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View Full Version : Why does my weight affects the sailrange of a board ?


jogi1111
9th October 2008, 05:05 AM
Hi Starboard Team,

how come, that the upper sailrange of a board is depending on the weight of the surfer ?

The answer for the lower sailrange is quite clear: heavier surfers can handle a specific board even with a very small sail, means in higher winds, when lighter sailors start losing control.

But what in very light winds and with the upper sailrange ?


Just to make my question clear:
Take the iS122. The "official" sailrange rans from 6.0 to 9.5
Take a rider with 70 kg and he would have no problem to sail a 11.0 on that board at light wind (I can !)
But take one guy with 100 kg - and he should better not go further than the 9.5, 'cause it starts getting uncomfortably for him.

Do you have any idea (even weird ones) how this effect might be explained ?


Cheers Jogi
__________________
Who stops getting better, has stopped being good. (Philip Rosenthal)

Screamer
9th October 2008, 03:29 PM
Jogi

Have you ever felt you've put a sail too big on any board? What happens then and how do you know it's too big? You gain nothing in early planing, handling is horrible, you may even start to sink.
Heavier riders will experience this with smaller sails than you. There's simply way too much weight and bulk on a board to carry. No scientific explanation here, but tried and tested many times.

Btw, I don't think that you can use 11m on an iS122 efficiently at any body weight. There are much better boards for that.
With regard to quoted sail ranges, I think they are a bit stretched: I use iS122 (85kg) and I think its ideal sail range is 7.0-9.0, maybe 9.5 if you're lighter.

Jean-Marc
9th October 2008, 04:03 PM
Take the iS122. Take a rider with 70 kg and he would have no problem to sail a 11.0 on that board at light wind (I can !)


Jogi,

I respectfully disagree. The iSonic 122W75 paired with a Select RS7 55 cm fin and a Code Red 11m2 sail is a total pig when sailing upwind: zero upwind pointing ability. By comparison, HS105 is vastly superior (a few degree less than a dedicated FW) followed by iSonic133W85. Rail shape, scoop-rocker line, deep concave with a center spine, overall hull lenght, mast-track and footstraps inserts positioning more on the back of HS105 are apparently important contributors to such a large difference. Planing as of 7 knots is no problems with any of the 3 hulls with my 65 kg, however.

Upper wind range is as follows: HS105 (5.4 sail+ 26 cm fin) 25 knots > iSonic122W75 (6.6 sail + 32 cm fin) 20 knots > iSonic 133W85 (8.2 sail + 40 cm fin) 15+ knots. Wider and thicker boards just become less and less controlable in higher wind and chop, especially with too large a fin for me. Very small fins do not work on super wide flat-bottomed iSonic whereas they do work as a charm on the HS105 for my light weight.

As for a heavy weight 105 kg pal, he's on a FW + Code Red 11m2 sail in such light wind. Forget using small HS105 or iSonic 122/133: he just sink them all which is plenty inefficient in low wind range. Just to show that 40 kg body weight difference means a lot: to be on par with medium 12-18 knots wind, he's on a Carve 162 + 52 cm fin + 9.5 m2 sail combo while I'm on Kombat 86 + 30 cm fin + 6.9 m2 sail combo.

Cheers !

JM

jogi1111
9th October 2008, 08:35 PM
Hi Jean-Marc,


...The iSonic 122W75 paired with a Select RS7 55 cm fin and a Code Red 11m2 sail is a total pig when sailing upwind: zero upwind pointing ability. By comparison, HS105 is vastly superior ...

I totally agree ! ("No problem" was not, what I really meant. "Could be sailed" would have been better ...)
And what type of board will be perfect for me to ride a 11.0m sail, might be my next question to you, especially, as you might be in my weight range :)

Here, it's more about the effect, that lighter surfers can (more or less) comfortably sail bigger sails on the same board than heavy weighters. How come ?


As for a heavy weight 105 kg pal ... Forget using small HS105 or iSonic 122/133: he just sink ...


That's right - and the iS122 might be not the best example for the effect, I described earlier. But anyway: the effect is there, but it seems to be tough to get a scientific explanation for that ...

