https://www.facebook.com/groups/paipobe ... 785555080/
I’ve made one of those in paulownia with a big single concave’ goes like hell but it needs to be punchy surf.
Bill Wurts
Used these in 2-4 ft, spilling to plunging waves. At 22” wide X 48” long, they catch waves easily. Flat, rectangular planing surface is 18” wide. With a flat, rectangular bottom they go fast.
Conrad Elliott
yeah it was good haven’t used it for a while have to wait for some good surf and use it again. I’m a bit obsessed with the kneeboard at the moment.
Bill Wurts
This is kind of a kneeboard/bodyboard hybrid. It has a lot of volume at 3” thick, which I like. The planshape outline is derived from a slightly modified 5-5 Lis Fish template. Planshape was derived using a 40:60 (front:rear) length distribution around the wide point. Low res phone camera photo of chamfer bottoms, with and without channel. Phone angle distorts image shape outline.
Thomas Haugh
Definitely on the right track with Lord's planing hull aspect ratio ideas. Sims took Lord's ideas and added the bottom rear exit concave to relieve the bottom pressure Lord described. He also added twin fins. These original ideas are all circa Late-40s to Early-50s. Standing on the shoulders of giants...
Bill Wurts
The channel is designed to create low pressure (suction) — basically a low drag (finless) fin. Bob Simmons was a true innovator.
when you relieve “high pressure “ you create “low pressure “. Low pressure reduces friction and consequently increases speed. “Suction”, in my opinion, would increase friction.
Bill Wurts
I believe the relative drag of the channel is much lower than that of a fin. The orientation of the channel curves has minimal disturbance on the boundary layer. The channel holds the tail to the surface of the water — draws water into the channel — for directional control (tracking).
The cross-sectional flow area of that channel increases as the sidewalls flare outward and depth increases -- both in a rearward direction (while remaining recessed). This causes the static pressure to drop, drawing water into the channel without causing substantial drag effects. The channel avoids form drag and flow separation. The channel increases the flow rate of water through it while not disturbing the boundary layer.
Larry O'Brien
Soft board materials?
Keith Usher
have you surfed it, did it "work"
Bill Wurts
Have ridden it in 2'-4' spilling and closeout plunging waves. Caught waves easily. Felt fast. Seemed to hold the brief unbroken sections of closeout wall well. No problems tracking transversely in front of the whitewater. Hope to get a better idea of performance at the Bodyboard event at the Waco wave machine in October -- consistent size and form.
Keith Usher
"spilling and closeout plunging waves" that's some new surf lingo on me!
Bill Wurts
From oceanography terminology I guess (I'm a retired aquatic scientist). Spilling = top tumblers (mushy). Plunging = pitching, steep wall, hollow. Closeout is standard surf meaning -- whole wall collapses nearly simultaneously.
Bottom Chamfer Blank
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https://www.facebook.com/groups/paipobe ... 265650080/?
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Nice little pocket. Don't be a clone, ride prone, where every wave is overhead.
Keith Anderson
yep and expectations not as high
Tony Ahrens
I know that dude pretty well
Bill Wurts
We got along pretty well. Very focused but a free spirit — traveling extensively in a RV with his Doby. Several inches over 6-feet tall.
Tony Ahrens
I know I sold him that RV at the wedge in California
Chad Stickney
20 October 2023
https://www.facebook.com/groups/paipobe ... 576330080/
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It holds in the pocket well
Bill Wurts
The design objective was/is a finless fin.
Next model will be the twin channel.
30 October 2023
https://www.facebook.com/groups/paipobe ... 715535080/
Bob Green
Looks like the rider should have been kicking hard to get into it rather than waiting to be picked up by the lip.
Bill Wurts
The rider is me. And Yes. The take-off is strange and very specific. All of my surfer instincts fought against the correct method. I’m too used to facing the oncoming wave and spinning at the right moment. To top it off, I was borderline hypothermic — daytime highs in Waco, TX should have been mid-80s on 10/15/2023.
Keith Usher
what temp was it, they declared a yellow weather warning for high temps here in ireland this summer and it was 80f that day. You don't have a hard rail on a mat to drive across a steep wall like that.
Bob Green
I think the board might be like this one - https://www.facebook.com/groups/paipobe ... 785555080/
Bill Wurts
Close. It's made from 6-pcf XLPE. The board is like this one (below) with rounded top rails to around 42% of board thickness. Also rounded top and bottom edges of the nose section in front of the chamfers.
There were 66 days above 100 F (29 consecutive days) in Waco, TX this summer (2023). Highest temp was 110 F (25 August 2023).
