Incidence of Race/Slalom sail bad rotation?

I reckon more or less 50% of all cambered sails (especially 4 cams) that I have ever owned failed to rotate adequately and always required slamming to go over, which soon caused them to self destruct. ..Wondering what experience other fella's have been having "rotation wise" with race/slalom sails? ..The way I figure it is, if it won't rotate cleanly and without slamming it for all your worth, then its not fit for purpose and the manufacturer shouldn't be claiming that its a slalom sail.

It's true that some are better than others, and small adjustments to cams and variations in masts can make a big difference. I find I often have to do some tuning with my larger sails on SDM masts, but have no problems with my current sails.

That said, I have 100% great rotation with all my cammed sails on RDM masts. Can't fault them.

Here is example from a few years ago: 6.2m on RDM mast. Slick as.....

As a weak , lighter , older sailor I want my sails to rotate very easily. I don't even like to have to 'jerk ' them after a gybe.
If they don't rotate easily in no wind on the beach I'm not interested.
I use Severne and I used to have to take spacers out but lately they seem ok out of the bag.
I'm now using RDMs on all of them and this has made them much more user-friendly.
As a lightweight I am probably using the sails below their designed wind range.
E.g - 7m - 12 - 18 kts- patchy wind in chop.

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sailquik said..
It's true that some are better than others, and small adjustments to cams and variations in masts can make a big difference. I find I often have to do some tuning with my larger sails on SDM masts, but have no problems with my current sails.

That said, I have 100% great rotation with all my cammed sails on RDM masts. Can't fault them.

Here is example from a few years ago: 6.2m on RDM mast. Slick as.....

Nice video Sailquik, ..that's a great looking venue, how often is it on like that? ..And I agree your sail's rotation does look pretty slick, I'd be more than happy with that - Actually I've got one sail in my garage that might equal it for similarly nice rotation. A four camber Loft RB 5.0 that I rig on a skinny mast. and that has all around performance that I'm very happy with. ..The troublesome rotation issues that I've got are with two other manufacturers sails that are 7.0 and 6.8 (rig on SDM masts) and which have both virtually self destructed for having to slam them over around gybes and corners.

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decrepit said..
A lot of sails seems to need precise tuning before they rotate well, both downhaul and out haul can affect them.

For Decrepit. I think we've both been windsurfing for a very long time and have probably had similar experiences with difficult camber induced sails. ..You end up arsing about with a massive amount of downhaul tension on, and you're still searching here and there for that finite centimetre at which the damn thing may if you're lucky concede to rotate - And what wind range has it got at the end of it?

It was always a consequence of inadequate design, inadequate materials and inadequate manufacturing quality - All of which come to the fore and cause the most difficulty in four camber sails. And I am saying here that numerous manufacturers to this day still need to raise their ball game in the issue. ..It's one of the things that actively detracts from our favorite sport, which has been diminishing for a long time.

Which may beg the question why do I buy them? ..my answer is simple. Regardless of my old age, lack of bodyweight and lack of physical strength, a properly serviceable four camber race sail with a wide luff tube is "aerodynamically superior" to any other windsurf sail. ..For a given surface area, provides the most bottom end, the best acceleration, and the most opportunity to plane continuously in marginal or gusty conditions. ..I just have to avoid dropping them in deep water, otherwise these are the sails I personally have the most fun with.

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Phromsky said..
I reckon more or less 50% of all cambered sails (especially 4 cams) that I have ever owned failed to rotate adequately and always required slamming to go over, which soon caused them to self destruct. ..Wondering what experience other fella's have been having "rotation wise" with race/slalom sails? ..The way I figure it is, if it won't rotate cleanly and without slamming it for all your worth, then its not fit for purpose and the manufacturer shouldn't be claiming that its a slalom sail.

Check out the Patrik Race+ video showing rotation.

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sheddweller said..

