I have a nice set of 2nd hand Severne Blade sails for my bump and jump windsurf sessions.
5.7 - 5.3 - 5.0 - 4.7 - 4.5 - 4.5 - 4.0 - 4.0 from 2021-2023, all in good normal used condition.
But to rigg it well every sail need 2 to 4 cm more downhaul and outhaul then specified.
I use the prescribed Severne red 430 en 400 rdm mast and a 370 blue rdm mast for the smalles sails and a Severne Enigma 140-190 boom and a Severne Cyclops RDM extention, all in good condition.
Before I used my other brands masts and booms, and recently I switched to the Severne Hardware to be sure the dimensions and rigg fitts the sails correct.
All sizes need this extra cm, then the sail still touches the boom al little bit when powered up, I think they rigged well with a nice loose leach like indicated on the Severne Rigg website instruction www.severnesails.com/wp-content/uploads/2019/07/Severne-No-Cam-Rigging-Guide-Blade.pdf.
Is this extra length recognizable by other users?
greetings from Bart from the Netherlands
Yes, I have the same with most of my Blades on Blue Line and Gorilla masts when it comes to downhaul. Outhaul seems fine in my case.
Don't get too obsessed with the numbers, they are just a starting point.
Always found they need more than spec ,. Usually 2cm dowhaul and up to 4cm on some models for outhaul.
I am surprised by the extra amount of downhaul. In regards to outhaul it's basically measured in the middle of the mast cut out and the amount is then sort of an average. I generally have my boom at the top end of the cut out due to being 6'4. I then find at recommended downhaul I have to add 2cm-4cm to the printed measurement. If leave to the leech tight the boom length is about to what's printed on the sail.
That said the Blade has a pretty large range and responds well to different rigging. I would recommend you start with the downhaul. Tight leech for foiling and low end planing super loose leech if you sail crazy overpowered and somewhere in the middle for run of the mill sailing. Then run the boom at a length somewhere between it being super flat and it not folding over the boom arm. Play around a bit and you should find the sweet spot.
The downhaul has always been very accurate in the Blades that I have. I sometimes use a little less in really light winds but never more. To put 2-4cm more on the downhaul is really a lot, and is sounds really odd, to me.
The outhaul is different though as it also depends on the boom height. I often use 2-3cm less than recommended, but I've never used more than the recommended (from what I can remember).
I have 2020-21 and use correct downhaul (pulleys touching on SV ext and masts) and maybeee 1cm more but always 2cm more outhaul
I can't generally have the pulleys touching, either requires more strength than I have or the ropes look a bit too stressed that way with SV extension.
I leave a thumb (say ~1 cm) slack and run the extension 2cm longer. So effectively it's only 1 cm more.
I never use less as the sails don't work well when they are flat imo but for pure DTL wave riding it might be ok. Would use S1 in that case though.
It's also good to keep in mind that no sail is identical, and sometimes the measurements are off due to manufacturing error margins. Also, masts soften over time and sailcloth stretches.
On my blades generally i find the downhall pretty accurate but at 6' 4" i have the boom right at the top of the cutout so need to add at least 2 cm to the recc outhaul, sometimes more.
