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Unregistered 28th November 2009 07:46 AM

Constant Curve Mast

Does anyone know is the shape of the "constant curve" mast of say Northsails same as Gaastra, Severne etc? If i'm not using the top end race sail like warp or code red, but just Ram, S-type, x-type, Overdrive, NCX how would the performance of the sail be if I use the mast of another brand?
(I don't have very deep pockets so i can't be changing mast every time i change a sail, and in the used sail market i can only buy what is available at the time of purchase :-(

joe_windsurfer 28th November 2009 10:26 PM

i am by no means an expert on the subject

however, have had some discussion and done some reading on the web

my understanding is the ideal thing to do is purchase the mast from the same vendor as the sail ie recommended mast

however, there seem to be 2 categories called constant curve and flex top

north sails to my understanding is flex top and NOT constant curve

the constant curves are : MauiSails, Gaastra, Sailworks, Aerotech, Naish, Severne, Autima, Fiberspar and Powerex - some people say MS is a bit softer lower

some flex tops are:NorthSails, NielPryde, Ezzy and Hot Sails Maui

this seems to be one reason why people stick to one brand of sail. i use autima with MS and Gaastra - the rest is how you rig it - downhaul n outhaul

sivagriva 29th November 2009 03:04 AM

Look at this (almost a Bible about masts and....):

PG 30th November 2009 12:49 AM

Hard top:
Maui Sails and Gaastra. Severne RDM are also Hard top (around 10% bend curve), but their SDM masts are closer to the traditional 12% Constant Curve (or average bend).

Flex top: Neil Pryde, and Tushingham SDM masts. Maybe also some of the Hot Sails Maui.

Average, between 12 and 14% include Simmer, Goya, Sailworks, GUN, Aerotech, Powerex, Amex, North Sails, Naish (at least SDM) etc.

As long as you you match mast and sail within the same group of flextop/average/hardtop you should be fine. And masts typically survive many sail generations!

steveC 30th November 2009 04:25 AM

Actually these days all masts are technically constant curve bends, but there are variations on the theme spanning from the flex top to hard top ranges, with the middle range being those most compatible the biggest segment of sail brands. The bend character of the middle range is arguably best represented by the 64/76 curve, and they tend to be manufactured by mast manufacturers that aren't involved in sail design and manufacture. There's some tolerance to these numbers, but the greater the variance leads you to either the flex top or hard top ranges.

So when considering sails to buy, it's the buyer's responsibility to learn more about the recommended bend curve for the different brands. The Peterman listing offers an outstanding resource for judging the bend character of different masts, and it also reveals what's ideal for certain sail brands, especially since many sail brands are having their own masts built to their recommended specifications. So, even though different mast brands can be manufactured by the same company, the character of the brand masts can vary a lot.

Farlo 30th November 2009 06:02 PM

There was a good article in French Planche-Mag last month. Simmer seems to be on the hard(er) top side, then MS/Gaastra/Severne as indicated by PG, then all other brands in the same group, except NP on the flex top side. There is another article this month with different sails tested on right and wrong masts. If you're interested in a specific mast/sail combination, I can try to find out what they say.

Unregistered 1st December 2009 08:38 AM

Farlo, yes it would be great if you could post a summary of the test results.

Isn't it time the sail (& mast) manufacturers show more integrity in their marketing? Only magazines and few people have the kind of resources to conduct such tests. As consumer we deserve accurate product information so that we can make the right decision.

Farlo 1st December 2009 02:35 PM

The rough conclusion is that apart from the extreme hard/flex top brands you can mix masts and sails with moderate impact, but there are exceptions. I will have a look this week-end. You're mostly interested in race/slalom sails, aren't you?

Unregistered 5th December 2009 06:20 AM


I'm just a weekend sailor using slalom board so I prefer a high performance sail but not the top end race sails like Warp & CodeRed.

Farlo 5th December 2009 11:47 PM

Amongst the sails you mentioned, they only tested Severne NCX. Rigging it on a NP X6 mast makes it much less reactive. Adversely NP Hellcat improves in overpowered conditions when rigged on Severne blue line. However switching masts on Stealth and Vapor results in much less perormance. You should not have trouble if you stick to freeride and use a mast in same bend curve group than the recommended one. Ram/Overdrive may be a different story. A friend of mine never managed to get Overdrive's working properly on other brand masts. I'll send you the PM chart of last month if I can find it again.

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