworks outhaul for rec use.

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Sandman1221 said..
But if you adjust the outhaul you change the center of pressure on the sail and so harness lines will need to be moved on the boom to stay balanced, and that is harder to do than outhaul when in flight. A non-cambered sail just seems a lot easier for my free foiling needs.

I rarely adjust my harness lines on my race kit because the center of pressure is pretty consistent across the usable outhaul, at least for the usual wind conditions I sail it in. I may have to adjust for being out in 20kts or so but I don't do that as much because it's rare here and I would like to be on wave board.

Camless are a nice relaxing break from race gear, honestly. I went out yesterday on 6.6 goya mark (camless) on my i76, in really nasty chaotic chop and swells, and could just cruise. Easy setup, easy to uphaul, yada yada. Way easier and less stressful than all out race kit. Only crashed when I ran aground or busted a jibe, even managed to stay going when navigating through a foil mast high boat wake. I "could" have gone out with the Olympic race kit and hauled deep upwind then punished myself with a bunch of likely uphauling for jibe practice but I needed a break for my overcooked tendons.

Everything is a compromise. I think 2 cams with a nonadjustable outhaul may be a good foiling option, at least that is what I'm thinking for around a 7.0 mixed use fin and next foil sail for top speed runs, but I may change my mind and get another 4 cammed race sail. Anything is easier to uphaul than when I have a gnarly crash with the 9.0 when the luff sleeve fills with water. But, that stability is a gamechanger for unpredictable wind when you're hauling deep downwind and pushing it. I don't think I'd want to do top speed runs on a camless sail with the race foil. That may not interest you at all. The stable mast pressure on the foil from a cammed sail makes a big difference downwind. I don't like to sheet out on the race foil unless I'm crapping myself and desperate, as it upsets the foil trim. The slingshot with my mast foot back definitely makes it less sensitive to sail trim, and sheeting out on the slower reacting slingshot foil doesn't catapult me like it used to. That same 6.6 goya on the race gear is definitely more touchy. On the slingshot, it feels more like riding the foil with feathering the sail for more power if I want it. The race foil, even with the long 115+ fuse reacts way quicker to weight/mast foot pressure when downwind, but is far less sensitive to chop than the big i76.

Around 12:30 min into this video was yesterday on the downwind run. I didn't want to go balls out because the rear strap isn't quite where I want it for downwind, and 6.6 was a little much for these conditions with this setup, as I didn't even need to pump. But you can tell I had the sail sheeted out quite a bit and was just adding power every now and then. If easy is what you want, maybe it's just camless?

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If you like a non cambered sail better thats your call, but theres a reason lots of people do like them and race foilers use them, so maybe you shouid give them another go some time. :)

I use a Flyer FR 8.5 (3 cam free race) and 6.7 2 cam for low to mid winds and 4.8 and 3.7 wave sails (no cams, of course) for higher wind. I use adjustable outhaul on all my sails because I sail una very gusty lake (except in summer, when we have steady light winds). I think outhaul for foiling is a must, unless where you sail the wind is steady or the shore is sandy so it is easy to go back to shore to readjust.

BTW, I had the sailworks adjustable outhaul bit a few sessions ago I went with the clamcleat system and I like it better.

From about 2:07 the bloke explains why they use cams in their Sailworks Flyer.

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Panno said..
From about 2:07 the bloke explains why they use cams in their Sailworks Flyer.

That's a good one. That note about stance after 4:00 or so matches my experience. On a freeride sail I'm a lot more defensive than with my much bigger 9.0 usually, especially now that I have really long harness lines on the race sail and try to hike out as much as possible, so I ride them totally differently.

Okay, lots of good information guys, thanks! I have a camcleat outhaul and I find I do not need to adjust it with my Freespeeds unless the wind range jumps 3+ knots. With the Freespeeds my harness line ends are touching, so no gap on the boom, that gives me the ability to sheet out far easily, if I space them farther apart it reduces my sheeting range. So with my harness lines I can feel any change in the pressure point on the sail, and I do not feel a significant difference between unpowered and powered up, so the battens expand outward when the gust hits but that does not change the pressure point like sheeting out does, but then my harness line ends are touching so I can feel 2+ cm change in outhaul. Yeah, been debating race wings, but it is starting to sound like a lot more work for free foiling, especially since I am usually going crosswind, some upwind, but rarely downwind.

Watched the Big Winds video, I think the fact my Freespeeds fill out when the gust hits and get me on the foil, AND then when foiling efficiently the battens likely relax reducing the depth of the sail and that should reduce the drag of the sail making it more efficient for free foiling without having to adjust the outhaul every time I get on the foil.

The other thing I noticed when using the Severne cambered sail sail is it was hard to flip the cams after a tack or jibe when on "the water", now I am wondering how that works out in a foiling jibe.

You pop it just like a slalom sail.
Watch vid of foil racing.

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Sandman1221 said..
The other thing I noticed when using the Severne cambered sail sail is it was hard to flip the cams after a tack or jibe when on "the water", now I am wondering how that works out in a foiling jibe.

Mine works fine. The latest iterations pop pretty much own their own when you sheet in on exit.

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Paducah said..

Sandman1221 said..
The other thing I noticed when using the Severne cambered sail sail is it was hard to flip the cams after a tack or jibe when on "the water", now I am wondering how that works out in a foiling jibe.

Mine works fine. The latest iterations pop pretty much own their own when you sheet in on exit.

Ditto, I've had no rotation issues with my Severne Foil Glide

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John340 said..

Paducah said..

Sandman1221 said..
The other thing I noticed when using the Severne cambered sail sail is it was hard to flip the cams after a tack or jibe when on "the water", now I am wondering how that works out in a foiling jibe.

Mine works fine. The latest iterations pop pretty much own their own when you sheet in on exit.

Ditto, I've had no rotation issues with my Severne Foil Glide

Think that is what I was on 7.0, was a friends and really had to pump to flip it when non planing, did no have enough wind to get up on it though.