But you could be on the right track: the more a board sinks in, the more the centerpoint of the lateral plan (combination of the side of the board being in water and the fin area) will move towards the front of the board - and that might lead to the described effect !?

@Screamer:


Have you ever felt you've put a sail too big on any board? What happens then and how do you know it's too big?

Well, I do that pretty often. What happens is, that it gets more tricky not to turn upwind and your stance have to be pretty uncomfortable. The risk to be catapulted is rising due to your stance.


You gain nothing in early planing, handling is horrible, you may even start to sink.

I would say: a 9.0m is too big for the S-Type 104 - right ?
But actually, I can and do go out with my 9.0 on that board, when I don't have my 69cm wide SL board by hand - and the 9.0 is a quite better performer in light winds than my 7.8m - even on the S-Type 104 !
It's not too comfortable - but I can manage that with 73 Kg. Try that with 100 Kg - and you are absolutely right: it's horrible !

But on the end, it's a question of definition: when I can go faster with a bigger sail, you might call it "not too big for me" ...


Heavier riders will experience this with smaller sails than you. There's simply way too much weight and bulk on a board to carry. No scientific explanation here, but tried and tested many times.

Exactly !!!
May be, it's all about, how deep the board will sink in ... ?


Cheers Jogi
_________________
Who stops getting better, has stopped being good. (Philip Rosenthal)

Screamer
9th October 2008, 11:16 PM
I have a 95kg mate, he is an experienced racer. I've seen him use 11m sail on a 105lit hyper, 8.8 sail on an old, narrow 95lit Thommen slalom, and four-cam 6.7 North Warp on an 87lit Kombat (I've tried some of these combos). All this was for fun of course, well- to overpowered, and I'm sure there was no gain in early planing, while the handling was terrible (sinking up to his crotch in lulls). He was also much faster with appropriately sized rig (for the conditions/boards).
Not recommended under any circumstances.

I'm very much surprised sType105 is usable at all under a 9m. I thought for most people it's a 6-7m board.

jogi1111
10th October 2008, 02:48 AM
I'm very much surprised sType105 is usable at all under a 9m. I thought for most people it's a 6-7m board.

The official sailrange for the S-Type 104 goes from 4.5 to 6.8m. I personally love it most with a 6.5 race sail, and often I run it with 5.7 to 7.8m. I'm using GPS - and good powered up, the 7.8 runs faster on the S-Type than on my 69cm wide Slalomboard :)

For the recommended 4.5m sail (=lower sailrange limit), I would never use my S-Type 104: I would go down to 86 Liters or less. I guess, it's all a question of the riders weight.

Okay - the 9.0 is not my regular sail for this S-Type; especially for unsteady conditions, my wider SL board does it much better. But you can go out with the S-Type 104 and 9.0m to chase your GPS records, circle your race gybes and have fun - beginners and heavy weights excluded. Upwind abillities - who cares ? I always come back, where I started from.

Anyone out there, who could explain the effect...
...that lighter sailors do have a different sailrange than heavier ones - on the same board :eek:

... or at least other sailors, who can realize this effect at themselves.


Cheers Jogi
_________________
Who stops getting better, has stopped being good. (Philip Rosenthal)

kvda
10th October 2008, 01:15 PM
For me at 85 kgs, the isonic 125 can pretty well be sailed with 9.8, but the difference in planing abilities compared with my RS Slalom 8.4 is small- if even existing. So I prefer the 8.4 even in the lightest winds.

I did own the s-type 104 and wasn't able to manage bigger than 7.2 on this board, 7.8 was to big and 9.0 ... ough. But smaller than a 5.4 didn't work for me, the board got bumpy. In fact, my futura 101 handles bigger sails (RS4 7.8 on F101 is great) AND smaller sails better than the s-type 104.
So apart from the weight stuff, preferences, surfspot and personal style is a big issue.

jogi1111
10th October 2008, 03:23 PM
So apart from the weight stuff, preferences, surfspot and personal style is a big issue.

You are right - and that's the problem:
The weight effect for the sailrange is there, but it's hard to say, how big it is, as many other things like experience, sailing technic, outline and volume of the board and all what you mentioned above will also affect the sailrange.

