View Full Version : iSonic 125 Speed tips

14th September 2008, 03:43 AM
I have yet to break the 30 knot barrier on a 125 iSonic, and seem to be stuck around 28kts. Of course ability is probably the most important factor in going quickly, yet I seem to get slightly better results from my 2000 Carve111 though usually on a 5.5 and in higher winds. I am around 85Kg and sail the iSonic with 7.5 or 6.5 Tushingham Thunderbirds with which I am using stock fins of 44 and 36cm. I sail inland so the state of the water is relatively flat. I love to sail the iSonic especially on the 7.5 when I can lock the sail down and just blast around.

Other than sailor ability I guess that the next major component in gaining a few kts would be sail choice? I enjoy the rotational freeride sails yet am aware that a more race style sail would probably give me a speed boost. Assuming I had the ability, what sort of speed advantage would you expect from a change to a race sail?
My fin choice is typically dependant on sail size, so I choose the bigger fin with the larger sail. Would you expect to go quicker using the smaller fin with the 7.5?
Anybody know the max speed the iSonic 125 has reached?
Thanks in anticipation.

14th September 2008, 05:08 AM
Hi Steve

Funny you should bring this up. I have just got the I1222 and sailed it with 8.4 RSR and 46cm drake. I'm about 85kg. Off the wind I did 31 knots. For top speed there is no doubt you need a race sail or at very least freerace. Pairing up the right fin is important, as is rig tuning and how broad you sail.

With the 7.5, you would expect 30-34+, however a 38/40 fin would most likely work best. Remember for speed sailing crank on an extra .5cm of downhaul. This will give you the effect of the board starting to lift a little on a reach/upwind, but you will fly off the wind, where the best speeds are (120-130 degrees).

You will have a lot more chances in 7.5/125 weather to go over 30, than by going bigger in sail size. A race sail will give you a slight edge, but a correctly tuned freerace is almost as good especially when going broad.

Good luck

15th September 2008, 05:48 AM

Your rotational sail is not ideal match with iSonic (especially if you want speed)
Your fin (44) is too big and probably not ideal either (1st generation iSonic stock fin?)

Try/borrow/demo some cambered sails & race fins, you might be surprised.

mark h
15th September 2008, 10:36 PM
Hi Steve
Your iS125 will be good for 35k in the right conditions. As well as the right sail tunning and fin, water state & wind will be key.

To get low to mid thirtees, you'll need to find a strech of super flat water (near the shore) and wait for a day with the right wind strength (20-30k) and angle (120-130 degrees) and fire it up. Only real problem is, you will be out on big kit in wind strengths where someing much smaller & sleeker will going faster. But the stronger winds are needed.

I managed 32.4 on the older Sonic 125, but made the big mistake of using a 49cm fin. A 38cm on that day would have given me at least 2knots or so faster. Heres the session details:

Date Friday, 16 March 2007
Spot West Kirby, United Kingdom
Board Starboard Sonic 125
Sail North Sails Warp F2004 7.6
Fin Select Superfast 49
GPS type Garmin Geko 201
Average speed 28.22 knots ( 30.1 29.3 27.4 27.4 26.9 )
Max. GPS (display) 32.3 knots
Max. 2 sec. (software) 31.5 knots
100 m run 30.1 knots
250 m run 30 knots
500 m run 28.1 knots
Nautical mile 16.6 knots
1 hour 7.9 knots
Distance 33
Windspeed 15 knots
Gusts 20 knots
GPS type Garmin Geko 201

15th September 2008, 11:13 PM
About two weeks ago, I had to use a fin of a friend of mine for my isonic 125 and RS Slalom 8.4. I took a 52 north shore (the Dunkerbeck series, in blue). It sounded like it would be way to big, but had no choice so tried it anyway. Felt good for the really low end, but a little big when the wind picked up.
BUT: I did 30 knots !!! faster than ever before on this board and RSs8.4- so a PR.

For me this this coincidence leads to a new way of tuning my isonic 125: bigger fins than I used to use (the 44 drake slalom pro for this 8.4). Now i've bought a 48 cm Meanline... yeah!!

PS1: for RS4 7.8 I use Sr7b 42 cm, for RS4 7.2 I use a Tectonics Goldwing 38 - really good for the isonic 125 and 7.2
PS2: I changed the regular straps for Starboard Racestraps.. Get them if you can, it will improve your speeds!!