Aloha . I had thought that concave ,like double concave was faster than a flat bottom now I’m not so sure from some things I’ve seen… Whats the deal? Thanks…
from what ive ridden single concaves are faster than regular flat bottoms, maybe someone can tell u why and how. dj
It’s all relative to the type of wave and the persons weight, ability etc. You can’t generalize there are too many variables. Personally I go flat bottom on mushier surf, 30 years in florida has proven itself to me. But I have alot of friends that disagree, except when I’m steaming down the line. In everyday life it’s preference , in competition it needs to be addressed. I worry more about the right size board with the right fins for the right condition.You can’t go wrong… http://www.soulsurfertv.com
Flat bottom concaves have useability…! In fact upon looking at Pauls Coles design more closely I noticed the concave is giving Pauls design an ultra flat rocker through the main section of the board but still utilising curved rocker in rails to allow turns and gives the board a syncromesh fit into the wave, the best of both worlds. Flat bottom for speed with rockers on the rails for turning. Thats what I see anyway. And for tight radius turns there is a third rocker that starts from the leading edges of the wings and runs through to the tail. So get the pic of the side elevation of FP and draw a line from the nose to tail this is the long arc turn… then one from wing leading edge to tail this is short arc turn… and finnaly draw a line from the beginning of the concave to the tip of the concave this is the flat rocker for speed. Keep looking guys theres more in it than that… http://www.geocities.com/wunderboyi/ninetysixpercent.html
Florida… Fast down the line??? Somebody’s gotta hold of their bits!!!
any contour in the bottom of a board ultimatly will divert or change the direction of water in some way …change the flow of water and you use energy…the cost of that energy is loss of speed …if you have energy to burn you can put in a concave for a particular feel …but if you dont have energy to waste and your surfing soft waves ,flat bottoms are way faster and its provable mathmatically and to argue the point would just make you look stupid in front of those who understand why… regards BERT
Flat is fastest. Concave adds elements of control. Bert is right.
Hmm… Fl never fast, never down the line. I guess we should all just pack it up and move to Mucka-ville, where the waves and wisdom abound… http://www.soulsurfertv.com
It isn’t a matter of bottom shape… It’s a matter of balance with all the design elements. Speed is relative.
yep thats true …reletive to location and power ,speed and the many variables involved…but taken as 1 peice of the puzzle flat is still the fastest…but sometimes speed is not the goal ,its control…how much speed do you want to lose in order to gain some measure of control…can control be gained in other ways without sacrificing speed??? regards BERT
Flat bottom concaves are stable lifting shapes if executed correctly. If you look at the shape of the bottom on FP it does look complex but when you put a flow over the bottom there are some surprises…the flow is straight yes straight work it out for yourselves…build a FP put it upside down and fasten to stands and grab a firehose start with small amount of pressure then increase you will see it for your self. http://www.geocities.com/wunderboyi/ninetysixpercent.html
Other shape parameters “equalized”, my experience has been that a flat bottomed single fin will both out-accelerate, and be somewhat faster down the line than concaved bottoms.
Bert- Great posts. Much appreciated. I agree. I’ve always felt concaves to be a little sticky and not worth any touted extra speed, which I couldn’t feel anyways. I’ve always suspected my flat bottomed, slight vee boards to be the fastest and quickest reacting boards, hands down. Whenever I’ve given in to the concave hype, I’ve returned to the flat/slight vee bottoms with smiles.
Ive built rolled, flat and various concave bottom boards. Ive also built flat bottomed designs, surfed them for a while and then added different types of concaves. In every case, they were dramatically faster. Finned and finless. Their low end speed was markedly improved, but they also became harder to handle in larger, more powerful, rougher conditions. I discovered that flexible shapes were able to work much better with greater degrees of concave than with rigid ones. A narrower board with the right blend of concave can be made to feel/function as though its wider. For a shape with concave to function well over a wide range of waves and conditions, it needs to incorporate other contours (often convex) to balance the overall handling. Its all about balance.
My experience has been that concaves are quicker off the first turn or two and are easier to turn as well.They get crazy out of control in big waves.
