Fin setup for a quad
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Bramo
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Fin setup for a quad
Ordering a new board soon and need some help with the fin placement. Looking at a squash tail, quad setup with an extra plug to change it to a thruster. How far should the fins be from the tail? Any help will be appreciated. Thanks.
Howzit Bramo,
Best is probably to troll thru the "kneelo design" forum & also spy out the board photo album, theres tons of info there, but I dunno if youre gonna be lucky enough to get an answer to the nearest inch ( or cm).
Ive also got a half shaped thruster Im thinking of adding fin plugs to so I can play quad.....
cheers
Andy
Best is probably to troll thru the "kneelo design" forum & also spy out the board photo album, theres tons of info there, but I dunno if youre gonna be lucky enough to get an answer to the nearest inch ( or cm).
Ive also got a half shaped thruster Im thinking of adding fin plugs to so I can play quad.....
cheers
Andy
-
bdwqld
- Ripper (more than 100 posts)
- Posts: 236
- Joined: Tue Dec 12, 2006 7:05 pm
- Location: Queensland Australia
- Contact:
I found this article whilst trolling the web in search of the same knowledge. This is by a guy called Mckee who has been shaping both stand up and kneelos as quad arrangements for many years. It made sense after reading it about 5 times. 
It does tend to talk along the stand up line but you get the gist of how it will work for a kneelo.
I lifted it from "MCKEE’s look in detail at the NITTY GRITTY of quad fin technicalities."
Quote:
" MCKEE’s look in detail at the NITTY GRITTY of quad fin technicalities.
How quads work & How quads differ from thrusters
• Quads give more drive, speed, security, climb the foam better, let you drop in and drive without nursing the bottom turn. They can drive everywhere with a greater boost than a thruster so sometimes you must adjust your technique to cater for this new boost of energy. By knowing how to fine tune them they can be adjusted to perform in practically any way you desire.
• Quads are faster due to having all fins driving through turns, or even just running across a wave face. All fins are propelling the board forward much like sails or propeller blades. This is because a board in these situations, is in a constant lateral drift and the water passing under the board, divides between the fins to pass out both sides of the tail while redirecting off the fins, rearward, to form thrust.
• The back fin of a thruster generally sits in the dividing line of this displaced water so provides no added speed but gives direction and control with a dragging effect.
• Depending on your fin positioning or ‘cluster’, your quad can be as pivotal as you want. The goal is, though, to select a fin positioning formula that provides a balance of looseness, drive and security, a happy medium you might say. Like cars, you can have a long wheel-base or a short wheel-base, or something in the middle. It’s the same with fin positioning on surfboards. The McKee Multisystem formula is a good choice for that ‘happy medium’.
• Comparing quad fins to car wheels is a simplified way of imagining the corresponding affects of changing fins. Big stiff fins= Big grippy tyres. Flexy fins= Soft low air tyres. Thus big stiff wheels on the front plus Soft or small low air tyres on the back gives a car with a lot of oversteer. Bigger rear tyres than front = like a formula one race car.
• Pivot can also be adjusted depending on your fin selection. Rear double-foiled fins, compared to flat-faced fins of the same size, will pivot more. Larger proportioned front fins than rear fins will also pivot more. Fins that have less rake are more pivotal.
• The fins should be balanced around what is called the ‘sweet spot’. The sweet spot is generally the position of the back foot when performing a cutback or top turn. Boards will ‘over-steer’,’ under-steer’, or feel neutral depending on all these factors of rake, size and foil and how they relate to the location of the ‘sweet spot’.
• The sweet spot is determined by the tail area, plan-shape and length of the board.
• If one side of the board has different fins to the other side, it will be like two different boards when turning right or left. Asymmetric mixes are another way to ultra fine tuning a board for point break conditions.
• Control
• Control comes from the correct choice of fins for the surf conditions.
• Depending on the type of board and size of the wave, a different turning arc and amount of hold are needed.