As far as I could learned here, the influence of the sailors weight might be best ascribed by two factors:
1.) The more excess volume a board have, the more stable it is (if all other things are equal). If you are light weighted, the same board is more stable to you, than for a heavier surfer. You will be able to tilt the sail further to the nose to keep the board from turning into the wind, the heavier one might sink in, while pushing more weight onto the bow of the board. So - a light weighted could handle bigger sails easier, 'cause the board is much more stable for him.
2.) When a board sinks in more due to the heavier weight of the sailor, the lateral plan of the combination "side of the board in water plus fin area" move forward. This leads to the need to tilt the sail even further to the bow of the board, than light weights have to do (to get a trimmed board).

Both factors make it easier for lighter people to ride too big sails on a specific board. Is it worth to do so ? For me, I would say: Yes, as on really light winds, I could manage to come in plane earlier with a too big sail !


Cheers Jogi
_________________
Who stops getting better, has stopped being good. (Philip Rosenthal)

mim
10th October 2008, 04:59 PM
I am sorry but for you you seem to be the kind of guy having his opinion and not listening what the other peaople are trying to tell you.

I am not a leightweight but i really have to say that to combine the right board with an appropriate sail size is much better idea than trying to convince that 9qm is good on 100liters.

I have the feeling on my boards that the best suitable sailsize for the board is somewhere in 2/3 of the reange, that's when I feel really comfortable. I fact in light wind you probably have a bigger fin on your board to get you on a plane quickly, but it makes the board really unstable when speeded up.

Use your boards with whatever sail you want and we all will sailing with rigth combos.

Ciao Michal.
-------------------------------------------------------------------
Enjoy the wind when it is there...thats not exactly my case right now.

Per
11th October 2008, 12:13 AM
Interesting points and thoughts.
I'm 95 kgs (+100 dressed up). On my S-type 115 I could quite easily carry a 4.7 wave sail in close to 30 knots of wind and have fun. Few 65 kg sailors would find that combo useable. The board would simply get airborne due to their less weight. Anyway they could be comfortably on 80 litre boards and 4.0 sails and still have more reserve buoyancy.
I once tried my old Carve 145 with a 10.4 race sail (recommended max 9.0) and compared to my 9.4 sail I gained absolutely nothing but poor balance. The big question is wether a 65 kg guy would find that combo more useable than I did. I see no reason why he should. Actually my experience is that the recommended ranges for most boards are quite precise. We can move outside them (I read kevin Prichard telling he had a good result once with a 10.0 sail on a 97 litre slalom board!!), but I really don't belive that we, big or small get something really good from it, though it may be possible.

jogi1111
11th October 2008, 01:08 AM
I am not a leightweight but i really have to say that to combine the right board with an appropriate sail size is much better idea than trying to convince that 9qm is good on 100liters.


Hi Michael,

you got me totally wrong. I do not try to say, that it's best to go out with a too big sail on a too small board. No question: the appropriate sail on the appropriate board with an appropriate fin - that's best, no question :)

All what I like to discuss is the affect, that the sailors weight does have an influence on the sailrange of a board.

Why do I like to discuss that (and find a proper scientific explanation for it) ?

I think, people should know, that their weight (and of course their ability to sail, the spot, the type of sail and so on; see above) do have an influence on the sailrange of a board.

I often can hear people complain, that they were fooled by the manufacturer, 'cause the sailrange he promised, could not be sailed. Mostly it's about the biggest sail of the sailrange and the surfer is of heavy weight or a light surfer, having trouble, using the smallest recommended sail. Big surprise ?

Did you get, what I mean ?


Use your boards with whatever sail you want and we all will sailing with rigth combos.

I've 13 boards and even more sails here - and be sure, most of the time, I have the perfect fitted combo out there sailing ;)


I'm 95 kgs (+100 dressed up). On my S-type 115 I could quite easily carry a 4.7 wave sail in close to 30 knots of wind and have fun. Few 65 kg sailors would find that combo useable. The board would simply get airborne due to their less weight.

Exactly - that's it !!!!!


Cheers Jogi
_________________
Who stops getting better, has stopped being good. (Philip Rosenthal)

mim
11th October 2008, 02:27 AM
Hi Jogi,

no offence, from time to time there are threads from peaple that put here some kind of statement and are not open for discusion at all.

