Hi! I've had 4 mast failures with this sail. North sails platinium 20 cm above boom
Nort sails gold 10 cm under boom
Reptile mamba 80% carbon middle joint
Sailloft 75% carbon middle joint

every mast has the correct bend curve and Imcs number.

I've had great experience with these brands in the past but it seems strange to me that three different brands fail like this. Anyone has experience with this sail?

When do they break?, with that many different brands breaking it sounds like it may be technique related.

As noted above, the North sails from the 'teens, along with NP, were just notorious for breaking masts. The breaks you describe are typical - located around the transition from the relatively soft top to the relatively stout bottom sections, and almost everyone who raced those setups (they were very fast) broke several masts just while sailing normally powered.

You can do a few things to help. First, you'll probably like the sail a lot more for freeriding if you use a slightly softer mast than spec. It'll downhaul easier, pump easier, and it's a pretty flat sail anyhow. Second, never ever leave the sail under tension in the sun for more than a few minutes. Gently let out on downhaul whenever you take a break.

If Awalkspoiled is correct, I would get ride of the sail!, why risk breaking another mast?

I'll second (or third) that.

The problem was fairly common on sizes 7.7 and up. 7.0 and below were generally ok (I rode those a lot and never had a mast failure).

I have F11 ram and everytime I down haul it I cringe, as said above the luff curve and downhaul tenison is massive. Haven't broken north platinum 100% mast as yet. My problem with it is The centre cam refusing to fully rotate after jibing every time. I have a chinook 40% mast that I haven't tried with it yet, I wonder if that would be less likely to break?

WindsurfSystems said..
The breaks you describe are a common symptom of over tightening the boom clamp onto the mast.

Is that really a thing? I've heard it before and it also came up in this thread (www.seabreeze.com.au/forums/Windsurfing/General/Enigma-boom-rope) but I don't believe a mast can break by over tightening the boom clamp if you just use your bare hands to clamp on the boom.

Guy Cribb says (www.guycribb.com/userfiles/documents/downforce.pdf) that it is impossible to crush a mast with a clamp-on boom. My boom is super tight as it should be and never had an issue with good quality masts. I feel that this is more a bad excuse by manufacturers who just blame it as a user error instead of admitting poor quality.

Imax1 said..

ptsf1111 said..

WindsurfSystems said..
The breaks you describe are a common symptom of over tightening the boom clamp onto the mast.

Is that really a thing? I've heard it before and it also came up in this thread (www.seabreeze.com.au/forums/Windsurfing/General/Enigma-boom-rope) but I don't believe a mast can break by over tightening the boom clamp if you just use your bare hands to clamp on the boom.

Guy Cribb says (www.guycribb.com/userfiles/documents/downforce.pdf) that it is impossible to crush a mast with a clamp-on boom. My boom is super tight as it should be and never had an issue with good quality masts. I feel that this is more a bad excuse by manufacturers who just blame it as a user error instead of admitting poor quality.

It was a thing in the olden days with tie on booms . I do up my booms tight and have never broken a mast .

We never know how much tension one puts on their boom clamp do we ? Its also like dropping a 100% carbon mast on concrete, eventually the fibres break. So if all the masts break in the same place changing the boom clamp tension would be my first choice.