Different technique required for isonic 101 for speed compared to traditional shapes?

[Marko]

I spent some more time on is101 and found some things that made me faster.
I raised my boom quite a bit comparing to my old sonic and I set my footstraps really tight so my feet are very much at the edge of the board. I also played a little bit with mast base and found that it is faster when back. It was really choppy so I had it in the middle position, but I think that in flat water and downwind runs it could be really good if placed back.

I also found that I had to adjust my stance with isonic compared to sonic. I am much more far out from the board and a little lower, similar to highwind formula sailing so I am also thinking about longer harness lines also.

By the way, what is your best speed on is101?

[ned_321]

Best speed so far 63.3 kmh (2 second) with 7.4 sail.
On it's predecessor (SX 106) I got a GPSmax of 68.4 with a 6.2 sail, and multiple 65+ on 7.4 sail. So still missing at least 3 kmh.

On the IS87 however, things are getting back to normal. Clocked 72.7 during last USM.

[ThierryP]

Ned_321, Ronny is right, 35 is much too big on a 6.2 for speed. I have sailed my 06 105 with a 6.6 TR-1 using a 28 cm Tectonics Goldwing fin, with very few spinouts, and I am not such a good sailor. You can surely go much smaller than 35 on your 6.2.
Anyway, I do not think that all-out downwind speed is these boards' strong point, it is rather their speed on all points of sail, especially upwind and on a beam reach, and ease of use.
Let us know your speed after you've dropped fin size.

[ned_321]

Hi Thierry,

Until now, I only used the 7.4 sail on the iS101. Hence the 35 fin.

Will try a shorter fin (30 or 32) once I get to use the 6.2 sail.
Spinout is not the problem. But with a too short fin you don't get enough lift; then the board does not run free and high.

I know from experience that a small fin is key to speedsurfing. But there is a limit to how small you can go. Once you're under-finned, you go slower instead of faster.