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View Full Version : Severne Reflex II - who has experience with it ?


BelSkorpio
31st December 2010, 06:15 PM
Hi,

I have been doing some reading about the Severne Reflex II system.
http://www.severneracing.com/reflex_system.php

It looks like a nice concept, those reflex batten tensioners.

Myself, I have never used the Severne sails and have no experience at all.
I also don't know of another sail brand that has this reflex system. Perhaps there are, I don't know.

Does anyone have real experience with it ?

marekk
8th January 2011, 02:36 AM
Hi BelSkorpio,

Nobody answered for your question, thus maybe my answer will be helpful for you. I never ride on this sail, but last season I talked with Steve Allen and Wojtek Brzozowski about Reflex. They claim it is working perfect - you can adjust performance of sail for different winds and how it should reacting for gusts. Sailing overpowered is becoming safer and more effective.

But in my opinion (and many other nonprofessional windsurfers):
1. Sailor need experience with this adjustment to achieve effect of improved ride
2. You must be very experienced sailor If you need to have significant benefit from this.

After that talk I felt myself interested, but I'm not convinced that it is solution for me.

I hope my answer is helpful a little...

BelSkorpio
8th January 2011, 05:30 AM
Hi Marek,

Thanks for the response. At least someone who is reacting :)

I think, Severne has made a very nice video of how the reflex batten tensioners are supposed to work:
http://www.severneracing.com/product_video.php
Nice how they show the bend curve of the battens when they are tensioned not from the end (leech) but closer from the middle.
Theoretically, I think they are right. It should move the power of the sail even more forward. How much more, I don't know, because the cambers are doing this anyway.

That's why I asked people with real practical experience.

Steve Allen was involved in the development, so it's normal that he promotes the system.

I'm rather convinced that it will help the performance of a sail. It will create a profile that gets closer to the wing of an airplane.

BUT, theory needs to be proved by practice !

Erik Loots
10th January 2011, 06:12 PM
In practice you can see during sailing the leech react active, but with great stability in gusts, the frontend of the bottom battens is extreme stable. This is what I like about the reflex system.

I would not say it is harder to rig and trim than other race/ slalomsails. Maybe a small transition in way to rig/trim (depends mainly where you come from).

Romas
14th January 2011, 04:19 PM
<Nice how they show the bend curve of the battens when they are tensioned not from the end (leech) but closer from the middle.

It look like commercial trick. If batten place in pocket and stretch it, picture will be not same like in video. Then extra increasing batten tension in regular sail it not make profile deep, contrary to this that make S-shaped profile.
Sorry for my English

BelSkorpio
15th January 2011, 12:01 AM
Do you mean a S-profile between mast & reflex batten tensioner ?

Or S-profile between mast and leech because this obviously is the purpose.

Remi
15th January 2011, 01:11 PM
Hi All

Just come from practice with Wojtek on Reflex II 12 on Formula and found the sail very nice, really ligth in hands and very effective to get planning and very good acceleration and top end speed. But the most surprise is the cam rotation, I never see before a cam rotation like this, super easy. Save a lot of time for taking and jibe.
All the best

pfaffi
18th January 2011, 02:47 PM
Hi BelScorpio!
I like the bigger range of the Reflex sails but you have to use a outhaul trim system!
If you come to an overpowered stage just pull the outhaul and you will recognize that the sail will be a bit fronthanded and controllable instead become backhanded!!
:-))))
pfaffi

ps.: cant wait for the Reflex II :-((( (should arrive in 2 weeks)

Farlo
18th January 2011, 08:08 PM
Just asking but what is the benefit of Reflex and the like systems (NP dynamic compact clew...) if you still need to adjust outhaul when sailing? I would imagine that these sails never get backhanded because of their S-shape.

Erik Loots
18th January 2011, 08:40 PM
Farlo, good question ;). My biggest reflex is 7.0, and I do often focus on GPS speed. I would never put tension on outhaul. Recommended - 1 till -4cm, negative outhaul feels for me more stable. I guess it activates the S-shape better..

pfaffi
18th January 2011, 09:02 PM
Hi Guys!
True but....
If you like to ad +/- 5knts wind range take an adjustable outhaul!!
Thats answer enoubgh or?!
pfaffi
(sorry to tell but 7,0 we use in competition > 30knts and I would like to see one of you with -4cm in these conditions)

Erik Loots
18th January 2011, 10:03 PM
@pfaffi

> 30knts and I would like to see one of you with -4cm in these conditions

Yeah, difference in discipline, I would do full downwind with 30kn wind in my 7.0 with -4cm ;). There is downwind much less apparent windspeed in the sail with good speed, but I agree if slalom or match racing (competition) its better to pull the outhaul to boost speed.

I do have an adjustable outhaul on all booms even for the 5.6/5.1, because I can't go all day downwind and end again at the place I started :).

Farlo
19th January 2011, 12:09 AM
OK my question was not clear. I guess many sails will get extra wind range with an adjustable outhaul (though +/- 5 knts seem huge). One would expect the Reflex system to adjust automatically to wind variations, short and long wavelengths. Downwind/upwind is another story but the sail should never become backhanded, by design. Otherwise why is it superior to traditional cutaways?

pfaffi
19th January 2011, 02:46 PM
not to be to technical but:
Deep Downwind like Erik told is a lower apparent wind and you can go with deep profile. Upwind (go back after downwind) is a higher apparent wind and less twist in apparent wind direction. Therefore upwind a deep profile is contra productive and will force you to open very much your boom/sail and go slowly and less angel. You will win with outhaul for all circumstances. But it is also true that the Reflex System will lock the force in a wide outhaul range but don't over-stress it.

