View Full Version : iSonic105 technical ride

28th August 2006, 10:05 PM
Hi Ian,

I?ve just bought an iS105 which replaces a Carve111. My other board is a HS133 and I found that C111 and HS 133 have a bigger overlap than I antecipated. So it made a lot more sense getting an iS105. Conditions are flatish, fresh water lake and winds tipycally gusty from 6 to 15 knots, ocasionally 20+. Sails Gaastra Matrix 5.5; GTX 6.5 and Severne OD 8.5. My weight 66Kg.

Now the questions.....Starboard defined smaller iSs as requiring a demanding and technical ride it would be nice if you were more specific about that definition. In other words what should I expect from the iS apart from lots of speed.

Another one ....although I really love my HS133 maybe it is time to move on. As it is my "big" board I was thinking about replacing it by an iS135 or 145.
How would you compare them? Is iS135 also hard to exit jybes with decent speeds which is IMHO the only HS133 fault?

29th August 2006, 01:03 PM
I think you will find that the iS105 and the HS133 has about 97% overlap at your weight. If your biggest sail is a 8.5 I really don't see a need for any bigger board. On the other hand, if you want a board that complements the iS105 I think you should look at something like the smallest Kombat. or maybe a pro-kids S-Type from last year.

29th August 2006, 08:46 PM
With "flatish water - typically gusty 6 to 15 knots" as described above, for the HS133 replacement, I would say go for the iSonic 135 or the iSonic 145 (Former F-Type 138). You could even go for the iSonic 155 if you added a 9.5 or 10.0, and gain alot of early planing.

I have an F-Type 148, use it with 9.5/8.5/7.3.

Jibing is similar to formula boards but much less stiff, but still requires that "wide board" technique. But early planing capabilities are fantastic.

If you did the 145, I bet you could get away with 8.5/6.5 (6.5 when the water is still not too choppy) and get something smaller for when the chop picks up (like the iSonic 105 as you suggest above) for 5.5/6.5.

Or you could go with something like a Kombat if you want better manuevering/jibing, but not one of the smaller ones as PG suggest above, at 5.5/6.5 a 107 or 97.

My middle board is iSonic 125 (lots of overlap with my F-Type 148, I know and I like it that way) and smallest is Carve 122 which I plan to swap for a Kombat 97 in the spring.

Nice of Starboard to give us so many good boards to choose from! :)



29th August 2006, 10:05 PM
Thanks PG and MA_Pete,

I?d be very happy if I could plane in 9 to 10 knots with iS105 on a 8.5, which I can on my HS133 and could not do on C111.Maybe my technique is not that good I?ll check it out when I put my hands on the iS105.

In fact I was wondering whether iS135 planes earlier than HS133. The target is to gain a knot or two and stretch my quiver range without adding a bigger sail.
I?m not sure if I?ll get it buying iS 145 without a bigger than 8.5 sail hence my question.If chances for that to happen are too little then I?d go for iS133.
What are your sailing conditions and weight?

29th August 2006, 11:53 PM

My weight is 72 kg and conditions are flat to light/medium chop in salt water bay.

If you are looking to plane early on an 8.5, iS 105 at 63.5 cm wide will probably not do as well as 77 cm wide HS 133. I would look to iS 115/125 for that. iS 115 would be best if you want it to be good with 6.5 & 8.5, iS 125 if you want earliest planing with 8.5. (Boards mag in UK tested in June 2006 issue, felt iS 115 best range was 6.5-8.5 and iS 125 was 7.0-9.0.) iS 135 would probably be okay too, but would be too big for your 6.5. But it would likely plane earlier than the 125 and for 8.5 only would probably be fine. (See Grant's thread from a few weeks back on the Star Bulletin Board raving about the early planing of his iS 135.)

I have iS 125, it is great with 8.5 and 7.3, haven't got out on it yet on 6.6.

For your smaller board for 5.5/6.5 use, I would say iS 94/101 or Kombat 97/107.

My 2 cents based on my experiences with the Starboard lineup.



1st September 2006, 08:30 AM
I'm at 65kg and have the iS105. I love this board when the winds are steady and strong. At my weight, I find it is a great board when I don't have to worry about the wind changing directions without warning or experiencing lulls.

I was using my iS105 with a 7.7 and the 34cm fin this past week. What a great combo. The lake had 2 miles of fetch, and it was a bit choppy. But with the sail fully powered up, I found it very easy to control.

Using this combo when the wind wasn't as friendly, I found it very difficult. When this happens, I use my FType 148 with the same sail.

