View Full Version : Formula or isonic 155 for max speed ?

9th June 2007, 05:50 PM
Which would be quickest off the wind (ie maximum speed ignoring upwind abilities) a Formula or an isonic 155?

Say using an 11m sail or perhaps a 9.5m sail

15th June 2007, 01:11 AM
A deafening silence from'Our Team' on tht one then..................

Must have touched on a sore point.

Just what is wrong with the isonic 155 ?

Nobody seems to have a good word to say about them.

Ian Fox
15th June 2007, 01:43 PM
Hi Peter,

Silence might ne more to do with "how do we answer that one..."
rather than the iS155 being "wrong".

Basically the iS155 (iS145) will be an easier board to sail fast off the wind in powered and choppy conditions, which gives potentially a quicker solution HOWEVER you do also need to consider a bunch of other variable like rider skill/weight (ability to EFFECTIVELY make use of bigger fins or wider tails - or not) and also the critical variable of "how powered up" the comparison is - because in marginal conditions (say light to mid 11m) then (esp a more FW experienced and/or heavier rider) MAY be more efficent (read : quicker) on the wider tail (and/or greater fin) of a Formula. In powered 9.5m (or windier) conditions, most riders would probably prefer the iS155 for comfort/control/safety, even if the ride speed advantage was not quantum over FW.

If, at the end of the "quickest off the wind" comp, you also had to nail a fast jibe (or series of them, like maybe a slalom race), well then the added on water handling advantage of the iS155 would be another plus.

In general, the majority of riders see (perceive) slalom to be a more hi wind / hi speed discipline than "fast FW conditions" and simply don't consider a 150Lt board to be a "slalom" solution c/w 100Lt rockets.
Realistically, the wind range that a 150Lt slalom is going to be competitive over a well tuned/well ridden 111/122/133 is also pretty narrow. Having said that, there are many locations that don't enjoy full on slalom conditions and many riders who may be heavier - but still want to go "fast" , or even prefer a more passive technique - for these guys the iS155 is a valid option.

That may or not have answered the question,
but I hope it explains why :)

Cheers ~ Ian

15th June 2007, 11:06 PM

Ian offers a good response, but I would ask him to offer a little more.

I have no experience with the 155, but have raced the F175, F147 & currently the F160. Speed down wind in 20+ knots is mostly dependent on sailor skill, especially if the water is rough.

In flat water at 20+ knots, the 155 is likely to be faster, but what about in 1 meter chop? The board that is easier to control, probably translates to the fastest board?

Formula boards are amazingly fast down wind in rough water, but it takes a tremendous amount of skill and confidence to make it happen.


16th June 2007, 02:08 AM
The reason for my original question was that I was considering competing in the gps-speedsurfing.com formula rankings.

The regulations mean that the IS 155 would be classed as formula because its width exceeds 90cm.

So sailing on super flat water (at West Kirby) in as maxed out conditions as you can manage, in ideal for speed wind angle , I wondered if the IS155 would manage to go quicker ?

In the end ,because of lack of information, I have elected to go for a second hand F159 which seems a fairly safe choice - and I have to say it is a joy to sail with 11m sail.

Just how fast I will be able to pedal it - well that remains to be seen

16th June 2007, 03:32 AM

Although I haven't participated in the gps-speedsurfing rankings, I do look at their speeds on occasion.

I carry a gps on all outings, but haven't tried downloading anything on my very old computer at home.

My best speed on Formula is 27.5 knots on my old F147 a year and a half ago. Off shore winds gusting to 26 knots, flat water and an old Gaastra Nitro IV 7.5, Curtis 68 custom fin.

My goal was 30 knots, but I find it very difficult to get close. I hit 24 to 25 knots pretty often, but 26 & 27 are rare. I can't imagine going 30.

I may not be big enough (80kg) to go 30 knots, but it's fun trying.

Good luck to you.

21st June 2007, 03:30 PM

do you really think you are usig the right tool (FW) in winds gusting to 26kts on flat OR rough water?

Even a K86 5.3 does >30kts in that kind of wind in flat conditions.
iS133 in 15 kts and you'll be hitting 25+ all the time.
ST115 in >15 kts too rough or flat.

Erik Loots
25th June 2007, 05:58 AM
Ken for formul;a speed (I dont go with formula) go for 15-20knots wind.