Phromsky said..

a properly serviceable four camber race sail with a wide luff tube is "aerodynamically superior" to any other windsurf sail. ..For a given surface area, provides the most bottom end, the best acceleration, and the most opportunity to plane continuously in marginal or gusty conditions. ..I just have to avoid dropping them in deep water, otherwise these are the sails I personally have the most fun with.

For a given surface area that is probably not true, for a given surface area a narrower sleeve will probably plane earlier and quite possibly accelerate faster( depending on the acceleration mode/dynamics) and in gusty/marginal conditions a narrower sleeve sail set full is more likely to be faster, if more aggressive, to sail with. The advantage of the wider sleeve comes in open water clean, overpowered wind where there is well established flow.
If you are not racing, I can see little point in the wide sleeves.

The more pronounced the curve over the luff - as in, over the outside of the sail from you, when you are sailing - the more lift/suck it creates and hence the more it draws forward. That's what the large cams and wide luff tube in race sails are there for, and I very much doubt there are any non-cambered sails out there that can be set as full in the luff. ..The cams also stabilize the position of the centre of pressure in a race sail in a very beneficial way and to the extent that in many circumstances a race sail is actually substantially easier to sail with than a no cam sail.

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Phromsky said..
.For a given surface area, provides the most bottom end, the best acceleration, and the most opportunity to plane continuously in marginal or gusty conditions. ..I just have to avoid dropping them in deep water, otherwise these are the sails I personally have the most fun with.

While race sails may offer the most consistent planing in gusty conditions, and other advantages, the definitely do not provide the most bottom end for a given sail size. The bottom end advantage goes to freestyle sails, which let me get away with a 5.0 in conditions that call for a 7.0 race sail, when a 5.0 race sail would not plane at all. Freestyle sails require a bit different handling and skills, but you're rewarded with a lot less weight and very easy sail rotations.

Another sail class that easily beats 4-cam slalom sails in most tests are 2-cam freerace sails. You can usually get away going one sail size smaller. The German SURF magazine quite often does direct comparisons of different sail (and board) classes, and it's always the same verdict. It's also my personal experience, even comparing 3-cam to 4-cam sails. One big reason for the difference is the increased amount of loose leech as cams are added.

The fun factor should be what determines the choices, and that depends a lot on conditions, skills, and preferences. I love slalom gear on flat water water, but prefer freeride/freestyle gear in choppy deep water. That said, the latter lacks a bit in the adrenaline department and in the zen department, and the range for a given sail is much lower when foiling, so freeride finning is becoming less and less frequent. In contrast, a few good speed sessions in perfectly flat water are worth driving or flying for 2 days to reach better venues .

Adding or subtracting a 2mm plastic cam spacer from the OD M3's make a Hugh difference to its rotation. I've just added 1 to the battern above and below the boom and it's a pig in lighter winds but awesome when things pick up

For Sailquik and Boardsurfr,

Gentlemen, you are both saying more or less the same thing, so it is easier for me to respond to you both in the same post.
For Sailquik, lets consider how we can test your notion that a wave sail might have more bottom end than a sail with four cambers in a big wide curvy luff tube.

..I'm thinking lets have an imaginary race down your idyllic beach. ..You can bring the best 5.0 wave sail in the world to the party, and I'll bring out the 4 camber LOFT 5.0 that's in my garage. Let's say the wind is square off and around 20 knots. Now we need to establish that all the governing factors are equal. Same boards, fins and bodyweights. And then we rig our sails like for like. So if I see that you are rigging your wave sail with a tight leech then I'm going to rig my 4 cam sail with a tight leech. In fact I often do rig it in this way. The handling and stability still feel great to me, it still rotates as well as I expect. And for all the camber going on in the front of the sail, including at the top cam, the bottom end is impressive.

..I don't copy the way PWA sailors have been rigging their sails in recent years. ..I used to be a pilot and a flying instructor. I've flown more than 80 different aircraft types, ranging from crop-duster's and 1930's vintage biplanes to jets. ..Sails are highly analogous with aircraft wings. "I buy four cambers to try and rig the nearest possible approximation to the leading edge of an aircraft wing" - As seen on something like a basic training aircraft or a crop-duster - The leading edge back to around 30% is where most of the lift (analogous with a sails bottom end and ability to accelerate) is created.

