Quad Concave Body Board Study

What works and what doesn't. Share design ideas, references and contacts for paipo board builders.
PhillyViking
Big Wave Charger
Posts: 70
Joined: Sat Aug 20, 2011 8:38 am

Re: Quad Concave Body Board Study

#41

Unread post by PhillyViking »

While on the comparison roll, A mat has multiple concaves as a result of its tubes. Apparently that contributes to its ability to turn as well as it does. Perhaps I am just trying to make a more rigid mat that will turn harder and take a leash. That would suggest short with a blunt nose.

"More rigid" is a relative term. I am going to retain some in my next board. Ideally, I could flex the rocker on demand but be able to plant a rail. I prefer the feel of some flex as well.
GeoffreyLevens
Big Wave Charger
Posts: 380
Joined: Sat Sep 17, 2011 9:58 am
City: Paonia
State or Province: Colorado
Country: USA
Location: Paonia, Colorado
Contact:

Re: Quad Concave Body Board Study

#42

Unread post by GeoffreyLevens »

PhillyViking wrote: Fri Oct 16, 2020 7:16 amThe mat's squishyiness is a great feature when you do a big air drop to a flat landing.
I used to call my mat "Buffy" in honor of lying on top of Sarah Michelle Gellar i.e. a bit squishy but still firm and nubile er I mean mobile :twisted:
User avatar
krusher74
Big Wave Charger
Posts: 841
Joined: Wed Nov 07, 2012 3:53 pm
City: easkey
State or Province: co sligo
Country: Ireland
Interests: Surfing, vintage cars and motorbikes
Location: Easky, Co sligo , ireland
Contact:

Re: Quad Concave Body Board Study

#43

Unread post by krusher74 »

dk bb.jpg
dk bb.jpg (5.05 KiB) Viewed 604 times
I prefer the pointed nose of my paipo as it give a more relaxed arm position if i hold the nose rather than a bodyboard front corner. I also like the belly i can shape in the paipo nose, i find this aids catching waves and maybe cutes through chop is weak choppy waves. but i have been risind my bodyboard alot this summer and the maing feeling differance is speed and rail engagement, anything nose related would be well down the list of noticed differances.

If you download Akushaper for free you can use it in demo mode, I can then send you the file of my board where you can look at all dimentions.

This is custom bodyboard someone has just had shaped. I would predict a good wave catcher and fast, but not very good at turning
bb wide.jpg
And here is a DK bodyboard, (they are usually 1/2" longer to get the nose) I have tried a coulple and hated the wide point being futher back and the narrow nose that have. when you go forward to speed the board up it not wide enough to support you. Although the one in the pic does not appear to have the wide point very far back.

Oh and very welcome in ireland. plenty of great paipo waves here.
IMG_1535.JPG
User avatar
krusher74
Big Wave Charger
Posts: 841
Joined: Wed Nov 07, 2012 3:53 pm
City: easkey
State or Province: co sligo
Country: Ireland
Interests: Surfing, vintage cars and motorbikes
Location: Easky, Co sligo , ireland
Contact:

Re: Quad Concave Body Board Study

#44

Unread post by krusher74 »

sorry pics are in wrong places
User avatar
krusher74
Big Wave Charger
Posts: 841
Joined: Wed Nov 07, 2012 3:53 pm
City: easkey
State or Province: co sligo
Country: Ireland
Interests: Surfing, vintage cars and motorbikes
Location: Easky, Co sligo , ireland
Contact:

Re: Quad Concave Body Board Study

#45

Unread post by krusher74 »

I was In the shed so thought I would take a few pics, (remember photo make optical illusions, and the bodyboard looks less wide due to it different rail colours)
It's funny that my 42" bodyboard also measures 41.5", they are never as accurate as a shaped surfboard.

so here you can see the little differences in the nose and in overall size.

The V tail was just somthing i did initially as a copy to twin fin fishs, seems to give very good tail hold in steep waves so i have kept it since. (does ding easy thought)
Attachments
2020-10-17 11.20.55.jpg
2020-10-17 11.20.22.jpg
2020-10-17 11.20.08.jpg
2020-10-17 11.19.22.jpg
PhillyViking
Big Wave Charger
Posts: 70
Joined: Sat Aug 20, 2011 8:38 am

Re: Quad Concave Body Board Study

#46

Unread post by PhillyViking »

thanks for the pics and comments. VERY helpful. I will have some comments later.