• Quads with the correct fin choice have much more hold than ‘Thrusters’. The worry of the Thruster’s central tail fin leaving the water is eliminated with a quad. No more ’nursing’ the turn.
• Drag
• Too much toe-in of the fins can create a quick accelerating, loose but ultimately draggy board as the fins start to wedge-up at high speeds. Increased Vee will reduce the effect as it ‘feeds’ the fins.
• Low speeds
• More ‘toe in’ as with three-fins and twin -fins loosens up boards for small waves and low speeds. This is generally determined as the shaper’s choice.
Choosing a quad
• Different shapes for different waves:
• My shapes for quads are exactly the same as I would shape for three fins, though obviously for those wide tailed fish or with any wide tailed board, if you want them to hang-in in bigger waves, then a quad setup is the best choice.
• VEE tails do ‘feed’ a quad’s two back fins by dividing the water between the fins thus reducing the possibility of a wedging effect, though with the correct ‘toe-in’ angle this should not be a problem when a concave tail is required.
Quad fin selection
• The mentality that quads are for small waves and three fins are for power waves is still promoted by some die-hards. I would suggest that they actually try a quad in power waves and thus this incorrect fallacy would be instantly extinguished.
• The addition of an extra fin on the tail will obviously add to the total fin surface area thus providing more hold.
• The addition of the fourth fin leads many to reduce the size of the back fins in relation to what would have been used if the board were a thruster. A heavy back-footed surfer will relish in the extra hold of an extra back fin of equal size to that out of their thruster set. This requires a new full-powered approach to surfing and the only limit will be your own leg strength and talent.
• ‘Front-foot’ surfers or those needing a less demanding effort to turn will benefit from reduced size back fins of double foil and or all fins of reduced size.
Fin placement & rear fin choice?
• In the past l have placed fins in hundreds of different positions all over the tail. For the ‘M4Quattro’ purist, the ‘Mckee M5 Multisystem’ is just a security blanket or like training wheels because for them the ‘Thruster’s’ central fin is obsolete. The quad cluster can be moved forward to loosen up a board and for shapers of custom boards, many compensations can be made for weaker riders or for special needs such as looser guns but with the advantage of not losing drive. Although taken off the current formula there is the shapers option to move the cluster at any amount not exceeding the stupidity level. I personally had great results on pintails by moving the positions forward up to 2cm or ¾” forward. The videos of Tom Carroll in Hawaii are examples of the result of these positions --- The variations are limitless!
With the rear fin positions, the closer they get to the rails the more hold, yet the greater the time delay in re-centering the board in preparation for the next turn. You also produce a greater ‘twin-fin’ effect, with the board feeling like it is staying on one tack, needing you to throw it across between turns. Also you increase the risk of ‘rail-grabbing’. There is a correct distance between the back fins correlated to the tail width at 12” up. Fins close to the rail mean that they have to be reduced in size or toed-in more than fins placed closer to the stringer. There is a happy medium that provides a ‘thruster-like’ re-centering with the correct amount of drive. This also allows for the use of larger rear fins, still providing looseness but without having any rail grab to worry about.
• Choice of rear fin should be determined by your weight, power, wave size and type of board, say shortboard or gun.
• Guns and boards for waves with push, generally need more control than drive and a more forgiving lateral movement when riding forward on the board, so double foiled back fins are my choice here.
• Fish and guns over 6’8” generally gave a greater difference in size between the front and rear fins. Shortboards under 6’8” for power waves can have fins of a closer size depending on the looseness required.
• The further forward they are on the board
The looser and more pivotal a board will become. Overdoing it, and you enter into a situation of over-steer. You are moving the fin positions forward of the ‘sweet-spot’ so the board can become unbalanced.
