Using IMCS 19 on a IMCS 24 sail ?

[B737]

I located a 2001 northwave surflite 4.7 sail that calls for a IMCS of 24 (based on what I could find on it over the net). Will this sail 'work' on a mast that's correct length but is an IMCS of 19?

The mast in question is a 2007 NP Wave X6 400Cm.

I'm not a performance junky, I just want something to sail when it's too much for my 5.7 expression. I keep getting blown out!

Thanks guys,
Kevin

[swchandler]

I think the reference to IMCS 24 is incorrect. What is most likely being highlighted is a MCS 24. You should be fine with an IMCS 19 mast as far as overall stiffness, but the bend curve might be a different issue, as NP's masts are on the flextop side of the constant curve scale.

[B737]

You may be right...it's not very clear. Looking at the same model 2009 specs only say "mast 400/24"

I did not know there was a IMCS and an MCS stiffness rating

[swchandler]

I might be showing my ignorance here, but as I recollect, MCS ratings were based on the standard 15'/460cm mast. Later, IMCS ratings were developed and introduced to reflect the relative difference in overall mast softness of different mast lengths. Small sails require softer masts than much larger sails, particularly those larger than 8.5. So, under the IMCS rating system, shorter softer masts tend to be rated in the mid to high teens, whereas longer masts incrementally increase stiffness, or the IMCS number, up from there dependent on their overall length.

[U2U2U2]

when I had Northwaves, 2001 & 02 so the same age as you are looking at, they sold me Powerex skinny. Powerex is considered a constant curve
about 65% 77% subtract the 2 get 12, that equals constant curve. BTW the mast worked fine with those .

from what I see on my chart the X6 is 60.8% 77.8 % = 17, and this translates into a FlexTop. Quite a bit more flexy overall than the middle of the road Powerex.

http://www.peterman.dk/windsurf-mast-article-gb01.htm

this will provide hours of frustation.

FWIW the NP on a sail that old should be okey dokey.

[hammerton]

The mast will be fine, in fact it will be great! Don't get caught up in all the bull!

Just go sailing and enjoy.

[B737]

[U2U2U2]

regards sails I would take Hammers advise, Formula 1 take mine

[U2U2U2]

73
the % numbers I quote are the mast deflection when a weight is hung from the 1/2 way point, the numbers are the % deflection from 1/4 and 3/4 point, which indicate more so than the IMCS numbers which all end up the same , per each size mast.

so we have masts that range from very stiff top, to very soft/flex top, with some companies using adjectives of their own making, to comform to certain standards, so to increase sells .

sorry to drag up this load of crap, its my headache # 101

so sail and smile

[B737]

Ahhh ok... thanks for the explanation U2, that makes sense.

Thanks for the input here guys, I'm glad it'll rig

[jarecki]

Rigging it will tell you a lot. I had a Powerex skinny as some have mentioned, though don't know if it was the correct stiffness / curve for my 02 Surflites (I think 99 % identical to 01's). It rigged horriby, and the sail sailed horribly. It was difficult to downhaul. Switching to NoLimitz fixed everything. A grey NoLimitz, not a silver one. Softer. I don't know about the X6, but I once tried to rig a skinny Tidal Wave, and it rigged like the Powerex. On the water, with the Powerex, the sail felt flat & gutless until it completely loaded up...almost an elastic thing, with a "snap" to the power once it got loaded. Switching to the NoLimitz, the power comes on early, smoothly, and progressively. I think the MCS/IMCS numbers did not tell the story. If I recall, the 400 Powerex was a 19 IMCS, and the NoLimitz is an 18. Doesn't sound like much, but was a huge difference for some reason....definitely the Powerex appeared too stiff. That said, the Powerex was bought from Sailworks, who probably sold me a mast too stiff for the Northwave on purpose.