Forums > Surfing Longboarding

Twin on midlength.

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Created by WindNoob > 9 months ago, 10 Sep 2019
Cuttlefish
QLD, 1332 posts
4 Feb 2020 3:49PM
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Hydromann said..

Cuttlefish said..
These would be better for your carbon jet. Run them as a twin or twin with either a centre trailer or with small trailers in the quad plugs.
They will have less flex than the Modii's and a more area in the tips.
www.gumtree.com.au/s-ad/burleigh-heads/surfing/surfboard-fins-akila-aipa-twin-fins-fcs/1235082334
Trailers for sale here:
www.sanctumsurf.com.au/stablizer-fcs




These look interesting....

Not twins as such but maybe a nice option for rears in a quad?

www.gumtree.com.au/s-ad/grafton/surfing/fcs-fins-with-venturi-channels-and-winglets/1228665911

Reminds me of Roy Stuart's fin designs www.roystuart.biz/ mixed with some Fin Sciences design concepts finsciences.com/surfboard-fin-science/

Fin sciences is interesting, he uses a lot of "tech" talk to try and explain why "modern" wing design is better than bio-mimicry, but what he fails to recognise or tell people is that modern solutions where developed to deal with modern supersonic problems. From a sub sonic perspective the difference in velocity and the loss based on tip turbulence is negligible. 90% of surfboard fins etc are simply not going fast enough for tip velocity to make such a significant difference to 85% of surfers who will never notice.

The bigger performance compromise would be to do with stall, the angle at which a wing looses it lift capacity. For a fin this would be the angle at which the fin breaks hold of the water and shears.

That's where Roy's messing about with tubercles on leading edges is interesting, whilst he has a very limited scientific understanding he has an amazing intuitive comprehension, that is the ability of the brain to envisage dynamic concepts and interactions.

The tubercles break the laminar flow into a mix of smaller pockets of turbulent and laminar flow streams. This naturally causes a slight drag loss but overcomes the stall issues of the wing. Without them a humpback would not be able to make the tight turns it needs to in order to round up and catch it's food. It would stall through a turn and shear until it corrected the attack angle.

The venturi channel fins whilst not exactly tubercles would essentially have a similar effect, but they would also have the effect of creating higher lift for the foil shape due to greater drag over the longer surface.

And then there's the latest fins from Cheyne Horan which have some merrit as well www.cheynehoran.com.au/fins/

If you took the shape of Cheyne's fins and designed in the venturi channels and winglet then I think that would be an optimised fin design.

For my two cents worth I think the future of surfing will be found in fin design and placement, FCS, Futures and others have done some great work on fitment systems, composite materials for flex control etc. But I think you will see them experiment more with some of the concepts that Roy has pioneered.

And shapers will have a whole new field of designs to consider the dynamic effect of in the whole of the surfboard design.


My brain hurts.
Oh and careful speaking he "who should not be named" name out loud lest he re-visit all the different forums with spam posts.

Hydromann
626 posts
4 Feb 2020 5:30PM
Thumbs Up

Select to expand quote
Cuttlefish said..

Hydromann said..


Cuttlefish said..
These would be better for your carbon jet. Run them as a twin or twin with either a centre trailer or with small trailers in the quad plugs.
They will have less flex than the Modii's and a more area in the tips.
www.gumtree.com.au/s-ad/burleigh-heads/surfing/surfboard-fins-akila-aipa-twin-fins-fcs/1235082334
Trailers for sale here:
www.sanctumsurf.com.au/stablizer-fcs





These look interesting....

Not twins as such but maybe a nice option for rears in a quad?

www.gumtree.com.au/s-ad/grafton/surfing/fcs-fins-with-venturi-channels-and-winglets/1228665911

Reminds me of Roy Stuart's fin designs www.roystuart.biz/ mixed with some Fin Sciences design concepts finsciences.com/surfboard-fin-science/

Fin sciences is interesting, he uses a lot of "tech" talk to try and explain why "modern" wing design is better than bio-mimicry, but what he fails to recognise or tell people is that modern solutions where developed to deal with modern supersonic problems. From a sub sonic perspective the difference in velocity and the loss based on tip turbulence is negligible. 90% of surfboard fins etc are simply not going fast enough for tip velocity to make such a significant difference to 85% of surfers who will never notice.

The bigger performance compromise would be to do with stall, the angle at which a wing looses it lift capacity. For a fin this would be the angle at which the fin breaks hold of the water and shears.

That's where Roy's messing about with tubercles on leading edges is interesting, whilst he has a very limited scientific understanding he has an amazing intuitive comprehension, that is the ability of the brain to envisage dynamic concepts and interactions.

The tubercles break the laminar flow into a mix of smaller pockets of turbulent and laminar flow streams. This naturally causes a slight drag loss but overcomes the stall issues of the wing. Without them a humpback would not be able to make the tight turns it needs to in order to round up and catch it's food. It would stall through a turn and shear until it corrected the attack angle.

