V bottom VS single concave VS double concave VS Flat

General Discussion
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So for a backyard shaper I shape a fair bit. 

But…I wanted to find out more about “V” Bottom boards.  and Flat bottom boards.

I have been trying to refine my technique lately.  Recently I have been throwing the kitchen sink at the boards I make. 

The last two had a chined rails leading to concave aross the hull and leading to double concave with a camel hump forward of the fins in a 2 +1 set up.  

The overall outcome was junk.  The boards had trouble breaking surface tension and while they surfed…they also litterally sucked to the water.  I belive mostly due to the lower rocker profile I designed into the blanks and not paying attention by leaving simply too long of a flat spot between the rails.

I have a Larry Mabile twinzer that (while I don’t ride often due to shaping my own boards)  The thing flat out flies. 

It’s a V bottom leading to moderate heavy double through the fins. V comes to approx 3/16" off the rail leading to hard edge at tail.

I’ve hear about V bottoms before and experienced them.  But as I have only shaped one for a friend (he loves it)

I wonder about it for waves of size (trip to nicaragua soon)

I was thinking about doing a 6’8" low entry rocker.  rocker profile  4.25" / 7/8"@1’ / 0"@ 3’6" mark (2" forward) 1" at 1’ off tail and 2.4" @ tail.   Wide point 2" to 3" forward and round pin…

Thoughts on V bottoms and should I keep it V through out or double concave it through the fins?  Or Flat bottom?

(had a Mark Richards that was super controlled quad that was basically flat…such a good board. 

Thoughts?  V? flat? or mild concave, leading to double.

(the pic is the same board that I made for a friend…went great except this one is super flat, heavy V in the nose, mild concave center, double out the back…it bogged when I stepped to the front.  It was strange…but it went amazing but also had it’s issues…

I feel I need to simplify.  standard tried and true specs and concepts. Something that I can count on delivering in waist high to heavy possibly DOH. [img_assist|nid=1075650|title=the gibbon|desc=|link=none|align=left|width=230|height=306]

 

 

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There are two rockers in a board, stringer rocker (as previously mentioned) and rail rocker.   In a flat bottom the two rockers are the same.   With a single concave, the stringer rocker will flatten while the rail rocker remains the same.  With Vee, the stringer rocker is the same but the rail rocker increases as the bottom rail edge will be higher than stringer (deckside up on a flat surface).  With double concaves (or channels) the two rockers are still the same, but there’s another rocker (flatter) established inward from the rail (at the centerline of each concave). Vee’s and concaves are about how you want to tweak the relationship between these two rockers, because you are in effectively altering volume from the stringer out to the rails.  Where these two rockers blend along the bottom rail edge is also important but that’s relative to outline and rail contour.   In general, for small mushy waves a low rockered flat bottom with very slight contours works best, and turning control is more a function of the fin setup.  For bigger and faster conditions, stringer rocker is increased and more Vee is needed for turning control.

1 Like
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I asked the same question here long ago. Some men far wiser than me, said get the rocker right. Bells and whistles are less important. 

I now know my rockers inside and out and my boards rip.  

Don’t forget, bells and whistles alter rocker. How will you ever get it sorted?  Stick with flat bottoms for now.

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Dwight is right

Rocker is most important.  Stringer rocker is most important of all.

If you change the bottom contour, and add concave, does it flatten out the stringer rocker?  No.  It can just as easily alter the rail rocker.

A few thoughts on bottoms.

  • Concave lets you pump for speed, while flat to hull does so less.
  • Flat or hull have a higher top speed, but pumping a concave will get you to top speed faster.
  • Concave turns easier/ looser.
  • Flat to hull is more stable.
  • Concave gets caught at the lip more.
  • Flat will get you down the face faster.
  • Flat to hull lets you angle the take off, while a concave taking off aimed down the line will tend to hang at the lip more, and catch your outside rail on angled takeoffs.
  • Vee is basically a very long and shallow fin, and so it makes the board track more.
  • Beveled bottom rails makes the flat area narrower, so you can put the board on edge, without the tracking of the vee.
And most importantly, no board will be at its best in waist high and double overhead waves.  Anybody who sells a board that "works for intermediate to advanced, in waist high to overhead waves" is marketing to a larger audience, and really couldn't care less about how the customer surfs.  Why do you think the pro's have twenty board quivers?
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I believe in feel - I know this is about as anti-technical as you can get but OTOH it makes the most sense to me. The problem I believe is know how to connect what you feel to what contours contribute to that feel, like the board you describe (Larry Mabile twinzer) that flat out flies which could be based on any number of factors not the least of which being where you stand and how you distribute your weight dynamically. Could be poo for the next guy. FEEL. I would want to know everything I could get from an hour with calipers and rulers and straight edges. I think what you feel is important because especially with subtelties in board design you will sometimes get 2 highly respected and experienced shapers who have polar opposite opinions about what does what. What matters is what feels right to you. From my experience, concave and V are not like opposites in the way that you have wide vs narrow or whatever - I have boards with both - this one is a bat out of hell:

7’3"  3" — 10 7/8" 18 3/8" 11 3/4" — 5 1/2" nose rocker 2 7/8" tail rocker — 1/8" single concave -> 3/16" double concave w/ 1/8" v

re: Nicaragua - I rode this board at 15’ (faces) Panga drops DOH Colorados and Manzanillo and it worked great (I am 6’1" 190 libs) lots of front foot drive which I like and goes hard on rail for power carving (tail = narrow / lots of rocker). I am sure the v doesn’t hurt the going on rail aspect but I believe its much more about the rocker and width. The concave probebly doesn’t hurt the front foot drive but I believe that is much more about the nose rocker.