Temps for both morning sessions in Waco were 46-52 F (10/15-10/16) with strong, gusting north winds — sudden unseasonable cold front upon arrival. Pretty much the same for the 6-9 pm evening sessions.
Daytime highs are normally 80-85 F for Waco, TX in mid-October. That’s what I came prepared for (brought a 1.5 mm, sleeveless shortie and a neoprene sweat vest in case air temps were in the lower 70s).
That’s not a mat. It’s my channel-tail, chamfer-rail XLPE prototype. This prototype can hold a wall (second wave in video).
https://vimeo.com/876106440
Chad_Stickney_Tube
Keith Usher
interesting read of their website that the water temp there unlike the sea seems to be drastically/quickly affected by air temp. Today it's reading 60f water temp, which I would be cozy in a 3/2. I dont know what your 46/52 day brought the water temp down to but if it was in the air range that's 5/3 6/4 territory!
Bill Wurts
Basically the wave/surf pool is a shallow pond (around 0.5-1.0 ha). Shallow ponds cool down fast — especially with strong wind and continuously breaking 4’ waves. I believe Jay Reale was wearing a 4/3, chest-zip, full suit (no hood). After I got out of the water, I put on a winter ski jacket, over a polar fleece vest, over a long-sleeve thermal shirt; wearing sweat pants over cotton shorts. I was still shivering. The cold, gusting, strong north wind was the most brutal factor.
Keith Usher
it must have been cold for Jay to have a 4./3 on, he has very low body fat, and I have seen him using a 5/3 and hood in cali water i would be happy in a 3/2 all day.
1 December 2023
https://www.facebook.com/groups/paipobe ... 165575080/
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https://www.facebook.com/groups/paipobe ... 348435080/
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I recommend viewing it in "full-screen" mode.
Jay_Reale_Intvw_Waco-10-16-20223
Bill Wurts
42- and 48-inch variants of the Lindsay Lord Hybrid concept -- with my Coanda Channel.
with your scientific approach, have you ever considered recreating. the Lord experiments? As I recall, his strain gauge and flow tank contraption was quite simple and the 'hulls' he used were likewise non-complex. The 2 hulls pictured above appear to have pretty different width vs length ratios.
Keith Usher
The lord experiments worked out what had lease resistance/drag in a straight line, (or was that Simmons) but as surfers we also want to turn. The more you make a perfect lord board the less it wants to turn, so it is all about how much of what you want in your pie!
John Morris
his 'hulls' had no curvature: straight, flat bottom, parallel, square rails, blunt front and back. His findings are often cited, but it's not clear to me how applicable they are. So I wonder what an updated set of tests with some hull shape would reveal.
Agreed, but look at the variety of hull shapes out there. It certainly appears that there's no single design element that's essential for a board to perform.
Bill Wurts
Bodyboard hulls are intended to be flat in the rear section — nose kick only. The Coanda channel has to be within a flat surface. Will not work within a tail rocker curve. Width is the same — planing surface and board — for both boards pictured (and they measure the same in the photos), mostly just optical illusion from the different lengths. Planing surface aspect ratios are about 0.4 and 0.46 for the 48” and 45”, respectively. Would love to test but don’t have boat, tension gauges etc. I’m fairly certain the Coanda Channels will alter the Lord planing performance relative to the same boards without the channels.
The difference is, I added a parallel edge planing surface while maintaining more traditional Lis Fish or bodyboard curves in the planshape. Curved planshapes allow the rider to set a rail/keel. The Coanda Channel holds the bodyboard tail and hull in the correct position on the wave, allowing the rails to engage for better tracking and turns. Rail profile also adds Coanda Effect.
John Morris
First I've heard of 'Coanda Channel'. But my first two paipos had trouble holding on a steep face and too much volume overall. They also had near zero tail rocker. So I modified them with an 'escape hatch' which I think is Matt Biolos' name for the feature . Mine were relatively shallow and in cross section created a Vee. One had straight sides, the other was curved like yours. I believe they helped with hold and other aspects of the boards' handling.
Bill Wurts
The “Coanda Channel” is my patented creation — designed around the ‘Coanda Effect.’ The Coanda Channel (CC) bottom surface is flat but curves toward the deck, creating indirect tail rocker within the channel. The sidewalls and bottom of the CC create an area of low pressure in the tail, holding the tail in proper orientation to the wave — finless fin. The boards pictured have a lot of volume at 3” thick and planshape 22” wide. CC max depth is 1.75”.
Bob Green
https://www.reddit.com/.../ryan_burch_l ... _video.../
From the surfing community on Reddit: Ryan Burch Lord Board Video. For the hipsters in the sea.
Keith Usher
Ryan did hardly any shaping on that block of foam. I surfed with him in G-land and took this video of him, a could of waves later he snapped it.
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Ryan burch G land
Bill Wurts
The catalyst for my Coanda Channel was a tail channel I saw on Swaylocks in 2010 (photo below; Mike Daniel ~ 1990). Mike mentioned a shallow draft boat hull that had a similar concept. (Many years later I saw that concept in ”tunnel hull“ Jon Boats.)
After a few years of internet searching, I discovered the Coanda Effect.
Learning about the Coanda Effect led to my first Coanda Channel design. https://forum.swaylocks.com/t/less-fins/47777/85
- Wurts4JanDaniels.jpg (11.53 KiB) Viewed 152 times
His surfing ability makes riding it look easier than it would be. Prone would likely be easier than standing - just shows you can surf just about anything.
Keith Usher
I have a subtle open single channel on my own board.
Bill Wurts
After I built my first Coanda Channel, I discovered there was also the Bing Auga around 1969/1970.
Bill Wurts
https://forum.swaylocks.com/t/lindsay-lord-hybrid/78725
Keith Usher
"Agreed, but look at the variety of hull shapes out there. It certainly appears that there's no single design element that's essential for a board to perform." "Perform" is an interesting concept in surfing. Its not like we have a lap time to see which is the best-performing racecar. Every board I have ever ridden will get me along a wave. But until you ride a better one you really don't realize how bad another is actually performing. The design elements for what goes into a shortboard for a Pro Surfer and now pretty narrow. (performing to me is moving/turning to the part of the wave I want to be with the least effort/struggle, on high-quality waves)
John Morris
I'm with you. I stopped shaping my own boards after 20 or so after I rode a couple that worked so much better. Of course, the shapers of those boards were shaping more in a week than I did in my 'career'. My boards need to perform like yours only in medium quality waves and with an old battered body.
Bill Wurts
Pretty sure the video is too long to direct load into FB. I can probably upload it to YouTube but with some loss of image resolution.
Bill Wurts
On Youtube now. Use full screen mode. Adjust volume: https://youtu.be/z6gWiWJ0X_A?si=d47f7FwUUkOU7rnv
Jay Reale Intvw Waco 10 16 2023
Keith Usher
did he have a go?
Bill Wurts
Nah. A member of the group suggested it. But the look on his face suggested to me that he likely viewed the suggestion as an endorsement of my design — he has his own BB line. My comment about his response sort of gave him an out.
Keith Usher
It was my boredom with the lack of new designs in bodyboarding that led me to Paipos 10 years ago to give my own ideas a go. bodyboards all come out of one factory in Indonesia and the Line he made is just stock boards from that factory. (it's probably a much better profit margin for him than selling other brands boards so adds to his business) The pro bodyboard design is very well honed and has been for 20 years so with its construction limitations it not really got many places to go, the same as the standard 5.10 performance competition stand-up board It does amaze me people's disinterest in trying something new though, i once bumped into Ryan hardy (pro bodyboarder) in indo and we had a board swap. He gave my board a good go and seemed generally interested. but in general when a bodyboarder in the water with me has asked about my board when offered the chance at a board swap for a couple of waves most have declined.
Bill Wurts
Because it was so cold, I gave Chad Stickney a good bit of my riding time. As a result, he offered to ride my 42” board for me. After the first few rides, he came back enthusiastic, saying that he caught 3 tubes and that it rode good prone. Vicki Reale caught one of those rides on video. And Tony Prince shot a great still photo of Chad “covered up.”. As with surfboards, it’s my observation that BB design has become variations on the same theme. I think BB construction tech has pretty much stalemated the evolution. Standard, modern surfboard design software and CNC shaping machines were unable to design and cut my channel. A gifted garage CAD designer I met on Sways was the only one who could do the CAD work and also did the first successful CNC cut. Only 2 of around 20 CNC shaping companies I contacted could make a clean cut of my channel, chamfers and planshape. However, I have since invented a ”3-piece blank technology” that allows very accurate hand-shaping of the Coanda Channel. My planshape evolved from the Lis Fish kneeboard planshape. I wanted a hybrid bodyboard-kneeboard concept. If I live long enough, I plan to make (or have made) a “finless Fish” with my channel in it.
Keith Usher
Bill Wurts What I would do next is shape an identical board without the channel so to can ride both and compare. What are you trying to gain with this design? Also if you want CNC go to https://www.facebook.com/L41Surfcraft/ he was a CNC machinist before they were ever used on a surfboard and pioneered their use
L41 Surfcraft