The venturi channel fins whilst not exactly tubercles would essentially have a similar effect, but they would also have the effect of creating higher lift for the foil shape due to greater drag over the longer surface.

And then there's the latest fins from Cheyne Horan which have some merrit as well www.cheynehoran.com.au/fins/

If you took the shape of Cheyne's fins and designed in the venturi channels and winglet then I think that would be an optimised fin design.

For my two cents worth I think the future of surfing will be found in fin design and placement, FCS, Futures and others have done some great work on fitment systems, composite materials for flex control etc. But I think you will see them experiment more with some of the concepts that Roy has pioneered.

And shapers will have a whole new field of designs to consider the dynamic effect of in the whole of the surfboard design.



My brain hurts.
Oh and careful speaking he "who should not be named" name out loud lest he re-visit all the different forums with spam posts.


Hahaha, gotcha.

Yeah fins and board designs do that to the old grey matter hey.

Hydromann
626 posts
4 Feb 2020 5:34PM
Thumbs Up

Select to expand quote
Cuttlefish said..

Hydromann said..



Cuttlefish said..
These would be better for your carbon jet. Run them as a twin or twin with either a centre trailer or with small trailers in the quad plugs.
They will have less flex than the Modii's and a more area in the tips.
www.gumtree.com.au/s-ad/burleigh-heads/surfing/surfboard-fins-akila-aipa-twin-fins-fcs/1235082334
Trailers for sale here:
www.sanctumsurf.com.au/stablizer-fcs





Thanks Cfish, looked at those. Something of a gimmick I recon.

Dimples do change the surface contact flow from laminar to turbulent. Which would help with stall angle but only when the flow is generally uniformed around the object with sufficient velocity. That never quite happens with a surfboard, there are too many disruptors of the laminar flow stream, non uniformed velocity, turbulence, aeration etc. All of which affects the surface tension and laminar flow.

For the most part I think the flex in a fin, its size and placement would be much more noticeable than the effects of surface flow.

I'm keen to try the Soars, but only have a budget for the MODII unless I can find similar used.

Also like the idea of fibreglass over a injection moulded. I can easily refoil the MODII if I don't like them back to a Soar shape. Can also stiffen them up a little with a layer of carbon fibre if needed. All fairly easy to do.




The Soars and the Modiis side by side. Cant see how it would be simple to re-template a Modii into a Soar.
Dimples on the 3D fins I'm not even thinking about more the positive of the Akila Aipa template in fibreglass for a budget price.







You're a legend dude. I can easily narrow it and refoil if I want more flex in the modii, but you alrady said they were quite flexy so may not need to.

Rabbs
251 posts
4 Feb 2020 7:20PM
Thumbs Up

No offence Hydro....

You seem to contradict yourself regarding the importance of a smart shaper.
One post your bagging them , next your praising them for their intuitive skills to design a
board for the punters needs.

I trust my shapers fin choice because he surfs way better than me, ....in all conditions, and if his boards don't work...no sales.

Hydromann
626 posts
5 Feb 2020 8:18AM
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Select to expand quote
Rabbs said..
No offence Hydro....

You seem to contradict yourself regarding the importance of a smart shaper.
One post your bagging them , next your praising them for their intuitive skills to design a
board for the punters needs.

I trust my shapers fin choice because he surfs way better than me, ....in all conditions, and if his boards don't work...no sales.


No offence taken and thanks for calling me on that perspective.

I don't mean to bag any good shapers skills. It's a trade that they have developed over time. A lot of which is not scientifically defined or even fully understood. My hats off to them.

But I do bag out a crap attitude and victim mentality. Instead of bitching about the death of the industry, popouts pricing, crap designs etc. Without any evidence other than their own personal bias do something about it.

Instead of all trying to be boutique local legend designers and shapers form a unified collective and educate about the advantages of twice the price custom design solutions for novice and beginner surfers?

Oh hang on there is next to zero advantage for a beginner to be riding a custom shape.

The pop out board market targets beginners or people who can not afford customs. It draws people into the sport by lowering the barriers to entry. And any shaper that can not see this and who is pissy about loosing business is either short sighted, or does not produce a reputable product. If they did produce a reputable product it would be targeted at a different market to the pop outs.

My hat is off to any shaper that produces reputable product. This type of skill set in taking seemingly vague lists of wants and desires and transforming that into a near living thing is born out of years of hard work. But means absolutely nothing to a person who does not appreciate it, it is lost on a learner. It's like trying to get a three year old to appreciate Shakespeare or classical music.

They are interested in overcoming entry barriers, not intricacies of design understanding.

And at some point in their surfing journey they will understand design features, they will appreciate those considerations when they can feel the difference it makes to their surfing.

And this then give custom shapers opportunity.