Crazy out of controll concaves need stabilisers and canards to stop yaw…Guys I agree its all about balance hence 40 prototypes… FP ConCaves start about 4" before the wings begin they are not shaped rail to rail as this makes CCs catch an edge…Pauls leaves a neutral section which overcomes this…The purpose of the FPCC is, at high speed it provides lift it also provides a straight rocker through the mid section of the board…The plan shape of the concave is similar to a big wave speed board as is the nose…But if you joined these two together it would take alot of speed to make it work… Bring in another subproduct, “low speed lift sections” which are the wings, and the wings have some multiple uses…One being the afore mentioned low speed lift, they create the rail line of a modern 19" wide board, they form a rear short radius rocker for tight turns, they at high speed are neutral and become stabilisers…I know wings are freaking out the mainsteam guys. Go back to the spoon experiment. A spoon in the flow of a tap will want to pull itself inwards…This is precisely what happens over the wings… So those out of controll CCs can be tamed !!! http://www.geocities.com/wunderboyi/ninetysixpercent.html
ok …my opinion is flat is faster …its provable … but why do so many say they notice the increase in speed when putting a concave in ??? because they are attributing the increase in speed to the concave and overlooking the real reason why its faster…reverse the process and then tell me if its still faster??? get a standard rockered flat bottom ,then cut in a single concave ,adding the concave will make it faster only because you have flatened the rocker line ,a flater rocker is faster ,now which of the following is faster? the above board or one that is flat with the same rocker as the new rocker line along the stringer of the concaved board …see? now work in reverse and tell me which one is faster a flat bottom or the same board not with concave cut into it ,but if was possible to add foam build up the rail line to make concave ,now you have a flater rocker and actually added rocker which of coarse will slow it down… so to cut it short the increase in speed is not due to concave ,but to rocker change… also the comment about flex stiffness and concave is absolutly right ,if you have flex in your board then tail concave actually becomes a flat bottom when you load the rail .thats why so many pros ride concave coz there boards are glassed so light… regards BERT
Bert you are a deep thinker…Im trying my best to keep it simple and you are not making it easy…If you want to know more about FP concaves ask a couple of questions to Paul Ill make sure hes gets them… http://www.geocities.com/wunderboyi/ninetysixpercent.html
It’s soooooo hard to think… us idiots can’t understand how concave adds a second rocker line… How could flex change bottom shape? HELP! I’M SO CONFUSED!!!
Methinks we must all tout our singular activities most highly for this will lend us to open conversation so well – T.E. I trust the FP will soon start it’s breeding season and we’ll be relieved from having it flounder through every thread here on the forum. As it’s so imperial, we find it balancing that egg on its feet at some polar ice cap, which may never hatch. No basket and just one egg ~ Man, that’s a tough life! With that said I’ll move on to the bottom configuration and speed discussion: Hmmm… is there really an answer? The idea in surfing is to get as much out of the wave as possible so a board that is performs best in the type of waves one is surfing and suits one’s style is what we search for. In steep hollow wave it’s not the same thing as in big open flat sections, so choice is a relative thing. One of the most fun ways to surf is to have a board that fits into the critical part of the wave and goes fast enough to get out of trouble and is at the same time a nimble turning device with plenty of drive. If you need straight line speed and want acceleration a board needs to ride up on top of the water. Boards like this don’t fit into the critical part of the wave as well as ones that surf with greater speed on flatter sections of the wave face and thus project much better. Finding a marriage of these elements is what bottom, rocker and rail configuration addresses. It would seem to this humble observer that less wetted surface means more speed. A concave pulls the center section of its facet up off the wetted surface. This causes ventilation and makes the facet more slippery in the center and bite harder at the edges and by not having as much water contact leaves this given facet with less directional stability than a flat surface of equal weight. Weight is a key factor here. On heavier boards like Volan glassed longboards and tow-in boards which are very heavy the ventilated section under the board acts as a cushion and allows the board to go faster while the board weight helps maximize directional stability. As boards become lighter the ventilated water under to board wants to squirt out, so when a little chop appears on the water the light weight concaved bottom board becomes skittery. Rocker and rail are part of the speed equation but since were discussing bottoms configuration I’ll leave rails out. As tail rocker decreases all boards become less turnable while downline speed is increased. On longboards the tail flip we see at the end of some boards does several things; it allow one to turn the board more easily and as weight is moved forward on the board either less of the tail and fin is in the water resulting is less resistance, more speed or the flip in the tail is under water and it tends to hold the tail in better and cause the board to stall ~ obviously concave on the tail of board like this would be of no use at all. My point is that the generalizations about concaves can be very misleading. Some longboards are now appearing with more modern tail sections and have vee’d double concaved tails which offer a lot more punch and speed in bottom turns then their predecessors. On short boards because one surfs off the tail exclusively so concaves are pretty much standard fair on a vee’d tail here. Lift and bite equals more control and speed and a board that requires constant adjustment of trim line to perform. There isn’t a lot of planning area on a 6’1" so it may be that a central concave is better that a flat one because it offers more lift that the flat one does but a waves become larger and the water surface rougher this type of bottom becomes a liability. One must consider that, as Bret says, when one puts concave in board bottom rocker is decreased so the same board with a flat bottom will have more rocker. As a result it’s hard to make a fair comparison because we must agree that less rocker equal more speed. The bottom of a surfboard is constantly reforming to conform the reforming process it lives in ~ odd but true. So in the end it hard to pin things down because there are so many things happening in the rocker, bottom, and rails of a surfboard. Different wave conditions dictate what will work the best and offer the most speed and performance. Choose your stick accordingly. Our appointment is with both speed and performance, which can’t be separated once you drop in ~ as to options ~ they’re infinitesimal. I’ve got some ideas I just have to try ~ off to the shaping room, Rich