Please do send the .brd file. I will have to come to terms with installing AKU via Linux on my Chromebook but that will get me going since I wanted to move to CNC anyway. I find building boards gratifying but I am a terrible craftsman and need all the help I can get.

I am going to make two boards .. one with the wegener tuna approach as my safe bet and one with quad concaves as a total crap shoot. Its the only way I can resolve my indecision and get on with it. Agile development is all about velocity of releases not about end all specs.
CHRISPI
Big Wave Charger
Posts: 323
Joined: Sun Dec 28, 2014 2:48 pm
City: Durban
State or Province: Natals
Country: South Africa

Re: Quad Concave Body Board Study

#47

Unread post by CHRISPI »

It can be agonising building new boards being around it for weeks sometimes, knowing all the small imperfection and mistakes in it. I battle with symmetry getting the left and right side profiles exactly the same
User avatar
krusher74
Big Wave Charger
Posts: 841
Joined: Wed Nov 07, 2012 3:53 pm
City: easkey
State or Province: co sligo
Country: Ireland
Interests: Surfing, vintage cars and motorbikes
Location: Easky, Co sligo , ireland
Contact:

Re: Quad Concave Body Board Study

#48

Unread post by krusher74 »

CHRISPI wrote: Tue Oct 20, 2020 4:35 pm It can be agonising building new boards being around it for weeks sometimes, knowing all the small imperfection and mistakes in it. I battle with symmetry getting the left and right side profiles exactly the same
I find even being a prone rider I am goofy, being right-handed i feel better going left with my right hand on the outer rail. So I feel an asymmetrical board could be advantageous, that get you away from having to bother about sides being the same.
Nels
Big Wave Charger
Posts: 232
Joined: Tue Nov 29, 2011 3:58 pm
City: Camarillo
State or Province: California
Country: USA

Re: Quad Concave Body Board Study

#49

Unread post by Nels »

find even being a prone rider I am goofy, being right-handed i feel better going left with my right hand on the outer rail. So I feel an asymmetrical board could be advantageous, that get you away from having to bother about sides being the same.
I'm with you on the first sentence, but you lost me on the second. Maybe I'm missing something (often the case). Doesn't seem like an asymmetrical design relieves need for hand placement.

As for small irregularities in home shaped boards, especially when trying new things, I wouldn't worry too much about them. I've let that halfway crush me in the past, even junked one EPS board because I hated how it looked. Got lazy and went back to wood. I look back and think "Why?" Should have just done the horrible glass job and seen what happened. I wouldn't have paid $450 for it at a shop, but of course neither would anyone else.

In my standup surf life I used to gag when I would read about some pro who was "so tuned in" he could feel 1/4" difference in thickness or width on a new board. Bores me to screaming tears to think about, even if it's true. Let her rip...

RE: earlier comments about back zip wetsuits, O'Neill, and California demand for them...you are welcome. As a geezer myself I can say there is a very large geezer population in California and at a certain point in life one prefers to keep the epic struggles in waves in the lineup and not struggling to put on a wetsuit in the parking lot. Most of us loved the newer materials even if prone riders may not need the superstretchy bits as much as a shortboard surfer. I love the lack of water intrusion. That said, between forking around with the stretchy stuff and then the pullover origami bits for chest zips...mostly our water doesn't get all that cold enough for the hassle. If your equipment keeps you on the beach instead of in the water, you need a change. Under 50 degrees F and yeah, it flips that equation. I just got a 4/3 O'Neill backzip for 2020/2021...

Nels
PhillyViking
Big Wave Charger
Posts: 70
Joined: Sat Aug 20, 2011 8:38 am

Re: Quad Concave Body Board Study

#50

Unread post by PhillyViking »

My favorite board for summer surf this year has my worst craftsmanship. The blank itself was a repurposed use of a previous unusable failure and was not brought back to a perfect blank starting point. I was shooting for the wegener tuna design but because mine was so thin (1") I got in trouble. I experimented with a basalt/innegra hybrid on the bottom. I thought I was going to vacuum bag the 8 oz cloth but was not properly prepared to hold every thing in in place around the sharp rails. The rails were a mess requiring some patch up .. day 0 it looked I had been riding it for a decade with a lot of repairs. But It was my favorite board and the departure point for some refinements in the next build.

Another thread, but I liked the basalt/innegra hybrid weave. My motivation was to make something that could withstand abuse on the shoreline and in the airplane. It looks like it works as advertised. I see some whitewater canoes are made with it.