The only issue that custom shapers face now is the closing gap. That is how quickly solid design features are being refined into pop out designs, and the quality improvement.

For me I choose a board design that had what I considered a small gap. It has the size, volume, shape, and design features that I was looking for, and on top of that the ability for me to dial it's performance in to varying conditions with fin selections and experimentation.

So no, not bagging the skills or hard work of shapers. Just some of them have a sucky attitude towa ds change and opportunity.

If I was a pro shaper I would embrace the change. Hell I would source awesome core designs and sell them, build a newbie client base over time that as they improve and grow and can appreciate the finer elements of design I could then apply my skills to a solution for their needs.

Instead of lamenting the way things used to be and how unfair thing are now with a hatred and vengeance that destroys their souls.

Just saying...

Hydromann
626 posts
5 Feb 2020 8:50AM
Thumbs Up

"I trust my shapers fin choice because he surfs way better than me, ....in all conditions, and if his boards don't work...no sales."

Rabbs,

That's because your wants and needs exceed those of a look.

Your on the other side of kook and have a skill set and ability that demands more.

Hence your shaper needs to meet that expectation. Specific to your needs and desires for the level of your surfing and the conditions that you like.

And none of that takes away from the absolute fact that nearly 90 percent of what you want can be found in a core design, and even in a well designed pop out.

If it couldn't then why do shapers have their own core designs that they market?

For me, once I get dialled back in and define the combination of elements that work for me and have the coin. Then I will be going to Webber or Miller and dialling in a Diamond or a SubX. Which I would not have done if there was no pop out like the CJet that allowed me room to experiment and define what I like and don't like.

Hydromann
626 posts
5 Feb 2020 7:04PM
Thumbs Up

Has anyone considered Twinzer setups?

Macaha
QLD, 21900 posts
6 Feb 2020 12:36AM
Thumbs Up

Select to expand quote
Hydromann said..
Has anyone considered Twinzer setups?


Help me out here I'm a longboarder in a longboard forum, I understand this is 2020 am I missing something?

Ricardo1709
NSW, 1301 posts
6 Feb 2020 5:46AM
Thumbs Up

Select to expand quote
Hydromann said..

Rabbs said..
No offence Hydro....

You seem to contradict yourself regarding the importance of a smart shaper.
One post your bagging them , next your praising them for their intuitive skills to design a
board for the punters needs.

I trust my shapers fin choice because he surfs way better than me, ....in all conditions, and if his boards don't work...no sales.



No offence taken and thanks for calling me on that perspective.

I don't mean to bag any good shapers skills. It's a trade that they have developed over time. A lot of which is not scientifically defined or even fully understood. My hats off to them.

But I do bag out a crap attitude and victim mentality. Instead of bitching about the death of the industry, popouts pricing, crap designs etc. Without any evidence other than their own personal bias do something about it.

Instead of all trying to be boutique local legend designers and shapers form a unified collective and educate about the advantages of twice the price custom design solutions for novice and beginner surfers?

Oh hang on there is next to zero advantage for a beginner to be riding a custom shape.

The pop out board market targets beginners or people who can not afford customs. It draws people into the sport by lowering the barriers to entry. And any shaper that can not see this and who is pissy about loosing business is either short sighted, or does not produce a reputable product. If they did produce a reputable product it would be targeted at a different market to the pop outs.

My hat is off to any shaper that produces reputable product. This type of skill set in taking seemingly vague lists of wants and desires and transforming that into a near living thing is born out of years of hard work. But means absolutely nothing to a person who does not appreciate it, it is lost on a learner. It's like trying to get a three year old to appreciate Shakespeare or classical music.

They are interested in overcoming entry barriers, not intricacies of design understanding.

And at some point in their surfing journey they will understand design features, they will appreciate those considerations when they can feel the difference it makes to their surfing.

And this then give custom shapers opportunity.

The only issue that custom shapers face now is the closing gap. That is how quickly solid design features are being refined into pop out designs, and the quality improvement.

For me I choose a board design that had what I considered a small gap. It has the size, volume, shape, and design features that I was looking for, and on top of that the ability for me to dial it's performance in to varying conditions with fin selections and experimentation.

So no, not bagging the skills or hard work of shapers. Just some of them have a sucky attitude towa ds change and opportunity.

If I was a pro shaper I would embrace the change. Hell I would source awesome core designs and sell them, build a newbie client base over time that as they improve and grow and can appreciate the finer elements of design I could then apply my skills to a solution for their needs.

Instead of lamenting the way things used to be and how unfair thing are now with a hatred and vengeance that destroys their souls.

Just saying...


Please elaborate

Hydromann
626 posts
6 Feb 2020 7:43AM
Thumbs Up

Select to expand quote
Macaha said..


Hydromann said..
Has anyone considered Twinzer setups?




Help me out here I'm a longboarder in a longboard forum, I understand this is 2020 am I missing something?



