Hi,
so I've been windsurfing for 10 years. And my biggest sail used to be a 5.3 (living at the baltic sea in germany).
Now I bought a used Severne Overdrive 7,8 R4 and so far I dont have any experience with such big camber sails.
I read the Severne has a constant curve mast but I only had my gunsails constant curve 460 sdm to try the sail on.
Not being used to camber sails first rigging was a little bit more difficult but having a second look at the instructions and order of rigging it went fine and the cambers went on pretty easy.
Outhaul was also no problem but downhauling needed much more force than with my smaller sails which was expected.
So I have used the Severne two times on the water now. Camber rotation is pretty hard but the second time I used the sail it was a little better probably I because I rigged the sail a little better (used a little more downhaul the second time). I also read on forums that you sometime need to push the camber by foot.. which I also had to do a couple of times. So nothing unusually it seems..
So anyways, rotation a little hard buy expected but what surpised me that the sail was not happy at all with the sail rotation and there was so much force on the middle batten that is crushed the connection of two parts.
Honestly.. looking at how that joint of the two batten parts is constructed it looks very flimsy and easy to damage. There is just a bigger and a smaller batten which are pushed into each other, than at the factory they trilled a little 1mm hole through the two batten pipes and put a little piece of plastic through the two parts which takes all the forces when the batten is under load
So with all the force it just splitt the bigger pipe in part (see the attached video and photo)
So I'm wondering.. am I doing something really wrong rigging the sail which put more force on the batten than there should be or do the old severne battens not last that long. I mean the camber rotate as expected it is not like I have to do a ninja kick to rotate it ;)
Also when the camber rotates sometimes it does it in an S Curve. Meaning the back part of the sail is already on the other side but the front part of the sail near the mast is still on the old side.
Any tipps would be appreciated. Is all the blame on the mast which is not an severne original? I mean the cams go on fine and the rotation is okay too.. or is it just bad luck with the batten, the quality of the joint looks pretty bad and the pieces are not cut straight but at a slight angle and there are caps where it should connect between the smaller and bigger part.
Have a look at my video.. am I doing something wrong with the downhaul and outhaul? Does it look like enough loose leech?
PS: I noticed the broken batten last time on the water. For the video In the garden I rigged it without the the middle camber and batten.
In the video and photo I also show the broken batten and another one which is still intact.
Sail Severne Overdrive 7.8 R4
Luff 482
Boom 208
Mast 460/25
Rigged with 460 Gunsails constant curve mast + 25cm Extension
Boom set to 210
Video here
Can you try rigging it with a friends mast to see if there's a considerable difference? Also Check if the previous owner fitted cam spacers (where the cam slides onto the batten pocket that pokes into the luff). if they're installed you could take them out as this will release cam mast pressure.
Correct downhaul is pretty critical with cambered race sails although from your vid it appears the leach/sail twist is floppy enough - if the extension is set to recommended length then you may need more downhaul* so that pulley block and base is closed up.
Also re: breakages, over tensioned battens may be an issue albeit I had severnes many moons ago and recall one where numerous battens snapped without any undue stress. I'm unsure whether this was just a batch issue as I changed over to Loft Racing Blades probably 7 years ago and they're still going strong. Lots of sailors use Severne though so I suspect any product issues aren't an issue nowadays.
*More downhaul is the equivalent of IT's have you tried turning it off and on again 
I have the overdrive M1 8.6 and use a RRD mast (should have a similar curve as the gun mast you are using). Because the M1 has different graphics it's hard to see whether your downhaul is similar to how much I use, but it looks close enough to have at least good rotation. In theory batten tension shouldn't have an effect on rotation, because the batten pocket is separated from the cam. Only if you have way too much tension on the batten it will have an effect on rotation. Reading your description and the fact that you damaged the batten, my guess is that you seriously over tensioned the batten.
just fix the batten, use less tension and give it another go. The rotation of the overdrive is smooth as can be and it is a great sail. I bought it as my light wind sail because it is so light, but it isn't only very light but also a very stable and fast sail. It's just a great product. (I'm not sponsored, but just a happy customer)
I will check batten tension next time I try the sail, also had a look at what setting it was at.. it was set to middle position like all other battens.
