Need Rig Tuning assistance

hamblett · Joined: 29 Jun 2000 Posts: 40

Sail: 1999 North Zoom 7.0
Board: Screamer II CGI (278cm long x 55cm wide, @ 103 Liters)

Problem... Back leg is always straight and loaded regardless sailing angle. I Cant bend the back leg and crouch over it comfortably. The only thing that was comfortable was a bent front leg and a straight back leg. UGHH! Bad technique!

I Was sailing in fairly flat water in 15-20 mph. Med to Max Downhaul and min to med outhaul. Boom set to Mid or slightly higher. Tried different harness line lengths and the shorter they were the more it helped but not by much (helped out my aching hands more).

Started mast base in the middle and then tried pushing it forward with little results in either position.

WHAT GIVES! Is it just me? Why cant I get this sail/board combo trimmed out! I put up my 5.0 later in the day (20+mph) and was as comfortable as ever. Straight front leg, crouching over the back leg, riding the fin. No problem on the 5.0. No can do on the 7.0.

Please help!

spyder · Joined: 24 Sep 1996 Posts: 2790 Location: oahu

I think the board is too small for the 7.0. You need something in the 285+ range. The most you can hope for on a 278 is a 6.5 and thats pushing it.

I have sailed the Zoom (6.5), it is a nice sail, but almost like a race sail. Kinda heavy, but excellent stability. So, the sail is fine, but it needs a lot of downhaul.

sorry if thats not what you wanted to hear, but I think thats the main problem.
other problems could be, that the harness lines arent balanced with the Center of Effort, but you cant get it right unless the board is long enough from the
mast base location to the foot straps.

So that is why the 5.0 works fine, but going to the 7.0 is past the geometry of the board.

jhanrah1 · Joined: 08 Jun 2000 Posts: 31

SPYDER is right the board is too small for the sail. The screemer maxes out with a 6.5 and thats pushing it. I sail a 285 astrorock with my 7.5--and sail a 6.0 with my 274 fanatic bee. The 274 fanatic is like the sceemer,and the 6.0 is dialed in nice. So its not YOU its just the dynamics is off.

hamblett · Joined: 29 Jun 2000 Posts: 40

I can see where the 7.0 might be too big for that board, but why? Is the reason directly related to boom length?

New question... If youre sailing a 6.5 on this board, where should the mast base be. Forward, mid or aft?

I was told that with a big sail like a 7.0 that I needed to put the mast base as far forward as possible due to the long boom length. Does this sound right?

Yes, the zoom is heavy but because its pretty much a race sail, it has great range and is very stable (which I love!).

To keep costs down, this is the only board I own at the moment. To increase my water time, I have to try and make this sail work as well as possible on this board. Im a cheapskate, what can I say. $1,400 for a new board is A LOT of money! Especially for the Drops 96 that I want!

spyder · Joined: 24 Sep 1996 Posts: 2790 Location: oahu

it all has to do with the sailors position with the Sails balance point (Center of Effort). The distance from the where the mast track is to the footstraps dictates what sail range can be used.
Farthest forward on the mast track would be the largest sail, and the farthest back (towards the footstaps) would be the smallest.

as the sail gets larger, the COE moves farther back, which needs a bigger board, in order to sheet in and sail comfortably.

Most commercial boards have markings on the mast track indicating where the mast base should be with respect to the sail size. on your screamer, the biggest sail probably would be a 6.0-6.5 and the mast base would far forward on the mast track.

As for making the 7.0 work on the screamer, try putting the mast base all the way forward, and move your footstraps all the way back. If the fin position is adjustable, move that all the way back. this will give you the longest distance possible on that board, and it might work..but barely.

hamblett · Joined: 29 Jun 2000 Posts: 40

Thanks for the info. This makes very good sense. best definition Ive heard yet of proper mast base position.

The board (screamer II) has cm markings defining mast track position. Any idea how to correlate those readings into sail size? Or is it one of those things that you just need to try and then record the cm readings?

Thanks again for the input!