I think this is worth repeating in a topic of its own (thanks Squid Lips)
(copied from www.unifiber.net/masts-selector):
Key questions are:
. why hard versus soft top - that is, is one better for some things than the other?
. how incompatible can you get before its really noticeable (that is, one square or ten out of sync on the unifiber diagram)?
Apologies for the cross posting if you have seen it already.
I recently got the 2012 Naish Forces after years on Ezzy.
I rigged the Forces on the Ezzy masts (about 4 years old) and found that the sails twisted off a lot at the head but the lower battens were quite over-rotated (ie not coming away from the mast enough). This was the case with the 5.3 on a 430 mast, the 4.7 on a 400, and the 4.2 on a 370 (all the recommended mast lengths). Looked pretty ugly and the lower battens were really hard to rotate. I haven't sailed them with these mast combos though.
I rigged the 4.7 and 4.2 on a Naish 100% 400 skinny and it rigged perfectly (as you'd expect) and they sail like a dream.
Then I tried the 5.3 on an Ezzy 400 bottom and 430 top with a bit of extension. That rigged a lot better than the 430 top / bottom. I use this combo on the 5.3 (saves me buying a new Naish 430)
Conclusion: there's definitely a difference, as least in how it rigs. I can't comment on how that might translate to sailing on the water, but my guess would be that the Naishes are designed for a 'hard top' mast, so they'd probably sail better with one.
You have some very innovative ideas Diggers, top marks for lateral thinking, I might try something similar......
From memory your Powerex RDM would sit in about the same spot as the North RDM, but don't quote me on that !!!!!
I had another brand new X6 400 RDM Pryde mast break last weekend and re rigged my 2012 5.4 mFly 2 on a spare 400 RDM Ezzy.
The difference between constant curve and flex top was incredible and instantly noticeable. The sails went from feeling light and perfectly balanced to heavy and back handed to the point of causing spin out problems. I'm guessing there was no where near enough flex at the top which is key to maintaining balance in a 4 batten sail.
IMO, don't under estimate the difference and try and get the mast your sails are designed on.
I always rigged my larger NP Searches (6.2 and 5.7) on the 430 Ezzy and thought they worked really well. But then I am a heavyweight looking for grunt so it all makes sense having a somewhat stiffer top than spec'ed, especially at the lighter wind end of the range.
I have just moved to a quiver of Loft Lips and the Ezzy's work fine with those too - but stands to reason, the mast flex is almost identical going by the above.
I see from another thread that Unifiber have a new 2012 mast curve diagram up.
See www.unifiber.net/masts-selector
Of much interest is the apparent softening in the mast flex of the 'sail du jour' (Severne).
I wonder if this is a reality or just showing up non-systematic error in the Unifiber measuring equipment?
They seem to be refining the chart. Ezzy masts have moved over slightly within the constant curve column.
I was about to ask the following in a new post, then i found this so decided to ask here.
In the buy and sell in Qld Sails, there are a couple of older model gaastra heat waves 4.7 and 5.2, I have a couple of older NP masts a ck35 460 and a c30 430 (was a 460 but cut it down) i think they have constant curve on them somewhere.
would these masts suit the gaastra sails?
thanks
I believe the Heat wave was designed to be rigged on a mammoth tusk. Unfortunately mammoths have since become extinct.
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I think that Unifiber graph is a crock. No way is a Tusshy mast a direct replacement for a Neilpryde mast in a Neilpryde sail..
To the laymen it might seem reasonable, but for the rest of us the fact that the graph suggests these masts are identical says we should take the rest of the 'data' with a pinch of salt.
I guess I have got to chime in and say I was using a Tushingham wave 430 (or something that sounds like that) on a 6m NP V8, and it rigged really well. Having said that, I didn't have a NP 430 to compare it against...
I imagine any manufacturer changes their masts' bend curves a little bit here and there. It might make it impossible to say one mast equals another, even within the same brand.
I don't know who to believe, this chart or the manufacturers own specifications.
For instance, Goya, Hot Sails and Ezzy all spec their masts at a 13 curve, slightly different overall stiffness but all the same 13 curve but on this Unifiber chart they are all different.
Bottom Top
Hot Sails 490 65% 78%
Goya RDM 64% 77%
Ezzy 490 63% 76%
)
"I used to use a Gaastra Remedy that was rigged on a Maui Sails mast, and according to the Unifibre chart it should have rigged 'OK' because the 3 dots are kinda close. WRONG. This was the worst rigged sail in Africa. "
classic!
you may have coined a term here.
Probably still rigged better than the guy with two SDM top halves jammed together
