Gboots said..
Another query re volume weight ratios. Does this apply equally to long boarding SUPs ?
Eg a Style, Nalu , Stylemaster ?
i would assume it's a totally different equation as the lower width and longer length reduce any corky effect particularly if rails are refined

In my experience, that's the same thing.

But of course the longboard shape is stabler with the length adding to the effectiveness of the width (the sum of all the widths is greater), and the rails being more parallel than a pulled-in shortboard shape. Rideable volumes can thus be compared to the shorter Tomo shapes.

A low volume longSUP is really enjoyable in my opinion. You still get the glide of the length, but the thin rails make wonder when the conditions get better. The drawback is in very small, weak waves.

I've been riding sups now for about three years and have gone from
180L
170L
148L
130L
125L
121L
110L

My weight has probably gone down from 90kg - 85kg in that time and I've been trying to progress so I can kind of ride like I used to ride a short board (the memory is very distant and hazy from about twenty five years ago when I stopped riding a board due to busyness, 4 kids & injury)

Obviously board shape makes such a huge difference to stability rather than just litres ie stubby square nose and parallel rails v pointy nose and rocker. But man it's incredible fun experimenting. I went out this morning after not surfing for a few days (I had to go to Melbourne for work) when I got out the back with some cross chop and swell bumps and a wetsuit, it was much more of a struggle than glassy smooth surf and just boardshoarts. One tip though: I've found balancing on a bosu ball in the gym in between surfs really helpful when I get back out.
PS I'm currently riding a Jimmy Lewis Worldwide 8'1" and loving life. And I'm eyeing the 107L Barra in the video above.... have fun experimenting!

Well last few weeks I have tried a few of my boards in different types of waves. All sub 3 foot waves.

I have a love hate relationship with my 88 Speeed. I had two days of pure bliss. 300-400m rides in river mouth peelers 1-2ft max.
Took it out in beach break in 3ft faces at near low tide. The board just flies and kept getting thrown off back. Not fun.

So the 88 Speed is about 1.75 - 1.90 vol to weight ratio ....so yes it is big .

This has me thinking . Is SUP better suited to larger people ? Stupid question ?
Maybe but I'll explain why I ask.

The lighter you are the smaller the board should be for a surf SUP (let's assume a 1.3 weight to vol ratio).
This means less glide .
If you are 45kg a good board for surfing based on say a 1.3 ratio would be around 60L. There are not too many 60L boards which will give you good glide that are sufficiently wide . So as you get lighter it gets harder to keep the glide .
A 90kg rider could ride my 88Speeed and it would still have a good outline and length for glide .

The shorter the board the more work to catch waves and the more you need to be close to the pocket which takes away the advantage of SUP in the first place .

Is my logic flawed ? Particularly for the average SUPer . I have excluded freaks like Kai Lenny and so forth from my thinking .

Gboots said..
Well last few weeks I have tried a few of my boards in different types of waves. All sub 3 foot waves.

I have a love hate relationship with my 88 Speeed. I had two days of pure bliss. 300-400m rides in river mouth peelers 1-2ft max.
Took it out in beach break in 3ft faces at near low tide. The board just flies and kept getting thrown off back. Not fun.

So the 88 Speed is about 1.75 - 1.90 vol to weight ratio ....so yes it is big .

This has me thinking . Is SUP better suited to larger people ? Stupid question ?
Maybe but I'll explain why I ask.

The lighter you are the smaller the board should be for a surf SUP (let's assume a 1.3 weight to vol ratio).
This means less glide .
If you are 45kg a good board for surfing based on say a 1.3 ratio would be around 60L. There are not too many 60L boards which will give you good glide that are sufficiently wide . So as you get lighter it gets harder to keep the glide .
A 90kg rider could ride my 88Speeed and it would still have a good outline and length for glide .

The shorter the board the more work to catch waves and the more you need to be close to the pocket which takes away the advantage of SUP in the first place .

Is my logic flawed ? Particularly for the average SUPer . I have excluded freaks like Kai Lenny and so forth from my thinking .

It's like this, a 198 liters 11' x 31" longboard is one of my funnest boards to ride. But I can use 6' and 95 kg to get on the tail and turn it real tight, a smaller surfer will not have as much fun with this much volume.

With the excess volume I'm mobile enough to paddle or surf to a good steep spot on the wave, and takeoff.

Or if sharing with other surfers, hang on the inside and harvest a scrap on every set for as long as you can.
Most days though the 120 liter board is what I grab.

