Can anyone explain me how must the stripe on top of a sail must be threaded into the lock in a Vario-Top one? I have one that keeps sliding and I think I'm doing it correctly (passing it in a way that at more tension the dented roll bites harder). I've resorted to using an ugly knot. Do they wear off? Or is there a proper no fail way? Thanks!
I think your on to it . The knurled bits are rounding off , and , or , the strap is fluffing and not gripping . I've had slippage on a couple older sails that have been threaded properly . I did the same as you with a knot . I have a similar problem with a harness that gives me the sh.ts , if that makes you feel any better 
Even from new they'd slip a little before grabbing. Always added about 2cm for first rigging and then a knot tied in it no matter how well it seemed to grab. PITA system
Select to expand quoteImax1 said..
I think your on to it . The knurled bits are rounding off , and , or , the strap is fluffing and not gripping . I've had slippage on a couple older sails that have been threaded properly . I did the same as you with a knot . I have a similar problem with a harness that gives me the sh.ts , if that makes you feel any better
Well, sadly, it makes me feel better. I'm a bad windsurfer but no so stupid then. I discovered it the bad way mid session when by chance I looked up and saw 20 cm of mast exposed over there ( realised why the perfectly trimmed sail just moments before was acting like a shaking blanket.)
Select to expand quoteMark _australia said..
Even from new they'd slip a little before grabbing. Always added about 2cm for first rigging and then a knot tied in it no matter how well it seemed to grab. PITA system
Hi Mark, added or subtracted? If you must use 10cm but will slip, you start with 8? If you start with 12 won't it be at 14 when fully tensioned?
Select to expand quoteMark _australia said..
Even from new they'd slip a little before grabbing. Always added about 2cm for first rigging and then a knot tied in it no matter how well it seemed to grab. PITA system
Yup, what Mark said ... and yeah it might slip to the knot eventually (or might not), but as regards the 10cm, 12cm query, TBH, I rig by looking at the leech (for the conditions), lots of downhaul (for my NP sails), so I just adjust the extension to suit. If you lose 2cm off the top you just add 2cm to the bottom (extension), I don't think the mast curve is that sensitive that it will affect the profile. I like to adjust the extension so the sail tack pulls all the way down to the pulley, but that's just me.
k.
Sorry yes I mixed up my terms.
I just mean account for the slip with a new one on first use then tie a knot
Or as jk says just use a little more extension if it has slipped and then the knot stopped it. Obviously do not add 10cmextension hahah
Can you show us what type of vario top you have?
I usually tighten mine really tight by pulling on the strap while pushing down on the cap.
First the roller needs to be slid a bit out of the way so that the strap can be really tight. Then it's pulled tight.
The most it should slide is 2cm. So add 2cm of downhaul. This is why sail rigging visual cues are super important besides any other measuring system!
Select to expand quoteManuel7 said..
Can you show us what type of vario top you have?
I usually tighten mine really tight by pulling on the strap while pushing down on the cap.
First the roller needs to be slid a bit out of the way so that the strap can be really tight. Then it's pulled tight.
The most it should slide is 2cm. So add 2cm of downhaul. This is why sail rigging visual cues are super important besides any other measuring system!
Next time I use that sail I will take a picture. Thanks Manuel!
A sail repair shop can replace the strap and buckle, if they are the problem. But unless you are changing the setting a lot, the strap and buckle should not have much wear, if any. At least that is the case with my Aerotech sails where I set the vario top once, typically, and do not change again.