As far as your question goes here is my $0.02. It seems that most of what I read says that V is a good choice for larger surf, and that concave is generally not a good choice for choppy / bumpy. I would guess that the recommendation you will receive from people who really know is that the FEEL you describe wanting should be a v bottom (or flat) - not concave = positive feel in larger surf. Nicaragua is an interesting component to the equation re: handling size. I have been several times and have never experienced really large surf - a 7’3" has been plenty, and never have I thought the bottom contours were really an issue, even DOH+ never had me feeling I needed a ‘special’ board. I completely agree with the comment re: subtleties vs correct rocker. For me, V eases rail to rail in a SMALL way that is unnecessary with the right rocker and tail width, and not enough to make a difference with the wrong rocker / tail width. OTOH, concaves add a little cushioned feeling to the right board and that feeling is trivial with the wrong rocker / tail width.

This is only my opinion as an illustration of the ‘feel’ concept. Keeping it simple seems to rarely be a mistake.

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Thanks…I was thinking of sticking to flat or maybe a very subtle V. 1/8" @ rail from stringer.  It’s hard to stay away from the “bells and whistles” but I suppose a more refined approach may have more merit than throwing the kitchen sink at the bottom.   Cheers

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I agree completely.  I don’t think you should pull out a pitching wedge when you need a driver.  However…Airlines only allow two boards a bag nowdays.  I will be bringing a 6’3" concave to double to V shortboard. 

And a replica of the board in the pic which I made for my buddy.  Obviously it won’t go great in waist high waves…but it went well in shoulder high semi quick and shifty beachbreak in Hatteras NC last week.  I felt like it would handle much bigger surf.  (Just interested in making the barrels with this one.)  I was asking because I think I’m going to switch it up a little and go flat or very subtle Vee with it. 

I liked your breakdown BTW.  Very informative. 

Thanks and cheers.

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I agree with the FEEL idea.  For instance.  I like moving around on the board.  a quick step forward or back dosn’t bother me. Even in semi large conditions.  It adds something to the experience for me.  Some guys want to plant and go.  And while I shortboard often. I really, and more often than not like a bigger board.  I can push a bigger heavier board harder than most of my friends can on their shortboards.  I like the weight of it.  I like hooking the tail hard in the face and watching the nose swing around like an airplane wing and feeling the weight of it as it rolls back into the pocket.  Even in 10 to 12 foot surf.   But this trip to Nica will be with smaller lighter boards. (at least for me) I want to log some barrel time. Since moving to the East coast from SD Cali a year ago it has been a strange change.  I have had to adjust to beach break, smaller, more traditional shaped boards seem to go better here. The waves are shorter, rides, faster, shiftier, and barrel harder.   In a way it’s bad, and it a way it’s good. (the frequency of good waves is bad…but when they do come, it can be really good. )

So with Nica having the rep. for lot’s of barrels.  I think the call will be something that I can sort of roll in from a touch outside and get into the slot and let it run.  I’d prefer not to airdrop into the pocket each time. I thought the 6’8" wide point forward, nutral to forward stance board with a pulled in tail would help.

I do appreciate your thoughts shreddoggie and will keep those dims in mind.  Though I may adjust them a bit down as the board is a 6’8" Mild Vee.  Just enough to break up the surface tension and initiate the rail to rail. 

Thanks again

Avi

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My mistake…the board is a 6’9" x 20.5" x 2.625"  EPS  6/4 deck 4/4 bottom.  Should actually be fairly equiv. in volume and boyacy to your 7’3" maybe even a touch more.  

 

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“Since moving to the East coast from SD Cali a year ago it has been a strange change.”

 

Have you experienced an infamous east coast hurricane yet? Where are you usually surfing? And watch out, the east coast will suck you in and keep you. Forever.

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ES and Dwight have it for me. Rocker, and in this context how your bottom contours affect it, are key. Roughing in (very simple) concave/vee before dialing rocker took my boards up a level.

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Well…I now live in Va Beach. Which has it’s moments but is generally not great.  But…I travel more now for waves that I live on the east coast.  Hatteras NC is not too far away and it’s a real hidden gem for waves.  People on the east coast know about it. But if you live on the west coast most people wouldn’t think of it.  It get’s good.  Really Good.  And fairly often.  Almost as much as Cali.  No real point breaks…but thumping beach break barrels.  The barrels are much more frequent, bigger, and more square.   But it has it’s tough moments too.  The frequency period is shorter and you need to be able to pop up and angle off quick.  No more Sunset cliffs roll ins.  No more OB Jetty bounce.  Just load up and throw yourself in. The waves can also be shifty.  Like a quick day at scripps.  Rolling, twisting and sectioning in several places throughout the wave.  It forces you to take advantage of what the wave has to offer rather than lining up the wall and carving up the face as you desire.  It’s different…but equally as fun.  The challenge comes from needing to react differently to each wave and hunt for the pockets of power.