So could turn the batten screw in like 5mm more or 5mm out.
My friends all use smaller sails so unfortunately I got no other mast to try.
The sail came with 1 spacer installed (in each of the 3 cams). After the batten issue I removed all spacers but did not get to try on the water yet.
But again, the rotation did not feel that bad, most of the time I just had to give it a good pump once, only with very little wind I had to give the bottom cam a little foot pressure (the broken one in the one in the middle, it always rotate on its own)
Maybe after all it was just bad luck witht he broken batten and there was not really anything wrong with the setup, after all the sail is already 6 years old (overdrive r4 should be from 2013). I m sure current Severne sails will be even easier to rig and use.
Or should all camber rotate on their own after a jibe with enough wind? Because that did not happen, always had to give it a pump, thought that would be normal with more race oriented camber sails?
edit: also one note regarding the broken batten.. it did not brake to the side because of too much profile in the sail but the smaller piece was pushed inside the bigger piece by about 2cm. So this could also point to too much batten tension? Even at a medium/middle setting? Or just a age related bad luck problem?
I had a Naish Bullit sail that I rigged on the wrong mast.I persevered with it for a long time but it kept breaking battens as the bend curve of the mast didn't suit the sail. Maybe that is what is happening here? For us 'weaker' lightweights rotation is a bigger issue than the guys. Have you removed all the spacers?
I'd be looking at mast compatability first. See if you can borrow a severne mast and see if it's better. The right mast / sail combo makes such a difference!
In the meantime you can try and ease the batten tension on the sticky one. The older Overdrives didn't rotate as well as the newer ones but hopefully you can fiddle with it to get it better.
As a last resort you may be able to sand a bit of the length off the offending camber. The guys can tell you how to do that but I'd be looking at mast compatability first.
After my experience with the Naish I sold it and started buying matched sails and masts..You should be able to find secondhand masts if budget is an issue.
Ps -I'm comparing it to the newer OD's so maybe this doesn't apply but the mast looks a bit stiff to me? Not twisting off a lot..
Ive had that exact sail before, and rotation was not great, even on the spec mast. If everthing is feeling way too tight, check if theres cam spacers on the end of the batten where the cam sits on the batten tip (little brown/grey plastic bit) taking them out will drastically improve rotation. The stainless bit needs to stay on there.
race sails do carry a lot more tension than free ride/wave sails. Its normal to have to give a sudden pull on the boom to make them pop, but the cams should rotate completely without foot assistance.
The easiest solution to the broken batten is a new piece of tube, re pinned into position. If youve got a local sailmaker/repairer, they would be your best bet. You could try fibreglassing it, but keeping it thin enough to fit and strong enough to take the load could be a challenge.
I have a 12mtr and 8.6 R4, both have broken battens at different times, I think the battens used in this model were very light, I have done multiple repairs on both sails and I compared the R4 battens to others and they were about half the thickness.
Severne used to be hard top mast compatible - like Gaastra and Maui Sails used to be
now few sails are hard top - Aventi, Point 7, Vandal
it was confusing enough that some sail makers WERE hard top
now it is important to know the year of the sail ... Maui Sails switched to CC around 2014
sounds like rigging is NOT the issue
either mast compatibility (depending on year of sail) or poor batten quality (other fellow had same issue)
i have had local shop help me with fixing battens in the past
perhaps Severne can ship you new batten ??
i find it difficult to find replacement battens :-(
hope it all works out in the end
Ich wuensche Ihnen VIEL Glueck !! (Umlaut fonctioniert NICHT)
Joachim aus Kanada
I agree - mast compatibility
Wrong curve = too much tension on some battens and not others. You can see it in the leech, its not anywhere near enough floppy....
Bit rough to criticise the batten construction, its a race sail of course they are minimal construction. So they won't like too much tension - and that can be generated by wrong curve. And we do break battens anyway with crashes and stuff......
I'd glue that batten back together with epoxy. Use electrical heatshrink for say 100mm either side to make it neat, then modify cam to suit mast as others suggested.
My 2c is that it does not look like a mast curve issue. You are most likely to have rotation issues if the mast is more flex top than the sail specifies. This leads to over- rotation of the cams as the lower mast is not bending enough, the upper leech is very floppy and the lower leach tight. I am not seeing this in the video, the leach is loose right down. Could be a mast diameter issue but does not appear to be a drastically wrong mast curve.