On guns and long-boards, this is can be an added benefit. If you forget about the ‘Multisystem’ concept (the option of a central ‘Thruster’ tail fin), the cluster can be moved forward to leave those guns and longboards as loose as you like without the worry, as in three fins, of the tail fins leaving the water. I recommend a maximum of an extra 2cm further forward on the McKee formula so as to not get too crazy. On shortboards big movements forward are not so advisable as there is not as much nose length and weight to counterbalance the oversteer…Though if you like 360s..
• If you use the McKee Quattro & Multisystem formula the size ratio between the front and back fins can become a lot closer, even to the point where a strong surfer in power waves may choose to have bigger back fins than front for full directional drive.
• Distance from the tail and the location of the cluster in relation to the sweet spot will be a determining factor on choice of front and rear fin size correct for your weight and ability.
Tuning your quad fin setup to work best for you.
Is the tail sliding too easily? Go with a larger rear fin set
Is the tail too tight? Go with a slightly smaller rear fin set
Is the board lacking drive? Go with slightly larger front fins.
Is the board too hard to turn? Go with slightly smaller front fins and rear fins.
Does the board feel out of control? Try a rear fin with a symmetrical or 80/20 foil
Wanting drive off the bottom and loose of the top? Place a flatter foil or bigger rear fin for the bottom turn side and a smaller double foiled rear fin on the off the top side.. note that this will also be the cutback side so study your choices.
Well have fun and I look forward to some feedback!
McKee. "
End Quote
Happy Reading
It does tend to talk along the stand up line but you get the gist of how it will work for a kneelo.
I lifted it from "MCKEE’s look in detail at the NITTY GRITTY of quad fin technicalities."
Quote:
" MCKEE’s look in detail at the NITTY GRITTY of quad fin technicalities.
How quads work & How quads differ from thrusters
• Quads give more drive, speed, security, climb the foam better, let you drop in and drive without nursing the bottom turn. They can drive everywhere with a greater boost than a thruster so sometimes you must adjust your technique to cater for this new boost of energy. By knowing how to fine tune them they can be adjusted to perform in practically any way you desire.
• Quads are faster due to having all fins driving through turns, or even just running across a wave face. All fins are propelling the board forward much like sails or propeller blades. This is because a board in these situations, is in a constant lateral drift and the water passing under the board, divides between the fins to pass out both sides of the tail while redirecting off the fins, rearward, to form thrust.
• The back fin of a thruster generally sits in the dividing line of this displaced water so provides no added speed but gives direction and control with a dragging effect.
• Depending on your fin positioning or ‘cluster’, your quad can be as pivotal as you want. The goal is, though, to select a fin positioning formula that provides a balance of looseness, drive and security, a happy medium you might say. Like cars, you can have a long wheel-base or a short wheel-base, or something in the middle. It’s the same with fin positioning on surfboards. The McKee Multisystem formula is a good choice for that ‘happy medium’.
• Comparing quad fins to car wheels is a simplified way of imagining the corresponding affects of changing fins. Big stiff fins= Big grippy tyres. Flexy fins= Soft low air tyres. Thus big stiff wheels on the front plus Soft or small low air tyres on the back gives a car with a lot of oversteer. Bigger rear tyres than front = like a formula one race car.
• Pivot can also be adjusted depending on your fin selection. Rear double-foiled fins, compared to flat-faced fins of the same size, will pivot more. Larger proportioned front fins than rear fins will also pivot more. Fins that have less rake are more pivotal.
• The fins should be balanced around what is called the ‘sweet spot’. The sweet spot is generally the position of the back foot when performing a cutback or top turn. Boards will ‘over-steer’,’ under-steer’, or feel neutral depending on all these factors of rake, size and foil and how they relate to the location of the ‘sweet spot’.
• The sweet spot is determined by the tail area, plan-shape and length of the board.
• If one side of the board has different fins to the other side, it will be like two different boards when turning right or left. Asymmetric mixes are another way to ultra fine tuning a board for point break conditions.
• Control
• Control comes from the correct choice of fins for the surf conditions.
