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HIpaipo
Joined: 19 Jul 2008 Posts: Location: Oahu,Ewa Beach
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Posted: Tue Dec 08, 2009 8:59 pm Post subject: What produces Speed? |
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Just wondering, what produces speed? Do things like rocker, concave(s), flex, etc... help with speed? Or perhaps the size or flotation of the board??? _________________ " NO SCARED UM, GO GET UM! " |
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mrmike
Joined: 06 Sep 2007 Posts: Location: coronado, ca
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Posted: Tue Dec 08, 2009 9:30 pm Post subject: |
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you just asked the ultimate question and the answer is 42 for me flat is it, with nothing hanging on the bottom like fins to slow you down MRMIKE _________________ PAIPO ON
blog http://mrmikespaipos.blogspot.com |
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Soulglider
Joined: 04 Feb 2008 Posts:
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Posted: Tue Dec 08, 2009 9:58 pm Post subject: ghhfg |
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flat is fastest. is fast all you want? flat an thick so the board is on top of the water is really fast. not the best for turning etc. as design stands right now, its a game of compromise. bottom, rail, outline, width etc all play a part in the board. to much of anything and you give up something. mikes boards are fast. my boards are fast. my fins are only 1/8 thick. feels finless but have drive. no one answer...i love my finless boards, i love my finned boards. mood plays a big part! _________________ soulglider
http://soulgliderpaipo.blogspot.com |
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HIpaipo
Joined: 19 Jul 2008 Posts: Location: Oahu,Ewa Beach
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Posted: Wed Dec 09, 2009 2:30 am Post subject: Re: ghhfg |
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[quote="Soulglider"] flat an thick so the board is on top of the water is really fast. not the best for turning etc.
I was thinking about this, or maybe making the board bigger, to hold the rider up....hmmm, IDK _________________ " NO SCARED UM, GO GET UM! " |
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bgreen
Joined: 20 Feb 2004 Posts: Location: Qld. Oz
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Posted: Wed Dec 09, 2009 5:34 am Post subject: |
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HIpaipo,
A complex subject. Doc's interview has info on design. Flat wood bottoms certainly are fast. A more buoyant foam board will plane better than a less bouyant board but in bigger, more powerful waves will sit higher in the water and skip like a stone when going real fast. Jim Growney has emhasised reducing the wetted area.
When you see Harry, ask him what he thinks. Larry has said Harry makes some of the fastest boards he has seen. I believe they have smallish concaves.
Search Swaylocks - some sample posts
Re: [beerfan] Really round rails on my board, should i add ...
Re: [PlusOneShaper] Hard Numbers on Flex demystify "flex ...
Re: [BenjaminThompso] Hydrofoils and Lift
regards
Bob |
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HIpaipo
Joined: 19 Jul 2008 Posts: Location: Oahu,Ewa Beach
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Posted: Wed Dec 09, 2009 10:31 am Post subject: |
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The Harry OG-AZN was talking about in the interview? That Harry has an interesting board- two bodyboard style channels close together near the back of the board, and maybe a little spoon in the nose, yet it is all made out of wood! How did he do it??? _________________ " NO SCARED UM, GO GET UM! " |
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bgreen
Joined: 20 Feb 2004 Posts: Location: Qld. Oz
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Posted: Wed Dec 09, 2009 2:42 pm Post subject: |
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HIpaipo,
Yes it is the same Harry. How does he do it - ask and he may tell you? If you are going to post anything he tells you, it would be a good idea to get his permission to do so.
e.g "I asked on a paipo forum about speed and your name came up, mind if I pass on what you have to say"
Bob |
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OG-AZN
Joined: 27 Jul 2009 Posts: Location: Norcal
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Posted: Thu Dec 10, 2009 12:35 am Post subject: |
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On Hawaiian style paipos, 0 or very slight rocker & a balance between stiffness & flex seems to work best. Think about what works well on a bodyboard. Also, a flat bottom w/a smooth "roll' transition from bottom to rail; since it's all about planing. Since riding a ply paipo is so much like bodysurfing, body/ arm/ leg placement seems to have just as much to do with performance as board design. |
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HIpaipo
Joined: 19 Jul 2008 Posts: Location: Oahu,Ewa Beach
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Posted: Thu Dec 10, 2009 1:17 am Post subject: |
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Will ask Harry if I see him.
