MTB - That board looks absolutely brilliant! Is that a carbon section in front of knee pad area? And yes, please tell what the tail is made of - standard resin and glass? Doubt it.
i was real impressed with lee v 's comments on staged rocker, i had always thought of my rockers as clean curves , but after i read lee’s comments they are just that ,staged blending with curves,i also fully agree about the stage rocker being very outline dependant…
j troy …
i can give a basic run down on those curves, the top one is my performance longboard rocker, most of my team longboarders use that rocker , or something very close to it , it needs a bit more movement in the surfing , almost like a shortboarder on a mal, it works the pocket well , combined with the right outline noserides high and back in the pocket, doesnt like a heavy rider with a stationary style, doesnt like slow soft rolling waves , unless you have the ability to speed trim…i could go on …
the next 2 are very closely related to the bottom 2 , the bottom 2 have more rocker through the middle and flatten in the tail , more back foot drive oriented, ive used that style of curve for a long time , but i found it wasnt for everyone , especially with more tail rockered boards hitting the market in the last 10 years , more and more surfers developed styles which depended on being forward for speed and tended to not linger as long on the back foot , so 2 and 3 from the top have the flat reduced in the tail and not so much curve under the front foot , but still about the same rocker measurement , with the curves in a different place, you can stand more in the middle and keep speed without as much movement,the bottom 2 need an aggressive surfer with a tendancy to feed the back foot right out the end of a turn…
the middle one is hell flat ,its the cowboys rocker…the one that takes you for a ride with no effort required from the rider, paddles well ,you just stand and shoot,has good speed by itself…
put an agile energetic surfer on it and they hate it…its fast for an average surfer , slow off the mark for a good surfer…
the next one 3rd from the bottom is a flat giant version of the bottom 2 ,its got 1 1/2 tail and 4 1/4 nose in a 7’-6" for small flat waves for someone who likes to work the board ,still use the back foot , but is flat enough overall to just be able to stand and trim if needed…
thats a fairly summerised version of those curves…
regards
BERT
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LeeV asked: Whoa!!! I wouldn’t want to go over the falls with that tail whirling around like a rotary lawnmower. Are you using the tail cut out to keep the stinger rocker stiffer? Or does it serve some other purpose? Glad to see the Skunk Works are still up and running…
Are you flexing the mid section (the red area) too. It looks spooned.
Not a pleasant thought, is it? …and I try to avoid it. However I’m afraid that I’ve gone over the falls many times with this board and its predecessors. But I’ve ridden this type of kneeboard from 1969 to the present and not had a problem with an injury associated with the tail section (yet). So I think the odds of such an injury are low and probably are comparable to that of more conventional boards. I also think I’d rather get hit by the tail on this board than than getting struck or stabbed by a fin (or two fins, or three fins, or four fins) as the leading and trailing edges of the latter are a LOT sharper than the edge of the glass tail on these boards.
The cut-out is simply to facilitated kicking with swim fins. The stringer rocker is stiff, but primarly due to the increased glass thickness. But yes, the shorter distance between the foam and the end of the glass also contributes to that stiffness.
The midsection (red area) is spooned (glass only) and will flex (although not intentionally a design element). But it’s actually pretty rigid because of the compound convex curvature due to the nose rocker and side-to-side belly.
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J.Troy asked:
Thats interesting…how thick is that tail section and what is it made out of to get that flex?
That tail section does look dangerous of you got clipped by it…
So how does it ride?
The tail section is laid-up with conventional materials: Std polyester laminating resin (unlabeled as to source and properties, from Mitch’s Surf Shop–probably 1.5% enlongation); the top and bottom glass layers are 6-oz, bi-directional Silane e-glass; the intermediate layers are 8-oz 90/10 uni-directional Volan e-glass.
The thickness changes according to the number of layers of cloth. The greatest number of layers (3 6-oz, 8 8-oz) is along the stringer line bridging the transition between the end of the foam section and the all glass tail section (the area of highest stress in the entire board), with each internal layer tapering successively in in width aft in the form of a narrow arrowhead (pointing aft). Near the two rear tips, the total number of layers is down to 5 (as best I recall). However, there are two additional narrow layers in the immediate vicinity of the tips to increase their resistance to damage, and to minimize the damage should one have the unfortunate luck to get stabbed by either of them. The fiber orientation of the intermediate layers is approximately parallel to the outer sides of the arrowhead (changing the reference side of the arrowhead with alternating layers).
Just forward of this tip reinforcement, the thickness of the tail at its side edge is about 0.125"; at the back, at the location of the ‘stringer’ (or where it would be), it is about 0.190".
As to how it rides…what can I say? – I’m biased! When I started kneeboarding I experimented with both this type of board and a few conventional construction kneeboards. I liked these best for a number of reasons, even though they have some obvious deficiencies in some regards (e.g. paddling speed and competing for waves). Other riders’ opinions may differ (and probably do, based on the nearly total lack of copies).
Once I had the basic configuration and flex to my satisfaction, I rode the same board (“Cetor”) almost exclusively (in a variety of conditions) for 26 years before deciding that it deserved to be retired to a place of honor. Cetor was followed by a three board (more specialized) set: (1) this board (“Cypselurus II”) for small waves; (2) “Black November” general purpose and larger wave board); and (3) “Red October” (larger waves, particularly lined up walls). All three are variations on this same theme.
These three boards should meet my needs for years, so the ‘Skunk Works’ (thanks for the complimentary linkage LeeV!) is presently focused on the development of hydrofoil paipo (HYPO) boards.
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John Mellor commented:
MTB - That board looks absolutely brilliant! Is that a carbon section in front of knee pad area? And yes, please tell what the tail is made of - standard resin and glass? Doubt it.
Nope, everything is plain old e-glass and polyester resin.
Normally I would have made the tail section semi-transparent (as with the fwd red spoon section). But the tail section (off white area) was originally intended to be covered by a flexible closed cell foam and skin to provide additional buoyancy to help when paddling–and hence one layer of glass was pigmented so voids, etc. in the adhesive bond wouldn’t be visible). But this flexible foam was never added due to concerns about the integrity of the bond(s) between the foam and the glass, and achieving smooth joints between the forward edge of the deck of the foam and the deck of the raised glass/foam structure.
MT
The future of design is probably in the secrets of controlled flex…
Fortunately, the new Swaylocks allows us to store images right here. Thanks to Dale for digging these up. I thought they were on topic…