• Depending on the type of board and size of the wave, a different turning arc and amount of hold are needed.
• Quads with the correct fin choice have much more hold than ‘Thrusters’. The worry of the Thruster’s central tail fin leaving the water is eliminated with a quad. No more ’nursing’ the turn.
• Drag
• Too much toe-in of the fins can create a quick accelerating, loose but ultimately draggy board as the fins start to wedge-up at high speeds. Increased Vee will reduce the effect as it ‘feeds’ the fins.
• Low speeds
• More ‘toe in’ as with three-fins and twin -fins loosens up boards for small waves and low speeds. This is generally determined as the shaper’s choice.
Choosing a quad
• Different shapes for different waves:
• My shapes for quads are exactly the same as I would shape for three fins, though obviously for those wide tailed fish or with any wide tailed board, if you want them to hang-in in bigger waves, then a quad setup is the best choice.
• VEE tails do ‘feed’ a quad’s two back fins by dividing the water between the fins thus reducing the possibility of a wedging effect, though with the correct ‘toe-in’ angle this should not be a problem when a concave tail is required.
Quad fin selection
• The mentality that quads are for small waves and three fins are for power waves is still promoted by some die-hards. I would suggest that they actually try a quad in power waves and thus this incorrect fallacy would be instantly extinguished.
• The addition of an extra fin on the tail will obviously add to the total fin surface area thus providing more hold.
• The addition of the fourth fin leads many to reduce the size of the back fins in relation to what would have been used if the board were a thruster. A heavy back-footed surfer will relish in the extra hold of an extra back fin of equal size to that out of their thruster set. This requires a new full-powered approach to surfing and the only limit will be your own leg strength and talent.
• ‘Front-foot’ surfers or those needing a less demanding effort to turn will benefit from reduced size back fins of double foil and or all fins of reduced size.
Fin placement & rear fin choice?
• In the past l have placed fins in hundreds of different positions all over the tail. For the ‘M4Quattro’ purist, the ‘Mckee M5 Multisystem’ is just a security blanket or like training wheels because for them the ‘Thruster’s’ central fin is obsolete. The quad cluster can be moved forward to loosen up a board and for shapers of custom boards, many compensations can be made for weaker riders or for special needs such as looser guns but with the advantage of not losing drive. Although taken off the current formula there is the shapers option to move the cluster at any amount not exceeding the stupidity level. I personally had great results on pintails by moving the positions forward up to 2cm or ¾” forward. The videos of Tom Carroll in Hawaii are examples of the result of these positions --- The variations are limitless!
With the rear fin positions, the closer they get to the rails the more hold, yet the greater the time delay in re-centering the board in preparation for the next turn. You also produce a greater ‘twin-fin’ effect, with the board feeling like it is staying on one tack, needing you to throw it across between turns. Also you increase the risk of ‘rail-grabbing’. There is a correct distance between the back fins correlated to the tail width at 12” up. Fins close to the rail mean that they have to be reduced in size or toed-in more than fins placed closer to the stringer. There is a happy medium that provides a ‘thruster-like’ re-centering with the correct amount of drive. This also allows for the use of larger rear fins, still providing looseness but without having any rail grab to worry about.
• Choice of rear fin should be determined by your weight, power, wave size and type of board, say shortboard or gun.
• Guns and boards for waves with push, generally need more control than drive and a more forgiving lateral movement when riding forward on the board, so double foiled back fins are my choice here.
• Fish and guns over 6’8” generally gave a greater difference in size between the front and rear fins. Shortboards under 6’8” for power waves can have fins of a closer size depending on the looseness required.
• The further forward they are on the board
The looser and more pivotal a board will become. Overdoing it, and you enter into a situation of over-steer. You are moving the fin positions forward of the ‘sweet-spot’ so the board can become unbalanced.