There is something gratifying about hand shaping but I am considering the next step in automation. I really should say hot wiring as distinct from CNC routing. Greenlight will hot wire cut a blank from a .brd file for $100.95 (blank + cut). https://greenlightsurfsupply.com/collec ... 40-65-long. However, the hotwire just gets you the rocker and profile. You still need to hand shape your rails, concaves etc. But that's still big. Its only $25 more than the standard blanks suitable for Paipos. https://greenlightsurfsupply.com/collec ... e-l-series. I like the folks at Greenlight and it happens to be close to some of the local spots I surf so I can pick it up without shipping fees.
User avatar
rodndtube
Big Wave Charger
Posts: 1095
Joined: Thu Aug 18, 2011 10:34 pm
City: Arbutus Land
State or Province: Maryland
Country: USA
Interests: Waveriding, travel and the Paipo Research Project
Location: Maryland, USA & Where the Waves Are Breaking
Contact:

Re: Quad Concave Body Board Study

#51

Unread post by rodndtube »

When speaking of wide vs. narrow noses the overall width of the board is relevant as well. The Tomo is something like 18 inches as the wide spot, rather narrow. Another thing about that Tomo is the nose concave to actually increase air underneath the nose. Now increased air under the nose in strong offshore waves is one thing that I do NOT want! The Tomo also seems to have quite a bit of through-board rocker but maybe that was an artifact of the one view angle. Back to the original focus of this part of the thread, nose width... there is a happy medium in achieving divergent goals.

When talking about blunt vs thinning of the nose I kept getting thrown off, blunt being a wide and thick nose whereas is thinness being the thickness not the narrowness. So yes, rocker becomes another factor as a 50" board has 25 percent more length than a 40" board, quite a difference (on a standup foot board that is like going from a 8 ft to a 10 ft board).
rodNDtube
"Prone to ride"
I love my papa li`ili`i

"The sea doth wash away all human ills."
-- Euripides.
PhillyViking
Big Wave Charger
Posts: 70
Joined: Sat Aug 20, 2011 8:38 am

Re: Quad Concave Body Board Study

#52

Unread post by PhillyViking »

I was using "blunt" to refer to the lack of a point on the BB nose outline profile. I agree that nose width and thickness are separate attributes to be considered as well. Perhaps it would be more appropriate to say a BB has a squared off nose profile that may or may not have a blunt thickness?

I put a fairly rounded nose profile but thick nose on a recent board build intended for small conditions. I thought that the extra float would get it up on the water sooner for earlier take offs. I wanted to compete with the long boards. Instead, the extra float prevented me from pivoting the board down the wave by pushing the nose down. My future builds that have rounded or more pointy nose profiles will have less thickness so I can pivot the nose down the wave.

A BB with a squared nose profile with most of the nose rocker close to the nose that is also thick would have a tendency to push water at slow speed. I can see that at high speed planing that the nose is no longer a factor as the board is planing on the rear of the board. However, at slow speed a rapid rocker slope on a thick nose would seem to push water. Krusher74 rolled his nose to displace water to the side. The Tomo Vanguard and others use concaves. Adding some length to the nose would seem to afford the opportunity to have a more gradual rocker that would not push water and neither need a roll or concaves.. but based on my experience would need to be kept thin. Its all good and with personal preference, riding style and conditions.

If I have it right, the Tomo Vanguard has minimal bottom rocker and thus faster than the otherwise similar Vader that has more rocker and thus turns better. See https://www.youtube.com/watch?v=AB42PxuTtdI . That seems to reflect fundamentals. Its interesting that the Vanguard is described as having parallel rails that require a narrow width to work. https://www.youtube.com/watch?v=8BDZwESf--M . Wegener reports they had to go narrow width to get the rail to rail turning style of an Alaia to work as well. So, way over my head but it seems all these attributes need to designed as a system that relates to riding style, .e.g. rail to rail vs other turning styles
User avatar
rodndtube
Big Wave Charger
Posts: 1095
Joined: Thu Aug 18, 2011 10:34 pm
City: Arbutus Land
State or Province: Maryland
Country: USA
Interests: Waveriding, travel and the Paipo Research Project
Location: Maryland, USA & Where the Waves Are Breaking
Contact:

Re: Quad Concave Body Board Study

#53

Unread post by rodndtube »

