mimic hardtop mast using longer cc top?

[manuel]

Does anyone have experience using a longer mast top and shorter bottom to mimic a hardtop mast?

I'm thinking 340b+400t to make a 370, or 370b+430t to make a 400.

My thought is that it'll make the top part of the sail more rigid but may not result in ideal mast curve still.

The idea is being able to get the lower battens farther away from the mast without having such a loose leech.

[jingebritsen]

if that is what melts your butter, go for it.

as stated before, i tend to want sails to be RAF rather than be just fully battened. i like my center of effort low and forward. your efforts to minimize batten tip wear comes at a price of making your sail less stable, thus minimizing sail range. if you would rather rig more often, than sail, that's your choice.

[isobars]

Ever asked yourself why you're the only guy on the planet with these problems?

OTOH, I once had to modify the profile of my Yamaha YZ400 carburetor needle to get it to run right at 1/4 - 1/2 throttle without going too lean at full throttle. But at least my problem was recognized in the dirt bike magazines, and they did not have the solution. Mine worked.



I'd be tempted at this point to just get a different sail. Yours seems to be an anomaly.

[U2U2U2]

[wynsurfer]

I did that with old fiberspar masts. 430 tidalwave base with 460 world cup tip. worked fine, and made the lower battens on a north zeta easier to rotate. The world cup 460 was too stiff in the bottom section.

[swchandler]

As mentioned in the past, I have combined a NL Original bottom with a Sumo top, but both sections are regular 400cm components. This combination gives me a slightly stiffer top. That said, I know that some sailors using NL masts and Gaastra sails are going the route you're thinking about taking to yield a softer bottom and a harder top. From what I understand, the results are quite favorable. Needless to say though, the effort is dependent on using sections of the same mast brand. NL's masts are made to do this, as are other brands like Ezzy that are made by NL.

[manuel]

I just tried rigging a 2010 Manic 5.3 426cm IMCS 19 with an old standard North mast 22 IMCS 190 bottom with a 24 IMCS 230 top. It rigged well with a more constant leech looseness apart from having to use so much force to downhaul!

I was around 427 maybe 428 to clear the lower batten, with decent outhaul the batten above the boom didn't clear the mast, it's probably for two reasons. 1. bottom not quite flex enough and 2. mast being so freaking thick!

Earlier I used the same bottom but with a 210 IMCS 22 top instead and I ran out of extension at 425, but it looked like the top was loosening too early while the battens still had some room to go.

So it definitely looks like it'd help, but would the sail response be as smooth and reliable as it would with a hardtop mast?

EDIT - Here is a hint of an answer: "I tried an older (2006) Naish 100 430, and while the bend was very good, it was too stiff and thus made the sail feel dead. This is how I felt about the Sumo 460 vs. MauI Sails 100 460 (for an Echo 6.9). The Sumo was better than an Ezzy 460, since the bend was a better match, but the MS was livelier than Sumo."

[outhaul]

Isn't the idea of a forum to bounce ideas off others?

[manuel]

Dave replied to me with the bend curve for the 340/400 and 370/430 combos:
64-74, which isn't bad at all. Gaastra's bend characteristics are more around 9 but with 10, it's much closer than 14!

[jingebritsen]

this is not a slam, just another case where those in areas of beautifully strong and consistent winds have the luxury of giving up tons of performance for the sake of convenience.

when fielding advice from those folks, one must take it with a huge dose of salt. that advice may not be applicable to more humble venues. the AWT in hateras shows what happens when skilled sailors on maui specific gear try to sail in onshore conditions. they get worked.