I've been experimenting with fin layouts. My board has the option to be 2+1, quad, thruster, or twin fin.

I've loved riding quad, now trying twin quad, normal twins up front with smaller twin trailers like nubsters.

Twinzer are the reverse of this, larger twins at back with smaller fins at front. Seems from reading up that the proximity of overlap placement is what makes Twinzer work well.

Just wondering if anyone has used this on a mid length or mini Mal?

To try it on my board I just need to install a couple of FCS plugs. Was looking to do that anyway to trial a set of keels with 3 tabs.

Google Twinzer and you'll see what I'm thinking.

laceys lane
QLD, 19803 posts
6 Feb 2020 12:08PM
Thumbs Up

Select to expand quote
Hydromann said..
Has anyone considered Twinzer setups?


Im thinking about it on a shortboard ive ordered.Just a swap around of quads.
My shaper considers it good on the board im getting.

Im one those ancient guys that orders their boards from the shaper. Not the shop front sales guy.
Cant get my head around guys getting big money customs and they never speak to the shaper.

If you go custom at least speak to the guy shaping it

Hydromann
626 posts
6 Feb 2020 10:30AM
Thumbs Up

Select to expand quote
laceys lane said..


Hydromann said..
Has anyone considered Twinzer setups?




Im thinking about it on a shortboard ive ordered.Just a swap around of quads.
My shaper considers it good on the board im getting.

Im one those ancient guys that orders their boards from the shaper. Not the shop front sales guy.
Cant get my head around guys getting big money customs and they never speak to the shaper.

If you go custom at least speak to the guy shaping it



I didn't go custom, couldn't afford it or justify the added cost for my level of surfing. Coming back into it after 20 years I just needed something to suit the wish list I had that would allow some experimentation.

So I bought a 6'10" mid length with multi fin placement plugs.

The swap around of quads seems a little more complex depending on which shaper you listen to and their experience and technical knowledge.

Most state that you need to use dedicated design twin fins at the rear, not just the larger quads. And then use 2 x stabilisers like the Sanctum www.sanctumsurf.com.au/stablizer-fcs up front.

But then placement in relation to each other apparently comes into play due to slip streaming effects? Not entirely sure on that one as trailing fin does not follow the same flow lines as the leading one? But it seems that there is some form of hydrodynamic interaction between them, and for my two bobs worth as a fluid mechanics engineer I would hazard that it has more to do with fluid release in the cavity between the fins. Unlike a big triple tab keel fin which would present similar surface area to the 2 + 2 twinzer, the twinzer would allow pressure relief through the cavity between the fins. In simple terms it's called the path of least resistance, all energy conforms to this truth, pressure, flow, heat, sound etc. all want to find a steady state and return to it as efficiently as possible against the resistance that presents itself.

In this case the fins, confined within the form of the board shape and design. A very dynamic field of variables that even does my head in and I work with this stuff daily.

Still after a while you become intuitive, just like shapers with the designs that hey make. Intuitively over time, trail and error they become aware of what does and does not work. And between them and different designs you see a lot of synergy as their design features coalesce.

But fins, well up until recently they have remained reasonably unchanged in shape and features, and only now are conventional concepts and the mainstay of the thruster being challenged by new shapes as well as geometric and composite material design features, placements, combinations etc.

Resulting in people discovering just how much effect a set of fins and their design features can have on a boards performance.

laceys lane
QLD, 19803 posts
6 Feb 2020 1:15PM
Thumbs Up

Select to expand quote
Hydromann said..



laceys lane said..





Hydromann said..
Has anyone considered Twinzer setups?







Im thinking about it on a shortboard ive ordered.Just a swap around of quads.
My shaper considers it good on the board im getting.

Im one those ancient guys that orders their boards from the shaper. Not the shop front sales guy.
Cant get my head around guys getting big money customs and they never speak to the shaper.

If you go custom at least speak to the guy shaping it






I didn't go custom, couldn't afford it or justify the added cost for my level of surfing. Coming back into it after 20 years I just needed something to suit the wish list I had that would allow some experimentation.

So I bought a 6'10" mid length with multi fin placement plugs.

The swap around of quads seems a little more complex depending on which shaper you listen to and their experience and technical knowledge.

Most state that you need to use dedicated design twin fins at the rear, not just the larger quads. And then use 2 x stabilisers like the Sanctum www.sanctumsurf.com.au/stablizer-fcs up front.

But then placement in relation to each other apparently comes into play due to slip streaming effects? Not entirely sure on that one as trailing fin does not follow the same flow lines as the leading one? But it seems that there is some form of hydrodynamic interaction between them, and for my two bobs worth as a fluid mechanics engineer I would hazard that it has more to do with fluid release in the cavity between the fins. Unlike a big triple tab keel fin which would present similar surface area to the 2 + 2 twinzer, the twinzer would allow pressure relief through the cavity between the fins. In simple terms it's called the path of least resistance, all energy conforms to this truth, pressure, flow, heat, sound etc. all want to find a steady state and return to it as efficiently as possible against the resistance that presents itself.