Go as small as you can still paddling slowly trolling for wave out the back. I am 75-77kg and ride a 87L 7'10 27 Ecs weapon which is shaped similar to a short board, with lots of concave. It's just as easy to paddle onto a wave due to the concave and flat rocker. It goes so much faster and better on a wave then all of my bigger SUP's with more liters eg 8' Pro Vex 116 liter, 7'2 bambam 116 liters, Evoke 8'3 130L, even in small knee high weak surf. Basically to keep balance I have to slowly paddle around in cycles but its great fitness and can easily do this for a usual 1.5 hour surf, or longer if I have more time. I have ridden a 77L 7'4 fanatic but found the effort to keep it on top of the water was to much effort. So at your weight of 72 kg go for something between 84 and 95 Liters, thats if you plan to SUP surf alot, because paddle technique keeps you balanced. A bigger board is just to corky on a wave and doesn't give that much better balance.

Wouldn't mind knowing what people's thoughts are on height vs volume as well or I just need to get over being 6,2 and excuses haha. I guess the width of the board as you go higher makes a big difference. I still like being under 30inch boards even if it's hard haha.

Brenno said..

Frothn said..
Wouldn't mind knowing what people's thoughts are on height vs volume as well or I just need to get over being 6,2 and excuses haha. I guess the width of the board as you go higher makes a big difference. I still like being under 30inch boards even if it's hard haha.

Good question.
Currently putting some ideas together for a 10 footer.......yep, again
I started out around 5 years ago on a 10'10" 201 litre monster. I was around 108kg, and a novice SUPper. I know I scared the crap out of a few people (including myself) with this landing barge/aircraft carrier in the surf. Oops
I dropped to 160 litres, then down to 140 litres, and now at around 98kg I'm comfortable at 130 litres, and enjoying the surf a whole lot more (and smiling more).
One thing that hasn't changed is my height, and at 6'2" my centre of balance is obviously higher than some.
130 litres is my "wall" for volume, and 30" is my "wall" for width on a shorty shaped SUP. I have gauged my "wall" using many 2 to 3 hour SUP surf sessions.
I have found I can go down to 29" for longer and square shaped SUPs, but found that pushing a 130 litre longboard shaped SUP through the water is hard bloody work.
Thoughts on whether I should go up to 135 or even 140 litres, and does construction have a big part to play?

I mostly ride a 10'4" x 28.5" @ 140L, Sunova longboard sup... at about 108kg. As long as the rails are right, there is nothing wrong in having a little extra float in a longboard shape IMO.

The lowest Sunova i've had was 126L. 8'2" Skate XL. Floated fine, didn't like how it surfed. Also had a Creek 9' x 30.75" x 129L. Float was about perfect.

However, a mate of mine has a Naish Nalu Carbon 10' - which says 130L, however the water line was above my ankle when standing on it...

From trying out other brands of boards also, I feel Sunova's actually float more than the volume states (must be because of the Balsa) - so in effect you could go slightly lower in volume to compensate.

funny thing is the Naish is lighter than my sunova's...

Gboots said..
That surprises me Hoppo. Didn't realise that . Now that does make it interesting

Hmmmmm, I wonder, do all these shapers calculate their volumes using the same means and methods?
And how accurate are the results?
Oh oh, is this a can of worms?

Brenno said..
Hmmmmm, I wonder, do all these shapers calculate their volumes using the same means and methods?

Most of them just use the amount given by their CAD software. Normally it should be quite close to the actual volume of the blank... if the CAD author took the effort to properly compute it, which I doubt, seeing that the computation is instantaneous. From what I read from surfboard shapers, it can be 10 to 20% off in practice, which is huge, and differ between the software used. Then the back shaping shaves off some volume, and the glassing adds some (especially with sandwich boards).

And if the shaper dows not use CAD, but use hand-shaped prototypes as models... volume is just a wild guess :-)

Yes Colas, CAD program computes the volume automatically and more than that it is able to compute a final volume once the board design. For instance the board I'm showing here can be computed quickly in a 30 liters 6' 19'' shortboard for my son.
Brenno, should be the extra 5 liters you find out on your board comes from the forgotten parameter of thickness and therefore the final volume of the lamination or tuff skin of your board.
Designing SUP on CAD program as Shape3D allow to give the accurate volume distribution which is so important for the best stand up paddling balance without compromise of an extra volume.
But a good choice of extra volume can still do a comfortable and rippable board like Scott or Bert and others are doing.

For instance, the board I've drawn for my own use, I have a minimum but still comfortable dims is the best volume distribution with the best shape I can draw. Please look on the diagram of the volume repartition below here and see how even are the quarter volumes on my board. 14,3% 35,8% 35,6% 14,2% . This volume repartition is the most stable it can be and doesn't need extra volume to paddle into the waves. So with 90 liters to my 78 Kg body and a light built board 6.5 kg, I may have a reliable volume for some frothing take off and bottom turns! An extra volume would be a pain ripping the curl of waves.