What I have to say to this topic:
I would reformulate what you say...lighter peaople are able to maintain smaller boards in light wind close to the planning treashold. It means even if you take 9sqm or more on 100liters board you can handle it...but it is not connected to the actual size/max recommended size ratio. It is more the weight to board volume ratio.

You are probably talking about the light wind...on the other hand...at a high wind, overpowered condition (letīs say with the biggest recommended sail) a heavy guy (100+kg) will be better on the same board than you...able to manage the sail size in the strong wind and control the board better , you be faster on plane probably but finally on the max speed he will beat you.

I just wanted to say this.
For me this discusion is meaningless, becasue:

1. if you have a bigger board as an option it is always better to get a board and sail, that fit somewhere in the middle of the sail range for the current wind condition.

2. if you have not such a board or the wind is too light you will be fighting anyway, whatever combo you will take.

Sorry I just do not see the point.
But at least it is nice to talk about the gear, setup etc...
Have fun,
ciao Michal.

jogi1111
11th October 2008, 04:13 AM
Hi Michael,


it is always better to get a board and sail, that fit somewhere in the middle of the sail range

Absolutely accurate !

But what is the sail range of a board ?
If you are average weighted, you just have to take a look at the catalog :)
But the others ... ? They should read this discussion first ;)


Sorry I just do not see the point.

Let's have an example: (Sail range data from 2007)
S-Type 104 => 4.5 ... 6.5m => middle: 5.5m
S-Type 115 => 4.8 ... 7.2m => middle: 6.0m
S-Type 126 => 5.0 ... 8.0m => middle: 6.5m

Let's say, I have a perfect board for my 9.0 and I have a perfect one for my 7.5, but I need a board,
what will fit perfectly for my 6.0m sail. I like to take an S-Type, but which one ?

If I would have 80...85 kg, I should take the S-Type 115, as it fits best: middle recommended sail is 6.0m - perfect !

But having this discussion in mind, people with 70 kg (100kg) might now be more aware: they take the S-Type 104 (the ST126 for 100kg), as they know, that their weight have an influence on the sail range of a board - and they both will have more fun with it, than with the S-Type 115 - I'm sure about that :)
(Don't forget: both (70kg and 100kg) were going to get a board for a 6.0m sail - not just getting any board for their weight ! And without this discussion, both would have thought, the S-Type 115 would be perfekt for the 6.0m sail ...)

That's the point; not more, not less !


But at least it is nice to talk about the gear, setup etc...

Especially, when waiting for wind ...


Cheers Jogi
_________________
Who stops getting better, has stopped being good. (Philip Rosenthal)

P.S.: At the end, all three (70, 85 and 100kg) will (more or less) recognize the same perfect sail range for their 6.0m sail of 4.8...7.2m, but in 3 different boards !!!

mim
11th October 2008, 04:49 AM
Hi again...this is getting almost academical but I kind of like it.

You concetrate yourself on a same sail size. But to me it is more reasonable to take the wind and fix it.
And now speeking from my own experience, I would pick the board where I would get like 15% below the max recommended sail to be overpowered...as a 100kg guy (appropriate combo)...accordingly to your weight you get a smaller sail and be the same way overpowered and now to the board...I would rather go for a smaller volume on to get better speed once planning (radical jibing, easy chop handling and so on...)

From your example...
let me say:

115 and 6.1 and I would be slightly overpowered (ideal condition to my experience)...
if you want to be powered in the same way you will be good on with smth like 5.6 at yours 70kg.

As far as the wind is enough to get me planning I can handle bigger sails easier than you...because once plannnig you let all your weight to be caried by the sail and you can handle more power....see the speedsurfers...they are not exactly lightweights.

Ciao Michal.

What I am trying to say...if you have to go above the sail range (what ever your weight is) the ride will not make as much fun...and in fact you can say that as a lighter surfer you can handle a bigger sails tham max reccomended.
But this only is right when the havier one does not have the techique to get himself plannig (this would be probably my case...but I have enough dimensionalysed boards to get comfortable with a bigger sail size).

Floyd
14th October 2008, 06:05 PM
Hi
Apologies it looks like I`ve tried to hijack this thread.I posted my question before seeing this.
Anyway original poster has got a very good point.
Kode 86 is quoted as sail range 4.0 to 6.0. Dont think I could "sensibly" use it with a 6. (Struggle on my Evo 92 with a 6 or to be more accurate its obvious I would be better on a bigger board.)
The kode 102 is quoted 5.0 to 7.5. Two things a)It was fine with 4.5 (with my not incoonsiderable bulk) but I would not use it ith 7.5 !
My evo works down to 4 metre but is not "ideal" with a 6. I use it well out of range.(I`d guess 3.7 to 5.4 ish)
Could lead to heavies buying wrong kit or more serously from SB`s point of view missing an "ideal" sale.
Heavier mate (108k) specifacally bought k105 for sub 5metre days.Works great for him.
Daughter (67k) goes great on Evo 92 with 6.5 !

Seems to me heavier riders decrease both upper and lower limits of a board but its range stays pretty constant. (approx 2 metre range generally on wave/high wind kit)
Lighter sailors increase both.(but again range is pretty similar)

This should be pointed out in specfication.(But it takes some explaining ?)

Ola_H
14th October 2008, 07:32 PM
I answered in the other thread, but to summarize: Yes, sail range depend on sailor weight, but other variables are just as important. So it takes two very similar persons sailing similar sails in similar waters in similar ways, bot one being heavier than the other for a comparison to make sense. And different people might even have differnt reasons to change boards size at all. For example, with my wave boards, I more choose boards depending on the wave conditions. Pretty much all my boards go with pretty much all my wave sails. Might choose 70 liter with a 5.5 if waves are good, but might sail an 80 liter with a 4.0 if its B&J conditions.

I think this particular thread clearly shows how much personal preference can shift things around. At least with a bit of experience, you genreally know what kind of size you like. And of you don't, I think it is a much safer bet to just ask someone more experienced, for example on this forum, than try to read some complicated schemata of sails, boards, weights, conditions, skills etc etc.

Jean-Marc
18th October 2008, 05:50 PM
Floyd,

I agree the sail range of a given board depends on rider's weight but I don't agree figures given by Starboard were wrong.

By reviewing all of my recorded sessions since 2003, I'm using all of my boards most of the time with the largest sail simply because excess volume is just unecessary ballast for my 65 kg light weight :
- Serenity: 100% TOW with 11 m2 sail (2-7 kts wind range);
- HS105 : 70% TOW with 11 m2 sail; 30% TOW with 8.2 m2 sail (7-15 kts wind range);
- Kombat 86 : 90% TOW with 6.9 m2 sail; 10% TOW with 6.2 m2 sail (12-20 kts wind range)
- Acid 62 : 60% TOW with 5.4 m2 sail; 40% TOW shared between 4.7/4.2/3.6/3.3 m2 sails (20-45 kts wind range).

Please, pay attention that recommended sails given by Starboard for all the boards listed above were in fact much smaller : 10 m2; 9.5m2; 6.0 m2; 4.7 m2 respectively. What obviously is efficient for a 65 kg light weight rider is not for a XXXL rider, except the Serenity + 11 m2 sail combo which is still great for a 105 kg rider. Buoyancy is a key limiting factor with 105 kg...

A one-size-fits-all solution does not exist IMHO, see your 67 kg daughter on Evo 92 + 6.5 m2 sail combo. Once again, there are so many variable at play that the best piece of advice we can give is to ask your question on our forums. Somebody your size and skills might have the answer already to be shared with you according to YOUR needs.

Cheers !

JM

Floyd
22nd October 2008, 01:20 AM
Hi Jean-Marc
Dont think I said they were wrong ;I said they were wrong for some riders.
Quoting instances of sailors using boards within guidelines does not prove they are correct for all.In reality only one instance of use outside "range" indicates they are not perfect.(I know no-one has claimed this)
I use Evo 92 out of range.My mate uses (and bought) k105 out of range virtually all time.
Just think there should be some mention (for us heavies) that we can use most boards with under recommended ail size.
(Or an attempt to quantify it)
Take care.