In this case the fins, confined within the form of the board shape and design. A very dynamic field of variables that even does my head in and I work with this stuff daily.

Still after a while you become intuitive, just like shapers with the designs that hey make. Intuitively over time, trail and error they become aware of what does and does not work. And between them and different designs you see a lot of synergy as their design features coalesce.

But fins, well up until recently they have remained reasonably unchanged in shape and features, and only now are conventional concepts and the mainstay of the thruster being challenged by new shapes as well as geometric and composite material design features, placements, combinations etc.

Resulting in people discovering just how much effect a set of fins and their design features can have on a boards performance.




Shortboard customs arent dear if you go to the right places.
You arent pay for a retail shop. overheads extra extra.
This board will work well just swapping around the quads.
Having said that this shaper does have a dedicated twinzer model.
Its a wild looking setup. Not brave enough yet

Twinzer



The custom model im getting

Hydromann
626 posts
6 Feb 2020 11:32AM
Thumbs Up

Select to expand quote
laceys lane said..

Hydromann said..




laceys lane said..






Hydromann said..
Has anyone considered Twinzer setups?








Im thinking about it on a shortboard ive ordered.Just a swap around of quads.
My shaper considers it good on the board im getting.

Im one those ancient guys that orders their boards from the shaper. Not the shop front sales guy.
Cant get my head around guys getting big money customs and they never speak to the shaper.

If you go custom at least speak to the guy shaping it







I didn't go custom, couldn't afford it or justify the added cost for my level of surfing. Coming back into it after 20 years I just needed something to suit the wish list I had that would allow some experimentation.

So I bought a 6'10" mid length with multi fin placement plugs.

The swap around of quads seems a little more complex depending on which shaper you listen to and their experience and technical knowledge.

Most state that you need to use dedicated design twin fins at the rear, not just the larger quads. And then use 2 x stabilisers like the Sanctum www.sanctumsurf.com.au/stablizer-fcs up front.

But then placement in relation to each other apparently comes into play due to slip streaming effects? Not entirely sure on that one as trailing fin does not follow the same flow lines as the leading one? But it seems that there is some form of hydrodynamic interaction between them, and for my two bobs worth as a fluid mechanics engineer I would hazard that it has more to do with fluid release in the cavity between the fins. Unlike a big triple tab keel fin which would present similar surface area to the 2 + 2 twinzer, the twinzer would allow pressure relief through the cavity between the fins. In simple terms it's called the path of least resistance, all energy conforms to this truth, pressure, flow, heat, sound etc. all want to find a steady state and return to it as efficiently as possible against the resistance that presents itself.

In this case the fins, confined within the form of the board shape and design. A very dynamic field of variables that even does my head in and I work with this stuff daily.

Still after a while you become intuitive, just like shapers with the designs that hey make. Intuitively over time, trail and error they become aware of what does and does not work. And between them and different designs you see a lot of synergy as their design features coalesce.

But fins, well up until recently they have remained reasonably unchanged in shape and features, and only now are conventional concepts and the mainstay of the thruster being challenged by new shapes as well as geometric and composite material design features, placements, combinations etc.

Resulting in people discovering just how much effect a set of fins and their design features can have on a boards performance.





Shortboard customs arent dear if you go to the right places.
You arent pay for a retail shop. overheads extra extra.
This board will work well just swapping around the quads.
Having said that this shaper does have a dedicated twinzer model.
Its a wild looking setup. Not brave enough yet

Twinzer



The custom model im getting


Holy crap look at the concave in the nose of that thing. Almost looks like a knee board.

Fin placement is so subjective even between shapers who have different takes and understandings.

Your bloke looks like his dedicated Twinzer subscribes to the hydrodynamic overlap and effects.

But the throws that out the window on your custom. Looking more like a 2+2 arrangement.

I'm looking this guy up, I like his brain.

Hope your ride turns out awesome for you. Bottom line is as long as it floats you can catch a wave. What you do with it after that and how you drive it then becomes a relationship ??

laceys lane
QLD, 19803 posts
6 Feb 2020 1:54PM
Thumbs Up

Look. Ill give the swap around quad arrangement ago

Hydromann
626 posts
6 Feb 2020 12:13PM
Thumbs Up

Select to expand quote
laceys lane said..
Look. Ill give the swap around quad arrangement ago


Same..

MickPC
8266 posts
6 Feb 2020 4:11PM
Thumbs Up

Select to expand quote
laceys lane said..
Look. Ill give the swap around quad arrangement ago


Looks very Interesting, let us know how it goes

MickPC
8266 posts
6 Feb 2020 4:17PM
Thumbs Up

Select to expand quote
Cuttlefish said..

Hydromann said..