BelSkorpio
27th January 2011, 12:08 AM
Hi guys,

if you want to read a little bit more theory about how a sail (or a wing for that matter) is supposed to work:
http://www.sailtheory.com/sail.html

It shows with pictures, why you need a big belly in front of your sail while reaching, even more curve while going downwind and why you need a flatter profile when pointing.

I found it very interesting.

Farlo
27th January 2011, 03:38 PM
Hi BelSkorpio, It is a nice article indeed. A flat profile has better lift/drag ratio and works with smaller AoA, to some extend. So I fully understand the use of adjustable outhaul for that purpose. My question was about wind strength, not direction. But I can understand that even the best sail in the world may become backhanded and require some trimming. BTW aren't all sails like that?

BelSkorpio
27th January 2011, 05:59 PM
Hi Farlo,

Yes I understand what you're saying.
Regardless of the wind direction and corresponding outhaul adjustments, the sail should handle a wide wind force range.
That was also the reason why I brought up the topic.

If we discuss only 1 wind direction, say reaching,I think that the reflex system with the reflex batten tensioners could improve 2 important issues:
- give more twist and better release of overpowered windpressure by means of an increased S-profile
- tunnel more power to the front of the sail, resulting in less backhand power, more comfortable handling and better performance


So with the reflex batten tensioners, they improve two issues at the same time.

Not that bad, I think.

I haven't seen this yet with the other sail brands.
The other sail brands all tension their battens from the leech, and rely on the "dynamic or integrated" compact clew (NP terminology, let's just call it reduced boom length) to create more twist and S-Profile.
To improve the forward tunneling of the wind power, they only rely on the cambers.

Severne Reflex has of course also the cambers and reduced boom length, but add the reflex batten tensioner technology as a surplus.


Again, I have no experience with these sails, but would like to try them out.

Farlo
28th January 2011, 02:30 PM
Hi BelSkorpio,

Recently I've heard a few guys saying that batten tension is not that important (seen that written on this forum as well). It shall be strong enough to remove wrinkles and that's it. In my shop they even advise to keep them slightly loose. Therefore I wonder if the position of the tensioner makes a big difference, moreover close to the boom. OK maybe the Reflex is designed to work with big tension but I guess the foot of the batten is so stiff that most of the S-shape is given by the cutaway. Does anyone know what the rigging instructions tell about battens?

BelSkorpio
28th January 2011, 06:06 PM
Tension is not that import. Just remove the wrinkles. True. I even wrote that myself somewhere on this forum, I think.
But you always create tension when you bend battens, else they would remain straight in their natural form. And this tension will now be applied to an end-point further away from the leech, more to the front of the sail, resulting in a curvature a little bit more to the front of the sail. Again, every camber has the same goal, but the reflex tensioner will help with this, I think.
And then last but not least, there will be no tension at all in the batten at the end between reflex tensioner and leech, allowing better twist and more S-shape according to me. I would like to see those reflex tensioners more in detail to see how easily they allow the negative bending during overpowered conditions.

Farlo
31st January 2011, 04:16 PM
Hi BelSkorpio, IMHO the batten tension has little effect on bend curve. Most of it comes from the sail shape and wind pressure, I believe. But it brings some tension in the sail body which may affect responsiveness. Just read in test reports that NP integrated clew also require outhaul adjustments for max wind range. Nothing magic, seemingly...

Farlo
19th December 2011, 10:24 PM
Hi all, have you seen the outhaul position mid way to the cutaway on the Reflex III? This topic has been discussed on other forums but I 'm still looking for an explanation. Severne is not advertising that much on this third clew eye, which looks very bizarre. What are the benefits of such a large cutaway + reflex system if you end up with longer boom / tighter leech again? (With all respect to BD who never won a single PWA event before being on Starboard/Severne, oops it's AA... sorry ;-).

Remi
20th December 2011, 05:08 AM
Hi Farlo,

When you have light winds this increase the power, the reason why for example the RaceBoard sails have always longuer boom. Then when the wind is not any more light or light gusty you go for the normal position and the third one is for small riders or the ones who like to have their boom lower at the clue.

Hope this help

All the best

Farlo
20th December 2011, 04:50 PM
Hi Remi, thank you for the answer. This sounds logical but I'm still confused. I though the whole story about cutaway/s-shape/reflex battens... was to cope with strong and light wind with the same trim. Of course Severne sails are doing well in competition but it seems a lot of technology and extra stuff not to solve any problem. For instance a true innovation would be to get rid of adjustable outhaul. This been said, I'd rather try one to make up my mind

Remi
20th December 2011, 04:53 PM
Hi Farlo,

It's a race machine so multiple set up to get the best performances at any time.

By doing this you wil feel more power on the back hand and it's working great.

One trim can't work at hi level for all condition, so it's a very good option, try it and you will feel it imediately.

Have fun

Farlo
21st December 2011, 01:58 PM
OK Remi, I'll try if I have a chance. But if you need to change clew according to conditions it's not so great revolution compared to other sails. Rather put a mobile connection that would slide along the boom batten. Just my 50 cents.

fataux
22nd December 2011, 05:48 AM
As for no pros, imho, trimming is one joy part of windsurfing. For a revolution point of view on the other hand i couldn't say much. But everybody need some marketing either this way or that way :D (may be it is a revolution and not a marketing mambo jambo that i don't know, may be i have a chance to try next season)

Farlo
22nd December 2011, 02:58 PM
Hi Fataux, my point is that the third clew eye seems to have similar effects than adjustable outhaul, but of course you can't change it when sailing so I wonder where the miracle is. On the other hand, if changing clew position has significant impacts on sail's behaviour (s-shape to c-shape) then you could design an adjustable clew eye mobile along the protruding part of the boom batten. Not sure it would replace adjustable outhaul, though. Racers may want both.