First Quad Longboard - Is My Design on Track?

General Discussion
1

I have been asked by a friend to build him a 9’ quad longboard. It will be my first quad build. I have done some research,put some info together and ordered the materials but would like some experienced feedback and constructive criticism before I start shaping.

My friend has only been surfing for 2 to 3 years but he has shown impressive progression and determination. He weighs approximately 14 stone / 196 lbs. He learnt to surf on a SUP and spent much time on 9’7" x 28" x very thick SUP. He then progressed to a 10’ single fin nose rider which I think has bit of volume to it. Now he is no longer content to just glide in a straight line but wants to go shorter and looser. He has now set his heart on a 9’ quad that will enable him to explore the wonders of radical turning. However due to his experience of SUPs he is still a bit dependent on volume especially as it enables him to knee paddle and generally paddle easily. He had initially wanted to buy himself another SUP - a Surftech Gerry Lopez 8’11" Lil Darlin but fortunately I convinced him that all that width and thickness was a waste and a hinderance to ones surfing and pocket unless you plan to buy a paddle to go with it and stand up on it, and also that handmade custom built is far better for all concerned.

MATERIALS

US Blank 903Y - 9’3" x 25 1/8" x 3.5"  Nose rocker 4 3/8" Tail rocker 3 1/2"

2 layers of 6 oz cloth on deck, single 6 oz on bottom ; RR Epoxy Resin

Fins: Futures Stretch Quad Set(for mushy surf)

Height: 4.39 in
Base: 4.34 in
Area: 14.52 sq in

Rear Fins: 400 Quad Rear
Height: 4.00 in
Base: 3.89 in
Area: 12.41 sq in

Location, toe and cant to be determined

PROPOSED DIMENSIONS

Length 9’

Width - widest point (centre?) 23 - 23.5"

Nose width - 18"?

Tail width - 15"?

Tail block - 7"? - Square?

Thickness - centre 3.25" min.

Thickness - nose ?

Thickness - tail?

Nose flip

BOTTOM DESIGN

Single concave to double concave to vee -

Slight roll in first 12 to 20 inches of entry; shallow single concave increasing in depth to maximum depth (what depth?) about halfway from wide point to rail fins (front rails); double concave (what depth?) begins at or near this spot and carries through rail fins; double concave decreases quickly through the fins; double concave transitions to vee in
last 6 to 10 inches of tail (How much exit vee at tail block?)

RAIL DESIGN

Sharp downturned rails - upturned in nose progressing to 80/20 downturned mid to full sharp edge (tucked in edge?) from rails through to tail.

Chines? Would these on the outside of the concave enhance water release and speed and if so what width and angle?

FOILING

In order to provide extra volume dome the deck down to the rails, keep some thickness in centre of tail (but thickness at the tail rails but enhance bite on turns, and nose (a bit less in the nose to reduce swing weight?)

There are no doubt different points of view but my main focus is for my first experience is to make sure that I get the concaves right because it is my understanding is that if I dont it will kill the board. (all this is presuming that single to double concave in a quad is they way to get to increase lift and speed.)

I realise I have put a lot of information here and I have asked a lot of questions but if I am generally straying off the track and someone can point me in the right direction I would be grateful. I will continue to do research. As I said I dont want to leap in and make mistakes but I need to start shaping in the next week or so.

Many thanks

 

2

From what I've seen, some of the shorter SUP designs would work fine for a big guy.  I've shaped big longboards as wide as 27"-28" and as much as 5" thick and they worked fine under the right rider.  I've also shaped bellyboards as wide as 29" - again, to good effect.

 

3

Hi sabrina,

I’m seeing a lot of contradictions here.  First, your friend is has been surfing about 3 years.  Unless he’s extremely talented he is a still a novice and won’t be exploring the wonders of radical surfing for a couple more years of serious effort.  Especially, on a 9 foot long board and fins you describe for mushy surf.  Second, you give a lot of data and information.  But, is your friend really good enough to notice and furthermore, as a hobby shaper,(checked your profile and probably wouldn’t be asking these questions if you were a pro.), Can you deliver the board as described with this degree of specification?  I’m not trying to be an asshole, just wondering because after shaping and glassing about 80 boards I could not deliver the goods to this degree of precision and if anyone asked me to I would suggest they go to a pro.    Mike

4

Wow, That is a technical bottom and build.

For a high performance long board, for your firiends radical turning experince, you may need to tweak you outline a bit to start.

23.5" wide you probably want to increase nose width by one inch- maybe more.  After you draw the outline on the blank, I woud look to see what the 15" tail  draws out as. Might want to take down to 14".

Your numbers are more of a log style board and I think you want wide nose to narrow high performance quad tail.  I would have an 18" nose with 22" width. So you need to proportion your nose and tail to your wider board.

Under 200 lbs and average surfing skills, I think you have too much foam in your baord. I would keep it under 3" thick beca;use of your extra width. The summer surf here is ankle to shoulder high, and probably the same for you. If your friend is in terrible shape, maybe the extra foam would be helpful to him. It won’t help him in the slashing department

Bottom design. Keep it simple- flat works great, chines are not necessary.  Sharp rails 20" up from the tail.

Quad set up. Use the Mckee forumla. Takes all the quess work out of it.  Thruster set up works great also.

Built a similar board for myself with an equivalent clark blank. I will send you a pic in the next few days.