Cuttlefish said..
These would be better for your carbon jet. Run them as a twin or twin with either a centre trailer or with small trailers in the quad plugs.
They will have less flex than the Modii's and a more area in the tips.
www.gumtree.com.au/s-ad/burleigh-heads/surfing/surfboard-fins-akila-aipa-twin-fins-fcs/1235082334
Trailers for sale here:
www.sanctumsurf.com.au/stablizer-fcs





These look interesting....

Not twins as such but maybe a nice option for rears in a quad?

www.gumtree.com.au/s-ad/grafton/surfing/fcs-fins-with-venturi-channels-and-winglets/1228665911

Reminds me of Roy Stuart's fin designs www.roystuart.biz/ mixed with some Fin Sciences design concepts finsciences.com/surfboard-fin-science/

Fin sciences is interesting, he uses a lot of "tech" talk to try and explain why "modern" wing design is better than bio-mimicry, but what he fails to recognise or tell people is that modern solutions where developed to deal with modern supersonic problems. From a sub sonic perspective the difference in velocity and the loss based on tip turbulence is negligible. 90% of surfboard fins etc are simply not going fast enough for tip velocity to make such a significant difference to 85% of surfers who will never notice.

The bigger performance compromise would be to do with stall, the angle at which a wing looses it lift capacity. For a fin this would be the angle at which the fin breaks hold of the water and shears.

That's where Roy's messing about with tubercles on leading edges is interesting, whilst he has a very limited scientific understanding he has an amazing intuitive comprehension, that is the ability of the brain to envisage dynamic concepts and interactions.

The tubercles break the laminar flow into a mix of smaller pockets of turbulent and laminar flow streams. This naturally causes a slight drag loss but overcomes the stall issues of the wing. Without them a humpback would not be able to make the tight turns it needs to in order to round up and catch it's food. It would stall through a turn and shear until it corrected the attack angle.

The venturi channel fins whilst not exactly tubercles would essentially have a similar effect, but they would also have the effect of creating higher lift for the foil shape due to greater drag over the longer surface.

And then there's the latest fins from Cheyne Horan which have some merrit as well www.cheynehoran.com.au/fins/

If you took the shape of Cheyne's fins and designed in the venturi channels and winglet then I think that would be an optimised fin design.

For my two cents worth I think the future of surfing will be found in fin design and placement, FCS, Futures and others have done some great work on fitment systems, composite materials for flex control etc. But I think you will see them experiment more with some of the concepts that Roy has pioneered.

And shapers will have a whole new field of designs to consider the dynamic effect of in the whole of the surfboard design.



My brain hurts.
Oh and careful speaking he "who should not be named" name out loud lest he re-visit all the different forums with spam posts.


lol personally I wish for his return

Cuttlefish
QLD, 1332 posts
6 Feb 2020 6:27PM
Thumbs Up

Select to expand quote
laceys lane said..

Hydromann said..




laceys lane said..






Hydromann said..
Has anyone considered Twinzer setups?








Im thinking about it on a shortboard ive ordered.Just a swap around of quads.
My shaper considers it good on the board im getting.

Im one those ancient guys that orders their boards from the shaper. Not the shop front sales guy.
Cant get my head around guys getting big money customs and they never speak to the shaper.

If you go custom at least speak to the guy shaping it







I didn't go custom, couldn't afford it or justify the added cost for my level of surfing. Coming back into it after 20 years I just needed something to suit the wish list I had that would allow some experimentation.

So I bought a 6'10" mid length with multi fin placement plugs.

The swap around of quads seems a little more complex depending on which shaper you listen to and their experience and technical knowledge.

Most state that you need to use dedicated design twin fins at the rear, not just the larger quads. And then use 2 x stabilisers like the Sanctum www.sanctumsurf.com.au/stablizer-fcs up front.

But then placement in relation to each other apparently comes into play due to slip streaming effects? Not entirely sure on that one as trailing fin does not follow the same flow lines as the leading one? But it seems that there is some form of hydrodynamic interaction between them, and for my two bobs worth as a fluid mechanics engineer I would hazard that it has more to do with fluid release in the cavity between the fins. Unlike a big triple tab keel fin which would present similar surface area to the 2 + 2 twinzer, the twinzer would allow pressure relief through the cavity between the fins. In simple terms it's called the path of least resistance, all energy conforms to this truth, pressure, flow, heat, sound etc. all want to find a steady state and return to it as efficiently as possible against the resistance that presents itself.

In this case the fins, confined within the form of the board shape and design. A very dynamic field of variables that even does my head in and I work with this stuff daily.

Still after a while you become intuitive, just like shapers with the designs that hey make. Intuitively over time, trail and error they become aware of what does and does not work. And between them and different designs you see a lot of synergy as their design features coalesce.

But fins, well up until recently they have remained reasonably unchanged in shape and features, and only now are conventional concepts and the mainstay of the thruster being challenged by new shapes as well as geometric and composite material design features, placements, combinations etc.