On guns and long-boards, this is can be an added benefit. If you forget about the ‘Multisystem’ concept (the option of a central ‘Thruster’ tail fin), the cluster can be moved forward to leave those guns and longboards as loose as you like without the worry, as in three fins, of the tail fins leaving the water. I recommend a maximum of an extra 2cm further forward on the McKee formula so as to not get too crazy. On shortboards big movements forward are not so advisable as there is not as much nose length and weight to counterbalance the oversteer…Though if you like 360s..
• If you use the McKee Quattro & Multisystem formula the size ratio between the front and back fins can become a lot closer, even to the point where a strong surfer in power waves may choose to have bigger back fins than front for full directional drive.
• Distance from the tail and the location of the cluster in relation to the sweet spot will be a determining factor on choice of front and rear fin size correct for your weight and ability.
Tuning your quad fin setup to work best for you.
Is the tail sliding too easily? Go with a larger rear fin set
Is the tail too tight? Go with a slightly smaller rear fin set
Is the board lacking drive? Go with slightly larger front fins.
Is the board too hard to turn? Go with slightly smaller front fins and rear fins.
Does the board feel out of control? Try a rear fin with a symmetrical or 80/20 foil
Wanting drive off the bottom and loose of the top? Place a flatter foil or bigger rear fin for the bottom turn side and a smaller double foiled rear fin on the off the top side.. note that this will also be the cutback side so study your choices.
Well have fun and I look forward to some feedback!
McKee. "
End Quote
Happy Reading
"Start at the Knees Please"
http://neepro.blogspot.com/
http://neepro.blogspot.com/
that looks like pretty good information.
I had a thruster with a proven template and proven bottom in the sense it was a design I'd refined through different shapers over a ten-15 year period. I rode the board & it was a pig, and it sat in the rafters brand new for about four years. After breaking my last good board, I took it down, and instead of shooting arrows into it, I knocked the three fins off & turned it into a quad. To this day, it was one of the very best boards I've ever had. I haven't used a thruster since.
I've always liked glassed fins because they're easy to knock of & move around if something isn't quite right. They just don't travel well. Experiment with works for your style of surfing before you worry about boxes or plug placement. After you know what works for you, boxes are good... especially for travel. I have both my front & rear fins handmade to my templates.
Fins, & where you put 'em, make or break a board. Don't be afraid to experiment. Either that, or you can bring it over to my house and we can both shoot arrows into it.
I had a thruster with a proven template and proven bottom in the sense it was a design I'd refined through different shapers over a ten-15 year period. I rode the board & it was a pig, and it sat in the rafters brand new for about four years. After breaking my last good board, I took it down, and instead of shooting arrows into it, I knocked the three fins off & turned it into a quad. To this day, it was one of the very best boards I've ever had. I haven't used a thruster since.
I've always liked glassed fins because they're easy to knock of & move around if something isn't quite right. They just don't travel well. Experiment with works for your style of surfing before you worry about boxes or plug placement. After you know what works for you, boxes are good... especially for travel. I have both my front & rear fins handmade to my templates.
Fins, & where you put 'em, make or break a board. Don't be afraid to experiment. Either that, or you can bring it over to my house and we can both shoot arrows into it.
Bramo, if you don't mind having an extra set of plugs (three sets) you could set it up so that with the fins in the front two sets you have a fins forward quad and with the fins in the back two sets you have a fins back quad. Throw in an adjustable system like Lokbox and you can fine tune it even more.
Captain Kneemo fan club
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kneeanderthal
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kneeanderthal
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bdwqld
- Ripper (more than 100 posts)
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- Joined: Tue Dec 12, 2006 7:05 pm
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As KenM suggested you could try something like this.
[fullalbumimg]28634[/fullalbumimg]
I have had a lot of fun shifting fins around to different positions. The board on the left is my latest. I asked Dean Cleary to change from the FCS plugs to the FCS Fusion boxes which lead to a different arrangement that makes sense when you have read the Mckee article.