I don't have an 8.5 to use on my iS105. My next larger sail is a 9.8, which is a great one for the FT148.

2nd September 2006, 08:17 AM
Hi MA_Pete and 02bnme,

Thanks guys!
I intend to use my iS105 with 6.5 and 5.5 sails I suppose it will be fine.
My previous doubt was if iS133 would plane earlier than HS133 both with 8.5 sail. Anyone with that experience?

Ian Fox
2nd September 2006, 09:51 AM
Hi Ricky,

The iS133 and HS!33 will plane pretty similarr with 8.5m in normal use, there are differences in technique to get the HS planing in marginal c/w iS (in HS you can work more against the rail/concaves in sub planing ,in iS you have to pump more towards pushing the board/effort FORWARD not so much sideways as HS), if the rider is really good with one shape(technique) they may find some advantgae but it is pretty small.

Cheers ~ Ian

4th September 2006, 08:48 PM

Thanks a lot.
Do you think I would plane a couple of knots earlier on a iS145 compared to iS133 both on 8.5 sail?

Ian Fox
5th September 2006, 12:24 PM
Hi Ricky,

You mean iS145 vs iS133 (as above) or iS145 vs HS133?

For iS145 vs iS133 the answer is yes, about 2 kts at the critical marginal planing wind/s for these boards.

For iS145 vs HS133 the answer is half yes, about 1-2 kts at the critical marginal planing wind/s for these boards if not super efficent HS technique used.For riders that have really good HS early planing ability, they narrow down the gap a bit.

Remember too, with HS vs iS early planing comparison, you also need to consider the overall board+fin combo : with iS145 it's more big fins (52-56cm), whereas with HS133 it's more often 44-48cm.

Cheers ~ Ian

Cheers ~ Ian

5th September 2006, 01:52 PM
I am somewhat surprised of the "consensus" to recommend huge boards for featherweights (at Ricbra's 66 kg). The iS133 is 80 cm wide, and the iS145 is almost 90 cm wide...

I would think that the law of "diminishing returns" comes into effect quite quickly. With the same sail size it ought to be more fun to have a board that planes almost at the same time, but is much more manouverable.

For a small guy it seems that a board around 70 cm (like iS115) wide would be sufficient as a lightwind racer, especially with decent pumping technique.
On the other hand, if the wind is strong enough for a 5.5 then a much smaller board would make sense. One with an optimum sail of about 5.5 and a max sail of 6.5. This ought to be not much wider than 60 cm (with a corresponding volume of about 95 liters, offering float like a barge).
My honest opinion is that the iS105 does not fit particularly well into a two board quiver for a 66 kg guy... It is too small as the biggest board, and too big as the smallest.

5th September 2006, 11:59 PM
I weight about 70kgs, and I tend to agree with PG's comments. Very high volume boards really won't buy you much unless you also focus on matching them with very large sails. Given a sail limit at 8.5, I think that I would limit the board size to the iS111, or maybe the iS122 tops. Personally, my biggest board is about 115-120 liters, and my biggest sail is 8.3. While I can't claim to plane off in 6-8 knots, I find no difficulty at 10 knots with reasonable glide through the lulls. I think that it's important to remember a change from the freeride Carve to a iSonic slalom will most likely give you both a higher speed potential, to include a quicker planing capability, with the quicker rockerline.

However, before you go too far down the road, I would give yourself a chance to experiment with the iS105. Although an 8.5 is a bit large, you might find that it will tolerate it well, especially if you match it up with an appropriate fin.

6th September 2006, 05:34 AM
Hi PG and steveC,

While I do tend to agree with you based on commom sense and physics my own experience leads me to a different conclusion given certain conditions.
IMHO in fresh water and gusty winds more volume won't hurt much either way low or high winds. Example: with my C111 and 6.5 GTX I?ve never felt it to be too big for that sail size at the conditions above. However with the same combo but at a sea bay my C111 felt really big. I could have gone few liters less easily.
Same experience when I went to Aruba where I could easily sail smaller boards compared to my place when powered up by same sail size. So density of water and wind play a considerable difference.
I might be wrong in my conclusions but so far I could not think of any different reason for.
A little more volume puts you on a place sooner and if the gusts are not long enough you might keep slugging with a smaller board.
My point is how much volume versus sail size will work better?
I'm not a FW guy and do not want to go that way but I think I would plane in 7 knots with FW and 11m sail. Having said that what would be the earliest non FW planner for a 8.5 sail?
I wish I had the opportunity to test different sizes to compare them and make the right choice.
I'm glad I can use this forum to get some valuable opinions and experiences though.