Resulting in people discovering just how much effect a set of fins and their design features can have on a boards performance.





Shortboard customs arent dear if you go to the right places.
You arent pay for a retail shop. overheads extra extra.
This board will work well just swapping around the quads.
Having said that this shaper does have a dedicated twinzer model.
Its a wild looking setup. Not brave enough yet

Twinzer



The custom model im getting


Muzza is such a good shaper. Still not afraid to continue experimenting with out there concepts after all these years instead of pumping out the conservative bread and butter shapes ad infintum.
My first "normal" surfboard was a 6 channel, pintail, single fine Pipedreams all of 5'10" long. I say normal as I learnt on a Crozier single fin slab kneeboard.

laceys lane
QLD, 19803 posts
6 Feb 2020 6:35PM
Thumbs Up

That freiken flyer is quite as radical as the photos suggests.
Should have it soon..he's been turning them our in 2 weeks ish lately

Macaha
QLD, 21900 posts
6 Feb 2020 11:31PM
Thumbs Up

Select to expand quote
laceys lane said..
That freiken flyer is quite as radical as the photos suggests.
Should have it soon..he's been turning them our in 2 weeks ish lately


Sounds awesome but are they 9 plus boards? If not why is this rubbish being posted here?

Hydromann
626 posts
6 Feb 2020 10:03PM
Thumbs Up

Select to expand quote
Macaha said..


laceys lane said..
That freiken flyer is quite as radical as the photos suggests.
Should have it soon..he's been turning them our in 2 weeks ish lately




Sounds awesome but are they 9 plus boards? If not why is this rubbish being posted here?



Title says it, twins on a mid length.

Feel fee to join in with how you reckon twins on a Longboard would go as well.

Don't think I've ever seen one in the flesh running twinnies.

laceys lane
QLD, 19803 posts
7 Feb 2020 2:27AM
Thumbs Up

Select to expand quote
Macaha said..




laceys lane said..
That freiken flyer is quite as radical as the photos suggests.
Should have it soon..he's been turning them our in 2 weeks ish lately






Sounds awesome but are they 9 plus boards? If not why is this rubbish being posted here?





Here we go.
Mac trying to rule the roost
It was only a matter of time. I knew it from his earlier post
He has you in his sights hydro. Just hasnt quite go the guts yet so hes going me- piss off mac
Stop being a jealous dick

Ps. Good evening Hope your relaxing over there mac

Hydromann
626 posts
7 Feb 2020 2:20AM
Thumbs Up

Select to expand quote
laceys lane said..

Macaha said..




laceys lane said..
That freiken flyer is quite as radical as the photos suggests.
Should have it soon..he's been turning them our in 2 weeks ish lately






Sounds awesome but are they 9 plus boards? If not why is this rubbish being posted here?





Here we go.
Mac trying to rule the roost
It was only a matter of time. I inew it from his earlier post
He has you in his sights hydro. Just hasnt quite go the guts yet so hes going me- piss off mac
Stop being a jealous dick

Ps. Good evening Hope your relaxing over there mac


Me in his sights?

Whatever did I do?

I just politely pointed out what the grown ups were talking about when he took it upon himself to interrupt and have a little dummy spit.

I then nicely invited him to join in the discussion with something relevant to his expertise.

I got no quarrels with MAC or anyone else here. I simply state my opinions based on a bit more thought than resentments, prejudice and bias.

If Mac or anyone want to challenge my perspectives with facts I welcome it, I honestly value anyone and everyone's views and opinions that challenge mine.

Because at the end of the day if I am arrogantly wrong and accept no feedback then that shows a complete lack of character and consideration on my part.

So if Mac or anyone strongly disagrees with anything I post, and can prove I am wrong or mistaken based on fact the I will happily retract my statements and learn from them.

So now that is clear can we get back to discussion on twins, twinzers, duos or any other configuration of two fins attached to any size or shape surfing device including mid length, long board, short board, boogie board, knee board, skim board, water ski, rescue board, hand plane or even surf matt.

It's all fun and educational.

That is all.

Hydromann
626 posts
7 Feb 2020 2:20AM
Thumbs Up

Select to expand quote
laceys lane said..

Macaha said..




laceys lane said..
That freiken flyer is quite as radical as the photos suggests.
Should have it soon..he's been turning them our in 2 weeks ish lately






Sounds awesome but are they 9 plus boards? If not why is this rubbish being posted here?





Here we go.
Mac trying to rule the roost
It was only a matter of time. I inew it from his earlier post
He has you in his sights hydro. Just hasnt quite go the guts yet so hes going me- piss off mac
Stop being a jealous dick

Ps. Good evening Hope your relaxing over there mac


Me in his sights?

Whatever did I do?

I just politely pointed out what the grown ups were talking about when he took it upon himself to interrupt and have a little dummy spit.