[fullalbumimg]28634[/fullalbumimg]
I have had a lot of fun shifting fins around to different positions. The board on the left is my latest. I asked Dean Cleary to change from the FCS plugs to the FCS Fusion boxes which lead to a different arrangement that makes sense when you have read the Mckee article.
"Start at the Knees Please"
http://neepro.blogspot.com/
http://neepro.blogspot.com/
-
bdwqld
- Ripper (more than 100 posts)
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- Joined: Tue Dec 12, 2006 7:05 pm
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More Fin Fun 
This is for standup and would have to be adjusted for our beloved kneeboards.
http://www.mckeesurf.com/brucemckee/multisystem.htm
http://www.mckeesurf.com/brucemckee/fingraphic.htm
This is for standup and would have to be adjusted for our beloved kneeboards.
http://www.mckeesurf.com/brucemckee/multisystem.htm
http://www.mckeesurf.com/brucemckee/fingraphic.htm
"Start at the Knees Please"
http://neepro.blogspot.com/
http://neepro.blogspot.com/
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Bramo
- Grom (25 or less posts to site)
- Posts: 21
- Joined: Mon May 03, 2010 10:57 pm
- Location: Pringle Bay, South Africa
Thanks guys, this helps a lot! I started surfing a thruster until a friend said I must try his quad and since then no turning back. My new board was going to be exactly the same but then someone said try something different so that's why I thought maybe a combination of thruster and quad.
KenM, think that is a great idea. So many options.
Tim, Ian Kitching form George shaped my last board and did a real good job so he is definitely shaping my new one. Try to load some pics of it but i won't work.
bdwqld, think your article changed my mind to just sticking to a quad (I sure love surfing them). Thinking of going your way, Ken!
Thanks again
KenM, think that is a great idea. So many options.
Tim, Ian Kitching form George shaped my last board and did a real good job so he is definitely shaping my new one. Try to load some pics of it but i won't work.
bdwqld, think your article changed my mind to just sticking to a quad (I sure love surfing them). Thinking of going your way, Ken!
Thanks again
-
Justin
- Grom (25 or less posts to site)
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- Joined: Wed Mar 09, 2011 5:34 pm
- Location: Canberra
Stuff by McKee is really good. Like his analogy with tyers on a car. Have learnt a bit for his words. However, can't agree with him (unless I have misunderstood) that fins make you go faster. Fins = drag and drag = slower. An expert gutslider can go faster than anyone with fins because they have nothing dragging along under their board to hold them back. Yes, speed is everything trouble is you gotta have fins so it's this tension between having some bite (drive) and planing (slide). What's good about four finners is once you are up on your rail the outside fins come up out of the water and the drag is reduced and you accelerate through your turns. The thruster does this a bit but the rear fin is always in the water pointing in a direction different to the line you are turning on causing drag and slowing things down. So a four finner will always be faster than a thruster. Thuster of course have their advantages as the rear fin tends to moderate things and lessens the constant demand to be responsinve that you get from a four finner.
Fruit Bat - congrats on being a grannd dad and I'll get those measurements to you. - J
Hope this picture thing works...
[_fullalbumimg]29028[/_fullalbumimg]
Fruit Bat - congrats on being a grannd dad and I'll get those measurements to you. - J
Hope this picture thing works...
[_fullalbumimg]29028[/_fullalbumimg]
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bdwqld
- Ripper (more than 100 posts)
- Posts: 236
- Joined: Tue Dec 12, 2006 7:05 pm
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- Contact:
Get rid of the underscores in the front i.e.Justin wrote:
Hope this picture thing works...
[_fullalbumimg]29028[/_fullalbumimg]
[_fullalbumimg]29028[/_fullalbumimg] try {fullalbumimg]29028[/fullalbumimg} except with the square brackets.
[fullalbumimg]29028[/fullalbumimg]
"Start at the Knees Please"
http://neepro.blogspot.com/
http://neepro.blogspot.com/