Disclaimer is that the video is not conclusive.
My 2 cents worth .
In the last 5 years I've only used cammed sails .
The reason is because I'm heavy and non cammed sails move around too much, cammed sails like being overpowered and hold their shape which suits me fine . I'll put up with the extra weight .
So I live with cams.
What I have noticed with cam rotation ease is , it's a balance . You want forced shape . It's a fine line . You want to flip over and with a sturdy yank , want a positive flip to the other side .
wing shape .
This doesn't always happen .
Incorret mast sail match is the first to blame . As it happens it's not always the case .
If for any reason the cams don't flip easily enough or all the way , its because there is too much tension between cam and mast . The physical batten curve shape or batten preload won't change this problem .
On sails with spacers ( North for instance ) , it's got to do with the cam to mast pressure that varies. Less pressure = easier flip , but your losing that solid foil shape .
So , I believe .....,
No matter what combo your using, if your cams don't flip easily enough , there is too much pressure between cam and mast .
Fix ?
Reduce spacers, if u have them , to reduce distance between batten pocket to cam distance , which will reduce cam to mast distance . or , if perfect mast sail combo still doesn't work , ( sadly surgery is needed ).
Nobody wants that .
Ive had to do this on one of my favourite sail quiver . Only on the large one. It was a design fault
It happens.
So , if you have tried everything and it still won't flip easily enough you need to mechanically modify cam to mast pressure.
Before losing all hope and needing surgery , Mabee a little more downhaul ?
,
Select to expand quoteMark _australia said..
Bit rough to criticise the batten construction, its a race sail of course they are minimal construction. So they won't like too much tension - and that can be generated by wrong curve. And we do break battens anyway with crashes and stuff......
It's an observation not an opinion, they are about half the thickness of RSX battens. I have broken plenty of battens in many sails but the R4 sails I have seem to have extra fragile battens. Haven't had anywhere near the same issues in R3 or R5 or R6 sails.
With the sail pictured below in the 2017 formula nationals we were fixing battens as best we could in the hotel room every night so that we could race the next day. You can see the tape on the 3rd batten sleeve where I had to cut the broken one out. It kept breaking everyday and in the end the batten was full of hard spots. and the tube had to be replaced with a new one
Since replacing the tube the below sail has not had issues breaking battens, I still have it and it still goes great it just had really fragile battens.
Yeah , ****y battens are a thing.
I broke a second batten down , in the middle . No crash , first time out . Only noticed it rolling it up.
How is that possible ?
Select to expand quoteMark _australia said..
I agree - mast compatibility
Wrong curve = too much tension on some battens and not others. You can see it in the leech, its not anywhere near enough floppy....
Bit rough to criticise the batten construction, its a race sail of course they are minimal construction. So they won't like too much tension - and that can be generated by wrong curve. And we do break battens anyway with crashes and stuff......
I'd glue that batten back together with epoxy. Use electrical heatshrink for say 100mm either side to make it neat, then modify cam to suit mast as others suggested.
the 2011 Severne was hard top
the 2012 was constant curve
2013 also constant curve
the Overdrive R4 is production year 2013
and my Gunsails mast is from 2018 and also constant curve, not a perfect fit but should be pretty close?
Poehaaa said he used a RRD mast with his severne, that should be even worse but works fine on his sail.
you can check bend curve test of all mast from third party mast maker here and select all the different years at the top
www.unifiber.net/masts-selector-2011-v1
maybe I just need to put some more downhaul next time to get more floppy leech like you said as you can see in the video I still got 5cm left at the bottom when the extension is set acording to instructions. Thats why I made the video for you guys to comment because I dont have experience with those big sails :)
Regarding the batten construction, in theory it might be a good design but the quality of assembly is not nice on this particular sail, or maybe just this batten. Again look at the photo. On the small batten part there is this bigger part put on to act as a stopper where the bigger pipe should push against, but there was like 0,5mm gap between, of course over time the load will be only on those small 1mm pins which split the batten pipe in half and the bigger pipe is pushed over the smaller part like it happened here.