I then nicely invited him to join in the discussion with something relevant to his expertise.

I got no quarrels with MAC or anyone else here. I simply state my opinions based on a bit more thought than resentments, prejudice and bias.

If Mac or anyone want to challenge my perspectives with facts I welcome it, I honestly value anyone and everyone's views and opinions that challenge mine.

Because at the end of the day if I am arrogantly wrong and accept no feedback then that shows a complete lack of character and consideration on my part.

So if Mac or anyone strongly disagrees with anything I post, and can prove I am wrong or mistaken based on fact the I will happily retract my statements and learn from them.

So now that is clear can we get back to discussion on twins, twinzers, duos or any other configuration of two fins attached to any size or shape surfing device including mid length, long board, short board, boogie board, knee board, skim board, water ski, rescue board, hand plane or even surf matt.

It's all fun and educational.

That is all.

Cuttlefish
QLD, 1332 posts
7 Feb 2020 4:29AM
Thumbs Up

Waiting for the sun to come up so I can go surfing.
www.seabreeze.com.au/forums/Surfing/Longboarding/Can-you-tell-me-about-my-board?page=1

laceys lane
QLD, 19803 posts
7 Feb 2020 6:35AM
Thumbs Up

Select to expand quote
Hydromann said..

laceys lane said..


Macaha said..





laceys lane said..
That freiken flyer is quite as radical as the photos suggests.
Should have it soon..he's been turning them our in 2 weeks ish lately







Sounds awesome but are they 9 plus boards? If not why is this rubbish being posted here?






Here we go.
Mac trying to rule the roost
It was only a matter of time. I inew it from his earlier post
He has you in his sights hydro. Just hasnt quite go the guts yet so hes going me- piss off mac
Stop being a jealous dick

Ps. Good evening Hope your relaxing over there mac



Me in his sights?

Whatever did I do?

I just politely pointed out what the grown ups were talking about when he took it upon himself to interrupt and have a little dummy spit.

I then nicely invited him to join in the discussion with something relevant to his expertise.

I got no quarrels with MAC or anyone else here. I simply state my opinions based on a bit more thought than resentments, prejudice and bias.

If Mac or anyone want to challenge my perspectives with facts I welcome it, I honestly value anyone and everyone's views and opinions that challenge mine.

Because at the end of the day if I am arrogantly wrong and accept no feedback then that shows a complete lack of character and consideration on my part.

So if Mac or anyone strongly disagrees with anything I post, and can prove I am wrong or mistaken based on fact the I will happily retract my statements and learn from them.

So now that is clear can we get back to discussion on twins, twinzers, duos or any other configuration of two fins attached to any size or shape surfing device including mid length, long board, short board, boogie board, knee board, skim board, water ski, rescue board, hand plane or even surf matt.

It's all fun and educational.

That is all.


He just has this Hitler problem

Macaha
QLD, 21900 posts
7 Feb 2020 8:46AM
Thumbs Up

Thread of the year, have a lovely day gentlemen.

Macaha
QLD, 21900 posts
7 Feb 2020 9:23AM
Thumbs Up

Select to expand quote
Hydromann said..

laceys lane said..


Macaha said..





laceys lane said..
That freiken flyer is quite as radical as the photos suggests.
Should have it soon..he's been turning them our in 2 weeks ish lately







Sounds awesome but are they 9 plus boards? If not why is this rubbish being posted here?






Here we go.
Mac trying to rule the roost
It was only a matter of time. I inew it from his earlier post
He has you in his sights hydro. Just hasnt quite go the guts yet so hes going me- piss off mac
Stop being a jealous dick

Ps. Good evening Hope your relaxing over there mac



Me in his sights?

Whatever did I do?

I just politely pointed out what the grown ups were talking about when he took it upon himself to interrupt and have a little dummy spit.

I then nicely invited him to join in the discussion with something relevant to his expertise.

I got no quarrels with MAC or anyone else here. I simply state my opinions based on a bit more thought than resentments, prejudice and bias.

If Mac or anyone want to challenge my perspectives with facts I welcome it, I honestly value anyone and everyone's views and opinions that challenge mine.

Because at the end of the day if I am arrogantly wrong and accept no feedback then that shows a complete lack of character and consideration on my part.

So if Mac or anyone strongly disagrees with anything I post, and can prove I am wrong or mistaken based on fact the I will happily retract my statements and learn from them.

So now that is clear can we get back to discussion on twins, twinzers, duos or any other configuration of two fins attached to any size or shape surfing device including mid length, long board, short board, boogie board, knee board, skim board, water ski, rescue board, hand plane or even surf matt.

It's all fun and educational.

That is all.


I'm not smart enough to disagree with anyone

laceys lane
QLD, 19803 posts
7 Feb 2020 9:52AM
Thumbs Up

Ahhh. Its another day



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Forums > Surfing Longboarding


"Twin on midlength." started by WindNoob