My idea of achieving wave catching competitions with longboards... is to go with more of an "S" deck, something one sees in some of Larry Goddard's boards, e.g., this "S" deck:
https://mypaipoboards.org/interviews/LarryGoddard/DSC02474.jpg
https://mypaipoboards.org/interviews/LarryGoddard/DSC02474.jpg
But maybe with only a little nose rocker and some added tail flip/rocker and fuller center to rail profile and fuller thickness to the tail.
DSC02474[1].jpg
And a slightly wider nose profile.
rodNDtube
"Prone to ride"
I love my papa li`ili`i

"The sea doth wash away all human ills."
-- Euripides.
User avatar
krusher74
Big Wave Charger
Posts: 841
Joined: Wed Nov 07, 2012 3:53 pm
City: easkey
State or Province: co sligo
Country: Ireland
Interests: Surfing, vintage cars and motorbikes
Location: Easky, Co sligo , ireland
Contact:

Re: Quad Concave Body Board Study

#54

Unread post by krusher74 »

Nels wrote: Wed Oct 21, 2020 10:09 am
find even being a prone rider I am goofy, being right-handed i feel better going left with my right hand on the outer rail. So I feel an asymmetrical board could be advantageous, that get you away from having to bother about sides being the same.
I'm with you on the first sentence, but you lost me on the second. Maybe I'm missing something (often the case). Doesn't seem like an asymmetrical design relieves need for hand placement.
Nels
The asym shape would not be there to alter anything to do with hand placement but be a different design to aid the lacking of ability to surf one direction.
This could be a fatter rail etc.
User avatar
krusher74
Big Wave Charger
Posts: 841
Joined: Wed Nov 07, 2012 3:53 pm
City: easkey
State or Province: co sligo
Country: Ireland
Interests: Surfing, vintage cars and motorbikes
Location: Easky, Co sligo , ireland
Contact:

Re: Quad Concave Body Board Study

#55

Unread post by krusher74 »

PhillyViking wrote: Thu Oct 22, 2020 10:40 am I was using "blunt" to refer to the lack of a point on the BB nose outline profile. I agree that nose width and thickness are separate attributes to be considered as well. Perhaps it would be more appropriate to say a BB has a squared off nose profile that may or may not have a blunt thickness?

I put a fairly rounded nose profile but thick nose on a recent board build intended for small conditions. I thought that the extra float would get it up on the water sooner for earlier take offs. I wanted to compete with the long boards. Instead, the extra float prevented me from pivoting the board down the wave by pushing the nose down. My future builds that have rounded or more pointy nose profiles will have less thickness so I can pivot the nose down the wave.

A BB with a squared nose profile with most of the nose rocker close to the nose that is also thick would have a tendency to push water at slow speed. I can see that at high speed planing that the nose is no longer a factor as the board is planing on the rear of the board. However, at slow speed a rapid rocker slope on a thick nose would seem to push water. Krusher74 rolled his nose to displace water to the side. The Tomo Vanguard and others use concaves. Adding some length to the nose would seem to afford the opportunity to have a more gradual rocker that would not push water and neither need a roll or concaves.. but based on my experience would need to be kept thin. Its all good and with personal preference, riding style and conditions.

If I have it right, the Tomo Vanguard has minimal bottom rocker and thus faster than the otherwise similar Vader that has more rocker and thus turns better. See https://www.youtube.com/watch?v=AB42PxuTtdI . That seems to reflect fundamentals. Its interesting that the Vanguard is described as having parallel rails that require a narrow width to work. https://www.youtube.com/watch?v=8BDZwESf--M . Wegener reports they had to go narrow width to get the rail to rail turning style of an Alaia to work as well. So, way over my head but it seems all these attributes need to designed as a system that relates to riding style, .e.g. rail to rail vs other turning styles

One thing that took me a while to understand is that board had a balance point like a seesaw/tettertotter. when you are forward of the balance point you accelerate, behind it you stall. by adding extra nose you are not helping it the way you think you are. You are making the board longer (this does give more planning area which helps) but you are also moving the balance point forward. you now have to be further forward on the board you accelerate/catch a wave. the extra volume out front can be a hindrance till you get forward enough to be over the balance point. Extra volume and planing area will help you catch waves but I think you are concentrating on the wrong place by putting it in the nose. My 26L 43" board catches waves far easier than my 45" 30L board. because in the 45" board I have distributed the volume in the wrong area. (too far forward)

I also think rocker is the most important part of a board. which is why i have my boards CNC cut now so i know the rocker is right, I have tried to replicate the rocker i like by had and with my best efforts i cant get it the same and not the same just ends up with a board that feels worse.
PhillyViking
Big Wave Charger
Posts: 70
Joined: Sat Aug 20, 2011 8:38 am

Re: Quad Concave Body Board Study

#56

Unread post by PhillyViking »

Many paths lead to the same destination. I got on to this BB examination because I watched a friend work the ready fore/aft weighting on his BB.. its has the basic scale and profile of a foamy BB but is fiberglassed so is stiffer and consequently faster. I see exactly what Krusher74 described.