Just thought of another possibility. Maybe you need different boards for different conditions? ie- one for slow, wall type waves and one for steep, dredging, hollow waves. _________________ " NO SCARED UM, GO GET UM! " |
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Soulglider
Joined: 04 Feb 2008 Posts:
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Posted: Thu Dec 10, 2009 8:52 am Post subject: acs |
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always more than one board. it gets boring doing/riding the same thing for every situation. sometimes i like finless on the same wave i like to ride finned boards. having fun is paramount and riding different stuff makes you a better surfer... _________________ soulglider
http://soulgliderpaipo.blogspot.com |
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surffoils
Joined: 12 May 2007 Posts: Location: Gold Coast, (finally), Australia
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Posted: Thu Dec 10, 2009 3:41 pm Post subject: Re: What produces Speed? |
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HIpaipo wrote: | Just wondering, what produces speed? Do things like rocker, concave(s), flex, etc... help with speed? Or perhaps the size or flotation of the board??? |
IMHO.... Of all the forces involved (wave speed, lateral speed) I believe that gravity produces the most speed.
A paipo or bodyboard is pretty much a static load as the boards cant be 'pumped' like a surfboard so it needs to reduce all forms of drag and emphasise any hydrodynamic benefits from features like aspect ratio and surface area/contour.
Every control surface is a drag surface, and we need control surfaces to give us lift and direction so boards do not necessarily need minimal surface area to reduce drag. There comes a point where lowering the surface area will increase drag but its different for planing craft and hydrofoils, Ive found.
One thing I do believe to be true from all the boards and experiments Ive done is that we are all currently riding very close to the highest possible speed.
Ive tried flat, curved, channels, wide, thin,tunnels, hydrofoils of all shapes and they all return a range of GPS speeds that are similar. Another observation is that the max speed is more regulated by the size of the wave than the craft and thats where gravity comes into the equation.
But these are only my observations so theres every chance Im wrong.
As for board design... |
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kernowpaipo
Joined: 21 Sep 2008 Posts: Location: Cornwall UK
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Posted: Tue Dec 15, 2009 8:09 am Post subject: |
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my paipos are fast - I normally try and create a bottom concave, however adding fins has been akin to turning the dial up to 11 - real down the line speed.
Local booger on a finless balsa paipoglide paipo at Porthmeor St Ives
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kernowpaipo
Joined: 21 Sep 2008 Posts: Location: Cornwall UK
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Posted: Tue Dec 15, 2009 8:12 am Post subject: |
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my paipos are fast - I normally try and create a bottom concave, however adding fins has been akin to turning the dial up to 11 - real down the line speed.
Local booger on a finless balsa paipoglide paipo at Porthmeor St Ives
photo: Mike Newman - Ocean-image.com
www.paipoglide.com |
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bgreen
Joined: 20 Feb 2004 Posts: Location: Qld. Oz
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Posted: Tue Dec 15, 2009 3:11 pm Post subject: |
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Andy,
Great shot and interesting to hear the fins made a difference. Was the board in the photo the standard board that you make?
A potential interview topic.
regards
Bob |
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Soulglider
Joined: 04 Feb 2008 Posts:
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Posted: Tue Dec 15, 2009 3:23 pm Post subject: |
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bob, fins are "drag" but, if a plane didnt have a tail would it go faster than the same plane with a tail? fins play a huge part in the way a board works. my finless boards, that work the way i want them to, have concaves in them. deep enough concaves that you can consider the tail rails work like fins. whats faster, eels or just about any fish with vertical fins? _________________ soulglider
http://soulgliderpaipo.blogspot.com |
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