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-   -   How to use 2 fins with the Starsurfer or Kode ? (http://www.star-board-windsurfing.com/forum/showthread.php?t=11746)

Sailboarder 8th April 2011 08:36 PM

How to use 2 fins with the Starsurfer or Kode ?
 
I bought a Starsurfer 117 this winter. It came with two large area plastic fins of about 31 cm and a normal 38 cm fin.

I'm suprised that the 2 large fins are of the same area. I thought it would be better to have a smaller fin at the rear when I use a large on in the middle.

I have two small girls, maybe 30-40 kg. They are using 2.0 and 2.5 m2 sails. I think the CLR (Center of lateral resistance ) with 2 large fins will be way too backward for their small sail. And if it is not, will they be able to rotate the board?

Should I trim one of the fins or try to find an elusive small Tuttle fin ?

Thanks!

Roger 9th April 2011 08:51 AM

What year model is your Starsurfer 117?
I would try the 38 cm fin up forward in the center fin slot and the plastic 31cm shallow water fin in the back.
The real issue here will be getting the rig far enough back so that the Center of Effort (CE) in the sail can
get back behind the Center of Lateral Resistance (CLR) to allow the board to sail upwind.
Put the mast base as far back as it will go and still remain attached!
Your girls cannot just "rake the rig back" far enough to sail efficiently upwind becuase when the rig is raked back that much, it has no power.
This has to do with very tiny sails and the distance behind the mast to the CE of the sail.
It's only 2-3 inches, but the mast box is 6" or more forward to the LE of the center fin.
Small Tuttle fins should not be too hard to find. It's a training situation, so used fins with a
little damage (you can clean up the edges and the foil yourself) in the used fin/bargain bin
will work fine.
Put the smaller fin in the back of the board.
Hope this helps,
Roger

Sailboarder 9th April 2011 06:25 PM

The Starsurfer is a 2006.

The 31 shallow plastic fins seem to have more area than the 38, so I will put a 31 in front. I will try to find a cheap small fin to put in the back. When I try it, if it is not small enough for the girls, I might modify one of the plastic fins. I'll let you know later when the weather is warm enough here to try it.

Thanks!

Sailboarder 24th September 2011 05:23 PM

I found a small Tuttle fin, probably less than half the area of the Shallow 31 fin. A 2.5 sail works great with the mast foot at the back, the shallow 31 in the center slot and the small fin in the back. I guess the 2.0 sail would work too, but it didn't see a lot of use this summer.


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