When I checked the other battens on this sail the big pipe pushes nicely on the stopper part like it should be so it spreads the load and not all the load is on the little pins. Only the middle one had this little cap. I mean if those little pins would be enought to hold together the batten than they would not have added the stopper part on the smaller pipe. Also the pipes of the batten where it broke where not cut at a 90? angle so I think it is fair to say the quality was not so great atleast on this sail
So next time will try even more downhaul, less batten tension with a little bit of wringles.
But I still think could be just bad luck with the batten, because again, other people on the forum seem to report much worse rotation. And a few people now already commented on quite a few broken batten with older severne sails.
And if a RRD mast works on Severne Overdrive than my Gunsails should too. Because the RRD has quite a lot more flex top which should make the bottom part even tighter with worse rotation.
And I will try to put together the batten again. Maybe so that it pushes on this bigger stopper part and drill a new 1mm hole through both parts and put a new pin in. Or I cut of the part where it split, drill new holes etc. and add some cm at the end from another batten.
Maybe I try building a completely new and a bit more flexible batten from other old batten parts too just for testing.
"What does not fit is made to fit"
Select to expand quotecammd said..Mark _australia said..
Bit rough to criticise the batten construction, its a race sail of course they are minimal construction. So they won't like too much tension - and that can be generated by wrong curve. And we do break battens anyway with crashes and stuff......
It's an observation not an opinion, they are about half the thickness of RSX battens. I have broken plenty of battens in many sails but the R4 sails I have seem to have extra fragile battens. Haven't had anywhere near the same issues in R3 or R5 or R6 sails.
With the sail pictured below in the 2017 formula nationals we were fixing battens as best we could in the hotel room every night so that we could race the next day. You can see the tape on the 3rd batten sleeve where I had to cut the broken one out. It kept breaking everyday and in the end the batten was full of hard spots. and the tube had to be replaced with a new one
Since replacing the tube the below sail has not had issues breaking battens, I still have it and it still goes great it just had really fragile battens.
thanks for the feedback
so that would also point to just bad luck with the batten. I mean maybe this was just a one time thing with my sail, the other battens look fine when I checked them after the first one was damaged.
When youve got your batten fixed, a test you can try to see if things are rotating correctly:
rig the sail, flip it over, get a friend to hold/put a foot on the mast tip to hold it against the ground then push down on the mast base to the ground. All the cams and battens should pop across by themselves, try it a few times to set them in position. If they don't, or are reluctant to, then you need to remove spacers first. If that doesn't work, then review the mast situation.
Otherwise you're just stabbing in the dark and you might spend money you don't need to spend.
Select to expand quoteSubsonic said..
When youve got your batten fixed, a test you can try to see if things are rotating correctly:
rig the sail, flip it over, get a friend to hold/put a foot on the mast tip to hold it against the ground then push down on the mast base to the ground. All the cams and battens should pop across by themselves, try it a few times to set them in position. If they don't, or are reluctant to, then you need to remove spacers first. If that doesn't work, then review the mast situation.
Otherwise you're just stabbing in the dark and you might spend money you don't need to spend.
okay, have not heard of that test before.. will try that next time
^^^
This Is the best dry method , only I do it in reverse . I get a mate to stand on the mast base and push the tip down . Same thing .
It seems violent and goes with a bang , but it happens every time you turn around .
Its a good indicator of what it should do without wind to force it into shape.
If it flips perfect using this method , it will be perfect on the water .
If it passes the dry test and you have problems flipping it on the water , it just needs a stronger yank on the boom .
Removed the 1 spacer that was still on the cams (it is only around 2mm but makes a big differents). Now shifting works great.
So no problem with the gunsails mast on this older Severne overdrive.
Also replaced the broken batten with a new one I made from old parts. They both weight 260gram. But the new one is just a little bit more flexible, which seem to work great in low wind sitution like it was today, profile looks the same as before. The new batten joint I made is two batten pipes and a 10cm long hollow batten pipe as a sleeve.. so the two pipes can simply push against each other, certainly much more robust than the old one... did not have to glue anything just put the pipe over the joint, fix the sleeve in position with tape.. done 
Will try it again in more stronger winds if that works good too I might just keep this new batten and take some more time to repair the original one.
The little bit more flexible batten might also help with the shifting of the sail.