7th September 2006, 12:44 AM
Hi Ricbra,

Other than my trips to the Columbia River Gorge and the Delta (east of SF Bay), it's pretty rare for me sail in fresh water. But, even when I have, I really haven't noticed much difference in my ability to plane. However, I'm aware that inland locations can have very different wind, especially if its dependent strictly on thermal conditions in combination with certain types of topography.

I understand your point that a bit of extra volume is your friend in gusty up and down wind. Yet, for myself, I view volume more in terms of simple float rather than the key to early planing ability. In my mind, the character of a board's rockerline is what makes the real difference. Of course, most high volume boards tend to have flatter rockerlines that promote early planning.

The real question is how big to go. My limit is about 120 liters because that's tons of float for me. Really, 100 liters offers me excellent float, and it readily supports a 7.0 sail, so it's a more desireable choice most of the time. But, if I need to go with an 8.3 sail because of real light winds, I need the bigger board and fin to support it. Given the fact that you have set your sail size at 8.5, and because your focus is not oriented towards a FW upwind/downwind approach, I doubt that volumes greater than 120-125 liters will not buy you much.

Another way looking at the situation is in terms of maneuverability. Sticking with just the needed volume, I find that I get to maximize maneuverability and nimbleness. I guess that is why I recommended that you experiment a bit with the iS105. You might be surprised.

Ian Fox
7th September 2006, 09:19 AM
Volume usually also means width and surface (planing) area in modern boards, which in turn (usually) help the effective and efficent use of larger fins ; both factors definitely provide early planing and marginal conditions advantage/s. Especially for lighter riders (who will be overpowered by sail earlier in the gust/s), a gusty conditions combo of slightly more "board" (read : volume and planing area and fin) with a smaller sail can really be a more advantageous (and more fun) option than more sail on a smaller board in the same (gusty) conditions.

Likewise, in gusty (and moreso offshore) conditions, the chop (vs windspeed) doesn't normally develop so badly (relative to filled in wind at the "same" speed, and/or more onshore conditions). Accordingly. the disadvantage of having too much board for the chop arrives later in the range of gusty/offshore conditions than filled in, or more side/onshore conditions.

Likewise, if you really analyse it deeply, often in gusty *marginal* conditions, the gust/s just don't last that critical time to allow the rider to pump the board fully thru to the plane, and the board always seems to be "sticking" (c/w a more filled in wind at the same "speed").

In those gusty *marginal* conditions, carrying the extra volume/area/fin can often be the key advantage to getting the gear planing, and then it just keeps running. Yes, for sure, some guys are pumping and early planing wizards, (and others very legitimately choose and tune not to be.. a very important personal choice) but even the wizards can still struggle when it gets marginal enough. Naklua. Last week. :)

Cheers ~ Ian

[ Sidebar here is that a skilled sailor won't statistically (numerically) need much more wind to get an iS101/105 planing than (say) iS133 or iS145; but the available power from a wind variance of just 1 or 2 kts in that threshold range is very significant. Worse, when it is gusty, or not clean wind in that range. If you're sailing a lot in that zone, the difference can be everything. ]

I'm into speed and small, but planing slow is always faster - and funner- than not planing :)

hans kleingeld
7th September 2006, 09:59 AM
Very clear explanation Ian. Last Monday I used the iS105 with OD7.5 in gusty conditions 12 tot 20 Kts. With my weight of 95 kg the iS105 really isn't a good floater:( in windlulls. The shallow water was saving me a couple of times:o. In deep water, but also for planing through the iS125 with 7.5 would have been the best option to make most fun concerning planing time and about the same topspeed:p!!

7th September 2006, 09:47 PM

Thanks a lot for putting in a clear way what I do feel at my place.That is exactly what I have very often.
Many times winds are in the 6 to 10 knots range when with HS133 and 8.5 I can plane at the gusts with proper pumping but never could with C111.
When it is a bit higher say 8 to 12 knots then I'm planning almost all the time thanks to the amazing capacity of keeping on a plane that HS133 has, and here again I believe the extra volume makes the difference.
I believe and am eager to prove it that at such conditions I'll struggle a bit with iS105 as it will stop planning way sooner. I'll see.

One interesting point is that I can plane a bit sooner with a 38cm fin of same design and supplier - I guess - than stock 42cm. It seems to be less sticky. It also doesn't point upwind as well though.

steve C

It's really interesting to see how people make their quiver choices. It does make a lot of sense I also like less weight and nimbleness it's much funnier .I'll follow your recommendation and see how much iS105 and HS133 overlaps before deciding which iS to get although it will also depend on what will be available:).