..And at this point I'm bound to comment that numerous windsurf sail manufacturers are overly focused on producing and recommending large amounts of washout in the trailing edge of their sails - Meanwhile in apparent ignorance of the way they are seriously detracting from the performance of their sail's leading edge.

For Boardsurfr, I've also tried to show above that its very difficult indeed to test windsurfing equipment on a level playing field. Regarding windsurf magazine test's. I think the writers very much pander to the manufacturers. Are afraid of upsetting them and not having anything to test next time around. And clearly the manufacturers are trying to sell a lot more freeride sails than race sails. ..But still my comment to you is the same as to Sailquik. If you are going to race me (on a level playing field) with either a no-cam, 2-cam or 3-cam free-race sail, expect me to rig my 4-cam with the same washout in the leech that you've rigged.

Ultimately I am actually employing a similar strategy to you, I have two 2-cam sails (5.8 & 6.8) for sailing in deep and/or rough water

Maybe it's me but never really had an issue with bad rotation in cam sails. I just can't stand the bad stability in some of the no cam/ wave sails. Rig the sail right and the cams will follow. BTW at Corro's most were on 4.5 wave. Me 6.6 Koncept. All had a huge smile

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kato said..
Maybe it's me but never really had an issue with bad rotation in cam sails.

True, but you use them on almost exclusively RDM masts, and you mainly use 'Freerace' cam'd sails, as we both were in the video above.

You are of course entitled to your opinion but if you rig by the numbers on the correct mast then rotation is a easy - yes they pop that's to be expected, if you choose to rig in some manner other than recommended due to your own theory's as to how a sail should be (as opposed to how the manufacturer has designed and made it) then you will have issues like rotation difficulty's or "self destruction".

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boardsurfr said..

Phromsky said..
I'm going to rig my 4 cam sail with a tight leech. In fact I often do rig it in this way.

And there lies the source of your problems. You rig a sail very differently from the way a manufacturer has designed the sail, so you should not be surprised if the cams do not rotate.

Phromsky said..
...which soon caused them to self destruct.

Another consequence of your choice to rig the sails you think is better than what the sail makers recommend. I have owned and used slalom sails from 4 different brands, and not a single one of them ever "self destructed". Some may need a panel repair after landing in the sail in a bad crash, and one or two showed the typical monofilm degradation after using them for about 100 sessions. That's very similar to non-cambered sails (actually, the race sails usually hold up better, since the monofilm wrinkles less when rigging and derigging thanks to the large mast sleeve).

Boardsurfr ..you've added 2 and 2 and made 5 ..deliberately gone to two separate posts by me that refer to different sails and you've extracted my words to suit your argument

..My first comment above is on a 4 cam Loft 5.0 (rigged on a skinny mast) that is very user friendly and that I cannot fault in any respect and that has a lot of rigging latitude, as in anywhere from a tight leech to floppy almost up to the masthead.

..My second comment above refers to a popular brand 4 cam 7.0 rigged on the brands specified top end mast, and that had no rigging latitude at all, because there wasn't any downhaul setting at which it would rotate reliably and even after I removed all the factory installed spacers. ..Slamming the sail over hard eventually causes failure of the batten joints. And that is what I mean by it self-destructing.

I had a previous iteration of the same sail in the same size from two years before and had always been happy with that one. ..Some of them come out of the factory bad. ..It is apparent to me that the factory does not test rig them!

Fortunately the aerodynamicists that worked on the americas cup winning solid wings knew the importance of trailing egde twist to enable a water craft to smash top speed.

And I thought this was the speed forum.
In windsurfing not enough downhaul to match the designed luff curve and twist is so slow.

And how many of these are used under downhauled compared to the manufacturer specs?