Maryland was a surprising discovery.  That place spits hard.  No one ever thinks of Maryland…but that bastard broke my collar bone a few monthes ago.  7ft thick square barrels that hurt me bad.  Slamming down on less than a foot of water to a packed sandbar.   Place makes me nervous…Bottom sucking out of dirty brown pits.  But if your willing to take the hits it can offer up some of the sickest barrels I’ve ever seen. 

Another discovery of the East Coast was Puerto Rico…That place is amazing!  I’ve been to Indo, Deep Mex, Costa, Hawaii, etc.  And I put Puerto Rico up there as one of the most fun and challenging surf trips I’ve taken.  It was awesome. 

Another thing about the east coast.  I travel for waves.  In Cali I rarely traveled for waves.  It was better and I loved having decent waves in my back yard.  But East Coast forces me to get out there and look for it.  And believe it or not.  It’s good.  I experience new places.  I track harder. 

Also the lineups are easier.  A crowded day at Blacks is never the case.  And people are friendlier in the water. 

And the guys who are good are Soooo good.  They rip out here.  The need to be quicker on your feet, froth harder and go the extra mile to get waves makes them agro.  They aren’t scared.  Cold, nasty, hard paddles in washy conditions, they get in there and push it.   Don’t get me wrong…Cali is better.  But the good surfers out here want it just as bad.  And from what I’ve seen…Many of them would make Cali guys wonder who the heck just boosted that sick air right in front of them. 

I miss Cali…but East Coast dosn’t exactly suck.  (Except in the Summer…but Hurricane season is coming and I personally can’t wait.)

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Had to think about this one for a second as I normally do the majority of my rocker first and then push for concaves.  But it makes sense. Maybe a little more work as one brings down the thickness of the board to maintain the curves…but As they were saying…Rocker is the key…so if the “roughed” in concaves come first…then all you have to do is maintain them as you concentrate on the proper rocker rather than altering the stringer rocker while building the concaves.  Smart. 

I recently made a blunder of that nature on a good looking board.  Too bad it only looked good.  Darn thing sticks to water due to surface tention like glue.  I’m going to have to grind the bottom out and alter the rail line after a strong epoxy glass job.  Plus I will be ruining the the paint job.  But…I’ve come to terms with it.  Most of my boards work really well. But even after close to 40 boards…I’m still learning.   The pic is the board in question.  6’9" colored  mini longboard.  Such a sad waste.  Live, learn, and get more resin.

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[img_assist|nid=1075719|title=colored mini longboard|desc=|link=none|align=left|width=588|height=443]

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At least you have identfied the Problem. How I wuld say to to the rocker the board isn’t so much stuck in the water as it is pushing water. i do like the release you put in the rocker behind the fin.  

 Another way to get a flater rocker is to do like McTavish and keep the rocker line and slot the center not concave the center. the front and rear of the slot shold blend into the ocker edges left and righ should run perpendicular to The stinger say about 3" or 3.5" either side of the stringer. McTavish does  a V in the slot but I think flat would be fine. Steve Forestall also does this  Also think about rolling the forward rails again this will help with a wider nose board to not get hung up on the drop.  

 My Favorite Bottom profile in an Egg style Board is an egg low profile rocker with a touch more in the nose. A Hull nose with rolled upward rails into a 60/40? soft rail into hard rail in the tail  with a slot into a flat into a double concave out the back.  Just some thoughts. If you wat to look at some very clean Eggs check out Tony Staples web site do a search. He has some very very clean looking boards 

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Hi.  I come in peace.  V likes size, juice and handles chop well.  Requires less rocker.

Am I too old and live too far out in the Pacific to dislike the term "Cali"?  Rappers can't help it , surfers can.

Keep Charging.  Aloha

17

Um, nobody from California calls it “Cali”

Unless you mean here, "Santiago de Cali (Spanish pronunciation: [sanˈtjaɣo ðe ˈkali]), normally referred to as simply Cali, is a city in western Colombia and the capital of the Valle del Cauca department. With a population of 2.5 million, Cali is the third largest city in the country.

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I could never understand why people say that concave flattens out rocker because I always used the rocker inside the concave (computer designing is different). This quote makes it all clear now. Of course you lose rocker if you cut the concave into it. Now I understand why people say concave flattens rocker. But that’s not why concaves are quicker to get to speed. Flat bottom, concave bottom, same rocker - concave still quicker initially.

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I haven’t read any of the thread, but… I think , your pretty Cool.

You got me thinking with your “Been throwing the kitchen sink at your boards” call…When I thought… :wink:

Wow, thats it!!!

The Concave

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