Which fin length for Patrik Hybrid 91 Airinside?

    Hello!


    I recently bought a Patrik Hybrid 91 Airinside and I want to use it with a fin for light wind slalom/formula cruising. Anyone here who has this board and knows which fin sizes work well under it? I thought about rebasing some old formula fins to use under the board.

    I had this board and for Fin-Windsurfing I used an 48 cm Chopper - mit Avanti Machine sail (I think 8,4).


    It was a very good combination - but against the Phantom Foil-Set which I bought for the Hybrid 91, too, the fin-combination lost completely.

    Thanks for the reaction! I can believe the foil setup was earlier to get going than the 48 cm fin with 8.4m sail. I plan to use 9 and 10m sails with this board. 48 cm seems small for a 91 wide board...but I never used a 8.4m sail on such wide board. I will try my Carpenter 47 cm fin with 9m sail.

    The Chopper is a perfect powerfull fin - sail was 8,4 Avanti Machine, than Phantom Iris sails.


    From my personal experience: it's not worth. The combination with the fin on the water is in all point inferior to the combination with a freerace foil.


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    Hi t36,


    I understand your reply about the advantage of the foil but I tried foiling and to me it's something entirely different. The feeling is entirely different and I like windsurfing on the fin much more. Even if I need bigger sail sizes to get going.


    I have a Patrik Formula 180 Airinside too and use it with 11 and 12m sails. In those conditions I don't even see a lot of foilers because they can't fly unless they use big sails like 9 or 9.5m. On our homespot we see a lot of windfoilers but in really light wind the wing foilers are the first to fly it seems.


    There is a simple rule of thumb that says the right fin size for a board is the width at OFO x 0,75. In this case the OFO is 77 cm so the right fin size would be around about 58 cm. This is for a sail size that is ideal for the board and that is dividing the board width in cm by 10 and than you get the ideal sail size in square meters. You can add or subtract 1m surface so sails of 8 to 10 square meters would be ideal following these rules of thumb.


    This is only a startPoint because you just have to try fins, sails and setup like footstrap positions and see what works well. That's a really fun proces too!

    To find the "best" fin for the hybrid 91 PD AI - I discussed the fin type and length with Patrik Diethelm and Ludo Jossin.


    Compared with my AI Foil 190 - the hybrid 91 is one size smaller (volume and thickness) - it's not comparible at all.


    Even with the Chopper 48 cm the speed feeling was significantlyinferior to a large dedicated full-SL-finboard. It's a compromise between Foil and Fin.

    And therefore, these boards died without successor.

    That's good to know. I won't set my expectations too high then.


    But still I'm convinced a 48 cm fin is too small for this board. A wider OFO asks for more lift and That's why this rule of thumb of fin size = OFO x 0,75 works well with as good as all single fin boards. So I will try it and I will let you know.


    I asked Patrik Diethelm which fin type I would need for my Formula 180 Airinside and he said he didn't know because the board was mainly used for foiling. So I tried the fins I had and bought some others until the feeling was right (and the GPS speeds were ok).

    I had a first running on this board yesterday. I started the session on my Patrik slalom 140 Airinside with 8.4m Duotone Warp. When the wind dropped a little I just put the 8.4m on the Hybrid 91 with a 64 cm Kashy sXs formula fin.


    I thought the fin might be too long but I didn't have any other fin In the range of about 58 cm which should work according to the rule of thumb of OFO x 0.75 so I just tried it.


    The combination was pretty ok. Maybe the fin is a little too long but not so far from ideal. I did about 20 km on this setup with gusty wind. In the luls I could keep the board planing, in the hard gusts, I was afraid of the aggressive acceleration but the control was ok. I could go really fast for a board this size with only 8.4m sail


    After the session I went to pick up the formula fin that was rebased from 70 to 58 cm. So next time I will be able to try that fin. But for now I'm already happy with the performance of this board. It goes through lulls like nothing else and is fast. Pointing is really nice too.