It is hard to say but technique seems to be the solution. Try to get everything under control. Lift of your gear is the only thing that limits your (I think). Try to get a good lift.

Watch some pro pics are their stance on the formula board. 30 knots is for sure possible!

My brother did 30knots on a starboard Start with 230 liters! with 6.9 sail

He also hitted 30knots several times on Freeformula 168.

But (another topic here) he doesnt like the isonics (another story..)

28th June 2007, 08:20 AM
I find it very hard to believe that an average sailor could get to 30 knots on a Starboard Sart unless maybe on an ideal day at Sandy Point.

I would agree with earlier remarks about it being very difficult to reach high speeds or 30 knots on the wider style boards unless highly skilled.

My best speed on an 80cm board is about 28 knots, recorded with a GPS, as they say with GPS when the data drops the bullschit stops.

Ian Fox
28th June 2007, 01:47 PM
Hey Hardie,

That's my line... ;) ...except it's officially bullsh!t, rather than bullschit..

Cheers ~ Ian

PS ... The PiT doesn't have world monopoly on good conditions..
Horst on a good day could be a possibility. Be a hell ride though !
And little wonder a guy who does that doesn't like an efficent board like iSonic ;)

mark h
29th June 2007, 05:06 AM
Now that most of the proper high speed winds have left the UK & wont re-appear till the autum, a few of us are trying to climb the GPS-Speeding.com Formula rankings. Although they are basically course racing boards, formula boards are real quick (and fun) of the wind. Today, I'v added a formula session at GPS-SS for 5 x 10'sec average @ 29.2 knots, max display 30.5k & software max @ 31.3 knots. Not fast compaired to speed or slalom boards but on a 100cm wide board, the sensations are like a zillion miles per hour and it is fast enough to put me 3rd in the formual rankings (did a cart-wheel in the garden when I worked it out). Keep't switching between a C3 E 67cm & a Select Ultra 58cm, neither where right for this day. So I'v just bought a Deb 63cm tonight to make sure I'm covered for the next formula session. I had 32 knots on the dial last year, but was'nt using GPS-SS then, so I cant prove it. I'm confident that these boards could, on the right day do 33/34 knots. Only problem is that, to do these sort of speeds, you need low to mid twenty knot winds & you could be on something much smaller/sleeker so it means missing out on a good slalom board session. Today, I could have been hitting mid 30's on my Sonic 100/7.6m Warp, but I did'nt take it with me to avoid temptation as the formula rankings was on my mind.


Ian Fox
29th June 2007, 06:16 AM
Hi Mark,

That's definitely good going - and also highlights the very real difference between peak "top speed" and speeds over 500m , 10 Sec or 5 x 10 GPS speed.

Based on what we have seen from good FW guys in good FW conditions (for GPS speed) anything near a "30kts" 5 x 10s GPSSS is plenty fast in FW terms.

There's no doubt the Formula speed rankings can be a very valid comp, one of the reasons it was introduced and supported in the first place was it really opens up the "competitive" conditions to just about anywhere (especially as a lot more water around the world is a lot more flatter at 20 kts windspeed than at 40..).

Also a lot more guys with access to Formula equipment than specialised speed gear.

Chers ~ Ian

PS : Same problem for me ; my FType has been hanging around dry for nearly 2 years now for that GPSSS mission, it never ever got near a run on anything like half decent conditions in favor of smaller, sleeker equipment. ;)

29th June 2007, 07:18 AM
Hey Foxey,

Sorry about stealing your line!!!!

GPS is an amazing tool, allows you to be more scientific.

I realize now that I was way over estimating how fast I was travelling before I got one. Even now when I sail with a GPS, I tend to way over estimate how fast I'm going in very choppy conditions....... It'll go something like this..... "WOW that must have been at least 35 knots, looks down at GPS 30.66.... No way that must be wrong!!!, and then bugger, how do guys do 40knots in chop?".

The other thing with gps it allows you to measure a variety of aspects of windsurfing: On our GPS Teams Comp in OZ, www.gpsteamchallenge.com.au we are using: 2 sec peak; 5x10 sec average; NM; 1 hour' Alpha 500; and Distance travelled. Each category requires it's own technique and discipline, and is a great learning tool.