You can see my friend's board next to some of my longer boards in this pic (second from left). On the far right is my 48 x 19" Xylem, next to it is my Bonzer, the far left is my "Slop Hopper" which is just to bulky for me.
IMG_20191015_111339300 (1).jpg
Likewise. once positioned on an a (relatively short) mat one can make ready changes with subtle shifts of weight without shifting position on the mat itself. Longer boards require some repositioning of the body on the board (move forward for trim, back for turns etc.), I do feel that boards that are longer and narrower fit many waves better than short and wide. It may just be subjective experience and background. I recently tried going to 23 inches wide and did not like the experience .. too extreme perhaps but I prefer the feel of a narrower board. Wegener talks about this in some of his posts .. he acknowledges that many shorter/wider designs that use his construction techniques work well but he just prefers the feel of his alaia, Can't argue with that. Perhaps this is a mater of style.

If your style is to stay in one position then the standard BB lengths and moderate width are a good place to be. If you are good with moving around on the board more then something longer and narrower can be a good place to be and has benefits. Everything is a trade off.

As I said, any boards I make going forward that are longer to get those benefits will have thin noses ala Larry Godard's S - Deck. The idea is to get the benefits of a longer nose but still be able to push it down albeit with a shift in body position.

Its also worth noting that at least with Krusher74 and most BB riders they are going finless. Perhaps the BB profile works well for finless. Wegener's longer/narrower boards work finless as well but the riding style is different. I have to think that a fined board can take more length without getting slip / slide.. the extreme of this a a nose riding long board (yes, there are other design features helping).

In any case, I need to experience different designs to know what is right for me at this point in my journey. So I will make one that is shorter and one that is longer. Who knows? I just need to finish up some home improvement projects before resuming my builds.

Yes, Its hard to shape rocker to repeatable spec. I made a 24" inch sanding block that I use with 36 grit paper buts its hard to get right. I will move toward getting at least the rocker and profile cut automated. I am looking forward to seeing the Krusher rocker on the .BRD file he is sending me.
User avatar
krusher74
Big Wave Charger
Posts: 841
Joined: Wed Nov 07, 2012 3:53 pm
City: easkey
State or Province: co sligo
Country: Ireland
Interests: Surfing, vintage cars and motorbikes
Location: Easky, Co sligo , ireland
Contact:

Re: Quad Concave Body Board Study

#57

Unread post by krusher74 »

Your frienda board looks to be in the shape of a jeff hubbard board. and that guy isn't 3 times world champ for no reason.
PhillyViking
Big Wave Charger
Posts: 70
Joined: Sat Aug 20, 2011 8:38 am

Re: Quad Concave Body Board Study

#58

Unread post by PhillyViking »

I see what you mean about my friend's board having a Hubberd profile - see https://hubboards.com/products/hubb-edi ... e277&_ss=r I see that board actually has 5 narrower concaves than the MND's quad. That board has the distinct tail design and the widepoint further forward compared to some of the other BBs I am looking at.
PhillyViking
Big Wave Charger
Posts: 70
Joined: Sat Aug 20, 2011 8:38 am

Re: Quad Concave Body Board Study

#59

Unread post by PhillyViking »

more on Hubb board .. they keep concaves to 18 inches of tail. Some of the others take them more toward center point. That would relate to the idea of pivoting weight forward and back on BB. On a right sized hubb you could lean back to get weight on the channels for turning hard and lean forward to be more loose. Do I have that right? If the channels went too far forward you could not get the looseness and just hard track into the wave.
PhillyViking
Big Wave Charger
Posts: 70
Joined: Sat Aug 20, 2011 8:38 am

Re: Quad Concave Body Board Study

#60

Unread post by PhillyViking »

also at at glance .. seems the hubb has slightly more parallel rails then some others. I have not compared the actual specs but there appears less delta between the wide-point and the tail and the wide-point and the nose width. I like that approach. It seems some of the others are too rounded. It seems like these rails would give you speed when you need it. the concaves would turn when you need it and it is still be loose enough in their forward reach to find the natural arc of the wave .. I am not a trick guy but I see you need to keep it loose enough for that. What do you think?
Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests