Sail recommends longer mast than the luff

U2U2U2 · Posted: Mon Oct 13, 2014 1:36 pm Post subject:

what Dan said I feel is correct.

for the sail in question, the use of a 430 or 460 is not going to create much difference, assuming that the mast bend curve is in the ball park on either

keycocker · Joined: 10 Jul 2005 Posts: 3598

the stiffness number can be confusing.
MCS is real stiffness numbers.
IMCS is Indexed Mast Check System. The theory behind it is that a 430/21 is the same stiffness as the 460/25. The different number is caused by indexing the mast stiffness number for different lengths.

Without the index applied, the two masts above would both have a MCS number of 25.

Why do this? Take a stick that is a little bendy and saw it in half. You will find the two short pieces much harder to bend, if at all.
The halves and the whole would still have exactly the same stiffness, of course. Cutting it would not change the stiffness, just the length.
in the older MCS system the two pieces would have the same stiffness number as the larger piece , but be harder to bend.
The index MCS adjusts the stiffness number according to length.

PeconicPuffin · Joined: 07 Jun 2004 Posts: 1830

It sounds like you are a beginner or early intermediate sailor. Is that accurate? If so the shop was probably doing you a favor by setting you up with a slightly bendier mast than you'd want if you regularly sail full powered, ripping in the footstraps.

I recommend setting your base extension to zero, shortening the top as much as possible, rigging the sail, and posting a photo of it here. There's a decent chance you will benefit from some tuning tips, and if the mast is overly soft that should be apparent.

U2U2U2 · Posted: Tue Oct 14, 2014 9:32 am Post subject:

bred2shred · Joined: 02 May 2000 Posts: 989 Location: Jersey Shore

This sail was likely a part of a beginner board/rig package. HiFly builds boards, they don't build sails, but they do sell beginner packages. HiFly has their own mast base system and typically the beginner packages come with a fixed length base that as no extension. Therefore, the only adjustment with HiFly's standard package is by adjusting the length of the head cap. So the standard mast with the HiFly package is a 460 mast and you just adjust the head cap down to the right length. The dealer likely sold you an upgraded mast (higher carbon content than the HiFly package mast which would have been 0% carbon and a shorter 430cm mast) to cut down on weight and make the rig easier to handle. We used to do that all the time.

You should run the sail with the head cap tightened up all the way so no mast sticks out of the top of the sail and then adjust your mast base length so you can get the correct downhaul setting.

sm

U2U2U2 · Posted: Tue Oct 14, 2014 12:21 pm Post subject:

HFly AFAIK is gone. The last boards 2006... ? here in the USA.

THey did NOT have a unique mast base, the board shown is probably from the '99s which like those of that era did.

jingebritsen · Joined: 21 Aug 2002 Posts: 3371

if one has a base extension as near to zero as possible, then one would have, on paper, about 15 cm of extra mast showing at the top. are we all making more of this than required?

15cm is what in inches? just under 6 inches.

a 460 mast on the east coast usa is still pretty useful. i would have sold the sail with one.

i don't recall this brand having much to offer in sails that was ever targeted for much beyond part timers, intermediates or higher move on to something else.

U2U2U2 · Posted: Wed Oct 15, 2014 9:31 am Post subject:

bred2shred · Joined: 02 May 2000 Posts: 989 Location: Jersey Shore

He is running a 430cm mast on a sail that calls for 447cm luff. He should not have any mast sticking out the top of his sail. He should shorten the head cap as tight as possible and base extend 17cm (give or take).

sm

aleko.petkov · Joined: 10 Sep 2014 Posts: 9

Thank you all for your comments. I have learned a lot.

I am indeed an early intermediate sailor. This is my first, and so far only sail.

This weekend I shortened the top strap to basically zero, reduced the extension to 18cm, and tried it out. Seems to fit fine. I can't say I noticed much difference in handling, but maybe it was because there wasn't much wind. Attached are some photos.

As for the mast, it's a Chinook, but there isn't any other writing to indicate carbon content or stiffness. Since it's not the same mast that comes with the package (that one is 460), I can only guess what it is.