View Full Version : iSonic 87

17th August 2007, 01:49 PM
Hi my name is Alex Nielsen and I sail in the race in the gorge where we have course slalom style racing and I feel like sometimes my Gsport sr6-b 34 doesn't feel like enough. Do you think that I could bump up to a Tectonics Goldwing 36?

Sincerely, Alex Nielsen

17th August 2007, 04:10 PM
Have not sailed the isonic 87.

But under the Isonic 105 I own, I would not go any bigger than Goldwing 36. The goldwing fins are less powerfull than the SR6-B fins, so the 34 SR6-B would be good in the same windrange/chop than goldwing 36.

17th August 2007, 05:04 PM

I dunno if 36 cm is too big or not for iSonic 87. Most users on french forum have 28-32 cm fins :


Cheers !


17th August 2007, 09:30 PM
Hi Alex,
I have raced twice in the gorge and for that, I would go with the 36, it shouldn't be a problem on the 87. On the competitions in the canary islands, hardly any starboard rider went below 32cm fin, mostly used 32 and 34. With the wide tail, you don't want to go to small on the fin, specially with a upwind course like the gorge.
One other think you can do for the Upwind course which helps a lot, if you want to stay with the 34cm fin, is put your boom lower than you are used to, that way you won't have that feeling of wanting to bear away.

18th August 2007, 12:42 AM
Hi Alex,

I'm a bit curious about what size sail you're using most often in combination with your fin. While I don't have an iS87, my newest slalom board is about the same size. I have been using a Tectonic Goldwing 34 and a F-1 Falcon 32 in combination with my 5.6, and I've found that the 34 works superbly. The F-1 works very well too, but it lacks the drive of the Goldwing. If you're using a much bigger sail, I would think that going to the Goldwing 36 would give you more robust upwind capability.

If I were you, I would stop by Sailworks in Hood River and see if they could offer you a demo 36 to try out. It would be good to size things up before spending the $185. In any case, there's no harm in giving it a go.

18th August 2007, 01:11 AM
It just goes to show how hard fin selection is. I use my 87 for speed and find the stock fin too big in almost all cases even with my 85kg bulk pushing on it. I now mainly use 27, 29 and 31 F1 Falcons.

18th August 2007, 03:57 AM
For speed, I think you are right, those are probably the right sizes, but for upwind course like they do in the gorge, you simply can't get upwind on a fin that small.
I think what wilhm shurman said is right, for going upwind, you can go up to 36cm on the IS87 no problem.

Ian Fox
18th August 2007, 06:49 AM
In the Gorge sailing with (or against) current of the river makes a fairly unique set of tuning c/w open water. So what works there in practice can also be slightly "unique" c/w open water or more general tuning.

Also worth noting for reference that in tuning/selection differences as fine/subtle as this, that the "performance size" of the fin has as much (or even more) importance than the simple mechanical size (depth) alone.

[ For example : A powerful 34cm can easily outperform a not so powerful 36. Goldwings (with fine, narrow tip) tend to (performance) size slightly less (for a given mechanical size/depth) than some others. SR6b size about mid to slightly small depending on if used under or over powered (also depends on version, and noting Alex says Gsport version, I am not really sure on that version). By comparison other fins like Drake Pro (for example) tend to be at the bigger performance size (for given mechanical size) and/or also have a better performance in light to mid powered conditions. ]

Typically, amongst "good" slalom fins, the "value" of these these differences tend to range about +/1 2cm. So 34 type "A" may or not equal 34 type 'B" or be equiv to 36 type "T". etc.

This may all sound a bit too precise (agree) but if it comes down to a debate over 36 vs 34, then unless it's within identical make/model/stiffness (etc), consideration of performance size is critical - and mass debates over mechanical size (depth) alone can be misleading in some circumstances. ;)

Cheers ~ Ian

18th August 2007, 10:24 AM
The tectonics 36 has a bit more area and is more upright.
Would I do okay on it with a 6 or 6.6 on a broad reach??
I am quite light and weigh around 140 since I am only 15.
I pass a lot of people in the corners but they get me in the upwind leg.
Also thanks Wilhelm for the boom height tip. I overlooked that possibility.
Thanks much!!

Sincerely, Alex Nielsen

18th August 2007, 05:32 PM
For what it,'s worth - I don't agree with Phil that the stock fin is too big.

I'm 82 kg and sailing the 87 with 6.4 on flat water and I find the stanadard 32 Drake to be perfect.

For a bit of extra (1 - 2 kts) off the wind speed when really powered up I use 30 falcon but the stock fin is a better alround option and easily capable of 30kts plus. - and goes upwind like a dream.

19th August 2007, 02:05 AM
This thread just goes to show how personal fin choice can be. Here in the UK it's very hard to try before you buy when it comes to fins and that probably goes for the rest of the world. Both Duncan and I found the stock 32 too big. Peter and at least 3 others found it right while a couple of guys at Weymouth last week found it too small. Fin choice is a real minefield and in some cases it can be quite exensive to get wrong.

Here in the UK many of the shops only stock Select fins and often only either wave fins or freeride fins depending on the shops location. For the stockist it must be really hard to have a range without having loads unsold gathering dust.

Luckilly windsurfers are a friendly bunch on the whole and will often lend you a fin to try.