Have fun with your build.

aloha

5

would suggest a round tail or diamond for pivot,… tail rocker, fin placement and templates are critical… tail planshape and curves make or break the performance of the quad longboards from my experience…vee or dble concave is a must at that width, chines may be an option too…but with right planshape, bottom contours and rocker, they arent vital imo…but all the above will depend on how much manouverability you want from the board…

6

Make it a 5 fin add a center box, if it doesnt work well as a quad…ride it as a tri or a single.   Options… dont limit the board

7

Go to the link   What is the difference gonna be? and check out the 8 footer by ACE. That thing is the tits and would work great as a quad. Long enough, wide enough and thick enough for under 200 lb surfer. Probably extremly rippable too. You could use the blank you already have too.

Back to your design.

Here are pics of my glassed yesterday longboard 9’3" x 18" nose, 22 1/2" wide x 14" tail and 2 7/8" thick. I sanded it today and will final coat it this week.

I think your 18" nose and 23.5" width will look strange. I definately think you need to widen the nose and maybe take a 1/2" off the tail.

Please check out Ace’s 8’ board.  No disrepect to your plan, but that really would be a step up to the goal of more manueverable surfing.

 

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Radical was my choice of word not his and in hindsight is too strong - just more significant turning. Yes good point he is not going to notice all the finer features at his level of experience. The proposed specs are mine. He is totally trusting me to produce the right board for him. I have even convinced him that a decent 9’ quad can have more than enough volume for him. Can I deliver? Well I have only made a dozen boards to date and none like this but believing that if I do my homework and work carefully I can produce a board that he will be more than happy with. It is a challenge about which I am excited as well as nervous but its an opportunity to progress my designing and shaping. As I said the desire for precision comes from me not him. My experience to date tells me that I can only do so much thinking and designing and then I must then just trust myself and make it. But generally how difficult is it for a garage shaper to make his first quad with the concaves that I have described? Respect that you have already made 80 boards. Have you made one of these Rooster?

9

BB30, very nice.  and nice job on those balsa rails, particularly the nose.  I don’t want to hijack this thread, but I would love to hear how you wrestled that balsa around the nose.  It is so much easier to use HD PU, that I stopped doing balsa rails.

Ilovesabrina, if that is your real name (ha), I think Rooster has a point.  Sounds like this is becoming a big complicated design project for you, not for the customer.  Which I can appreciate, since I’ve been there too.  I am more of a copier than a designer and even when I venture out, I don’t get too far afield.  There is a reason most boards look like most boards.   There is nothing wrong with a flat bottom. I have ridden boards with complicated bottoms and honestly can’t feel much of a diff.  McKee has provided the fin settings on a silver platter for us all.  It would take decades and a lot of money to argue with his numbers.  I send him $5 in the mail every time I build a quad.  (Actually, I haven’t exactly mailed the check, but I will.  As soon as I write the check.  And find a stamp.  And get his address.).  Be sure and post some pics.

 

all the best.

10

Thanks bb30. Yes I spoke to my mate again and he does not want to reduce the width so I will consider your nose and tail measurements when I do the template shortly. Its got to look right in plan. Bottom design flat - tempting but then there’s the challenge of doing concaves and what they might offer. I’ll meditate on that.

I have found Mckee’s formulas and worked out some placement measurements for the fins. Still to establish toe and cant.

Yes I must make sure I dont end up with a quad log.

Terrible shape? No. He’s pretty fit. I think the volume issue is a security one from which he can be weaned.

11

Yes diamond tail seems more sensible than square.

Critical. Make or break. These are words I have heard before and have filled my inexperienced shaping heart with fear but with knowledge and guidance I would like to deal with that fear. Or do the wiser think I am not ready yet?

Manouverability? No its not going to be excessive at this stage.

Probably best that I try and do a design on akushaper and post it here. I will be printing out the template anyway.

12

Yes diamond tail seems more sensible than square.

Critical. Make or break. These are words I have heard before and have filled my inexperienced shaping heart with fear but with knowledge and guidance I would like to deal with that fear. Or do the wiser think I am not ready yet?

Manouverability? No its not going to be excessive at this stage.

Probably best that I try and do a design on akushaper and post it here. I will be printing out the template anyway.

13

Love your board and I love ACEs. This is the sort of board I want for myself. The problem is that my mates are ending up with better boards than me. The next project after this quad has to be a board for me. Yes going to punch in all these suggested dims and see.

14

Hello Greg Tate. No my name is not Sabrina, I just love her.  Yes you and Rooster and have hit the provebial nail on the proverbial head. I’m making it too complicated. This is a personal failing that often overflows in my board building and many aspects of my life. I tend to get bogged down in the detail. Cant see the wood for trees. Etc. From this I must break free. Currently I do favour the flat bottom (only on boards mind). It would be a safe haven for me. What is this thing about wanting to shape a single into double concave? Am I trying to prove something to myself and the world? Am I just trying to complicate my life? Am I asking too many rhetorical questions?

A donation to Mr McKee seems a worthy gesture.

Yes there will be pics.

Cheers

Mike

15

This is my first plan outline attempt.

16

That outline looks clean to me.  I wouldn't change a thing.

17

I agree with John, looks nice…

18

Thanks guys.

Any recommendations on maximum depth of concave and vee?

19

I'm no expert  =) , but I have a 9' longboard.  Single fin, no concave, but I put V out the tail.  

The picture makes it look a bit exaggerated I think - the stringer is about 3/16ths inch lower than the rails, and it works very well, the board turns nicely when stepping back on the tail.

20

Thanks Huck yes this was about the amount of vee I had in mind. Lovely looking board by the way. I’m still not convinced that my proposed board requires concaves. Im due to start shaping tomorrow and have given it a lot of thought. This board will be ridden in a lot of weak mushy surf where surely a flat bottom will funtion better than a concave one. I would think concaves in lumpy surf would create drag and slow water release especially on turns? Rolled nose/flat/vee tail surely is the best for all round conditions.

I think I shall go to be bed just now, wake up in the morning, go to my workshop and trust my instincts.