Look at this beauty, so proud of this design. Agung will let me surf it in Bali in September for sure!
www.shape3d.com/Viewers/Viewer3D.aspx?Account=6301&BoardName=KANOLINE

colas said..

Kami said..
Yes Colas, CAD program computes the volume automatically and more than that it is able to compute a final volume once the board design.

Yes, but how do they compute it? The math for it seems non-trivial, so I guess it is interpolated with samples. Basically this seems a non-trivial math problem, (computing the volume of splines), something I dont trust most programmers on.

By searching for a formula, I for instance stumbled upon a paper describing somesoftware that scanned tree trunks, and modeled them with splines... the final computed volume could be 60% off.

I'm just an applier of this program but can say that:
The 3 dimensions of the surfboard are made from splines which are primarily circle shortcuts, next step of these circles in a 3D volume is the sphere... Once that said the program applies the trigonometric rules of the circle in each dimension or radius of each circle to the final sphere which is the board itself ... So once the board is designed just open or close the radius of the virtual compass to design a longer or wider radius spline and therefore the different templates of the actual board (I mean outline and foil or rail curves). The virtual compass is the computer.
Shape3D has geometric functionalities which make shaping a scientific art now
Here a video showing how to compute different volume from an original shaping file. Hope both my explanation and English speaking are understandable.

Kami said..
splines which are primarily circle shortcuts

No, they aren't. They are polynomial functions, much more complex to give you the smoothness impossible with assembling sphere parts.


PS: I wrote a "shaping" software when I was a student (nearly 40 years ago), it was 2D and printing on paper, there was not yet graphics CRTs available at the time :-) I would print out the templates at full scale, taping the paper sheets together. Alas my lack of shaping skills made me not continue this effort :-)

colas said..

Kami said..
splines which are primarily circle shortcuts

No, they aren't. They are polynomial functions, much more complex to give you the smoothness impossible with assembling sphere parts.


PS: I wrote a "shaping" software when I was a student (nearly 40 years ago), it was 2D and printing on paper, there was not yet graphics CRTs available at the time :-) I would print out the templates at full scale, taping the paper sheets together. Alas my lack of shaping skills made me not continue this effort :-)

Yes, you are right, Colas this is not shortcuts circle or circle sector They are derivative functions. I tried to make that explanation the simplest I can because, you know, there is not anymore dunce at school because they are all gone surfing

From 95 I used 2D program. It was so nice to print spline and therefore to get the right template in the shaping room. The circle sectors of different radius been used since 80 and before 95 to draw the template on plywood.


Back to the topic, I Just explain how you can adjust your own volume from a perfectly balanced board volume using CAD program.

cantSUPenough said..

MattBailey said..
well I'm 97Kg, when i was 100-102 rode my Fanatic Prowave at 104L. Fortnight ago i thought i'd see how far i could push it and bought a cheap-ie JP pro 7'4 X 27 @90 litres. Whilst i cant really wait around out the back all day (if I cannot see something immediately when getting out the back, I just sit down on the board and wait), I rarely miss a wave when they come through. BUT MAN does it surf....

So board is 6Kg (with fins, tail pad, wax and leggy - not bad), I'd be say 98 wet plus paddle on 90l, puts me around 0.87 factor.

Its certainly not easy, but its certainly not impossible. Back to the topic at hand - its all about what you want from your surfing... I think there's so much talk about weight Plus 'X' (like no less than 1.2) that a lot of people don't think its possible and therefore don't show the lower volume the patience they need to actually get used to it... because it certainly takes some time, you just need the desire to see it through.

Impressive! Is that in lumpy conditions or perfect? My smallest board is 106L and I am 94 kg (plus board, plus wettie, etc.) but I need very good conditions. I normally ride 115L instead. On my recent surf trip, two guys had very small boards - they were younger and were much more highly skilled, so it is not fair to compare - but they mostly sat out the back until the right wave came.

i tend not too be too troubled by chop, but refraction / rebounds / backwash and especially currents seem to be the main determining factor as to how hard a time I'm going to have. I think my point is more that its all possible (seen that video of Ty from Blueplanet, hes 74KG + board... and hes riding 63Litrs, its like .78 or something) You just have to understand what you want from your surfing and then simply stick it out.

My brother for example has no intention of following my path to low volume, he'll surf like 1.25+ and any surf needing something smaller (ie its really good) he just pulls out his normal prone board (which is kinda logical)...