Tried to draw a graph and failed oh well–vertical (Y) is speed horizontal (X) is control. Draw the line showing as speed increases control decreases and vis versa.
So add a given design element to a board say concave; increases speed and decreases control. So to compensate add some convex curve to bottom i.e. flat plane chines (tri-plane) or more roll under edge of rail. This will increase control but increase drag also or reduce effective planning area and so reduce speed. How is this an advantage? Or isn’t it? Do we end up at the same place as if we made a simpler bottom?
There is always the quest for more speed and control at same time but are we getting that by swapping around these bottom contours? I have never gotten to ride enough different yet similar boards in a small enough time frame to really forrm an educated opinion.
So to make a concrete example, will the same overall board one w/ concave bottom and tri-plane to balance handle signicantly differently than one with neither but otherwise same template, rocker, rails, fin etc?
Sheesh, I hope this makes enough sense to get some feedback…
I guess I’m after subjective feel i.e. at some wave size/power board maxes out and you need a different design to handle and perform similar moves (within reason) to what you were doing on the smaller waves like square off bottom and fast drop, get some degree of vert, ease of holding line on cutbacks, holding power on the face in steeps etc
have you ever shaped a double con or vee into a board’s bottom then rode it for a long while (one month one year), then peeled the bottom skin off shaped a deep single concave, reskin it and surf it again?
I have. Twice on two seperate boards.
No comparison between single cons and the other stuff you mentioned.
Speed v Control is very subjective cuz we are all surfing different places with different power/speed but generally speaking, I like cons in avg to good mainland conditions, flat ot flat to slight vee in island juice.
BTW, a flat with pinched rails has the same similar affects
“BTW, a flat with pinched rails has the same similar affects”
That’s the kind of thing I was after. Have had some private conversation w/ Dale Solomonson on bottom contours but not this specific question. Thought it interesting enough to go public. Hope Dale weighs in as I know he has done what you did in various forms a number of times like make board w/ concave, fill it w/ bondo or microballoons and between go outs remove and add back fill to the concave.
The part I’m interested in here is the interaction of two or more variables to get the same result with the idea of getting the result with the simpilest shape possible. Can you get to the same place in a simple way (in same surf conditions) or do you really gain something by making the much more complex bottoms?
Another try: For given handling characteristics in given surf conditions you can approximate identicle handling by two dif boards by 1)adding concave shapes to bottom to increase speed (thereby loosing some control) and then regain that control by adding some convex shapes (incidently loosing some speed) or 2) keep a much simpler bottom shape ie the one you had before adding concaves and convexes.
What do you gain by adding the complexity to the bottom vs keeping it simple? Are we chasing out tails into increasingly trick bottoms and not really gaining anything? This is all based on a core of refined foil and rocker appropriate to the given conditions.
At various times, someone has added single to double concave say, or channels and liked what it did but also lost something in trade-off; subsequently adding some other contour to balance the trade off . Are they really back where they started but with a lot more shaping to get there? Or, what is gained?
The idea that at higher surfing speeds a loss of control is inevitable is ridiculous. . . . !!
Waterskis and windsurfers maintain control at high speeds, and so can surfboards. . . . but lightweight wide tailed boards with toed in side fins DO have a problem. . . .
What do you gain by adding the complexity to the bottom vs keeping it simple?
I think you would ‘gain’ a less user friendly board…complex bottoms likely generate complex flow…complex flow might generate more unwanted turbulence…
…less is more.
but dont tell that to a bonzer afficionado
its a very complex issue but i think the easiest way to look at it is this: some bottom features add lift and reduce pressure; others bottom features add suck and increase pressure…this holds true for contour and rocker and rails…so depending on application you either choose lift, suck or middle/neutral…and there are countless variations of features…talk about complex!
Pin tails are single parameter, I’m after interaction of 2 opposites. Not enough sleep, but its later in the day and here’s hopefully a more clear question.
Everything is the same: rider, wave, all surfboard parameters except-- one board has basic flat bottom; the other has double concaves added for speed plus chine/triplane added to improve control/handling ease (there’s the one that speeds and lifts; and the one that drags and slows). Are these two approximately the same or is something gained by the more complex bottom or maybe lost by just increasing turbulent flow?
One answer to such questions lies in wave riding vehicles that can change their contours in direct response to the wave and rider.
Tuned flexiblity is an efficient means of bridging and balancing design compromises between speed and control over a wide range of waves and surface conditions. This is easily experienced on flexspoon kneeboards which bend to fit the wave face.
And beyond flexible (but solid) spoons, the final manifestation of an ultralight, flexible, malleable surfcraft with balanced speed and control is the modern surf mat… adapting its entire shape and buoyancy distribution to a wave’s curves and textures.
“… at some point the bottom of the mat just seems to disconnect from the water, and you just hurtle along, but with control…”
Everything is the same: rider, wave, all surfboard parameters except-- one board has basic flat bottom; the other has double concaves added for speed plus chine/triplane added to improve control/handling ease (there’s the one that speeds and lifts; and the one that drags and slows). Are these two approximately the same or is something gained by the more complex bottom or maybe lost by just increasing turbulent flow?
i see where youre going now. again its more complex than that but lets assume instead of the double con you use a single con instead (your situation would make a bottom with three shallow vees…not exactly oozing with speed). in a situation where there’s minimal control common/intuitive technique is to either rail the board or lean back on the tail, or both so its reasonable to assume that your rails and tail features offer control while the centerline offers less control. so theoretically your scenario could work without the double. too much tho and you end up with a bottom with two parabolic vees running full length (three vees with a double).
i had a funboard once with pinched rails and single con and i’d say it felt slower than faster…but i dont like fb anyway so…
one thing to note…the bottom feature near the rail has much more affect on speed v control than the centerline/middle…assuming your rail surfing…steep concave slope near the rail will facilitate release while a pinched rail (convex slope) will hold/suck…my shorties feature singles with steep slopes near the rails for max release and lift…the rest if the concave shape is very shallow parabolic…
but hey, ROCKER is still KING!
ironically its also the most ignored design feature…mainly cuz its harder to see and understand…
Meecrafty, youcrafty! That’s more what I was after combined w/ Dale’s comment. Fits the plan of flex tail–variable rocker adjusted by wave forces. Rocker Is King; could be good name for a band.
All actual Lis fish I have seen have very slight flat bevel at rails. About 2 1/2 to 3 inches wide and about 1/16 deep or slightly more.
