Reductive Analysis of a Thruster

General Discussion
1

Hello,

I would like your expert opinions. Please follow along…

I was down in mainland Mexico at a long left point break. The wave has it’s moments but for the most part it’s a cruiser. So after a week of surfing this place in many different forms the swell slows down and the point started to get redundant and predictable. Since, I was without a long board and the wave was pealing off for hundreds of yards I cooked up the idea to start taking off the fins, one by one, on my 6’6 high performance Trifin to see how the thing ticked. The side fins weren’t very fun, but the middle fin proved more interesting. The result was I could take off go down the line and do a 180 and ride the board backwards for a while and swing it back around or do a 360 and keep going or slide the board down to the bottom and make the fins catch and start down the line. This was on demand. When I do these things with the middle fin in the boards it is usually much less controllable and once the fins reconnect with the wave it’s back to thruster business as usually. The downside to talking the middle fin out is that the board did not turn up the face very well at all, and this would be much more important in critical surf.

I have a Lis stlye retro fish and I have ridden almost every standard thing under the sun except MR style twin fins and quads. The lis fish does not behave this way with it’s two keels. My question is can a board be designed to let loose of the wave face on demand and be ridden forward or reverse? Like a modern skateboard or a wakeboard but for stand up surfing…

It doesn’t have to ride in reverse as well as it goes forward. And, when going forward it would be nice to get some of the drive back that was lost by removing the middle fin. What does this board look like?

I think it would be fun to have a board like this to play around in less critical surf. Before all the trim and glide purists tear me apart and tell me to go get a boogie board remember that a lot of thrill you had learning to surf was the rush that came from not knowing if you were going to make the drop or not. Sliding around on the wave face brought back a lot of that fun!

What do you guys think? What have you seen? Has this already been done?

Josh

2

My experience at this is limited, but I learned a lot at the same time.

I rode mainly modern shortboard singles, but put some small side fins on one particular board. While experimenting with the usual singles I broke one, leaving just the side fins, so I decided to stay out and see what happened. The waves were maybe 2-4 foot reasonably long quality beachbreaks.

With care I could sort of set the rail and ride along the wave, but as soon as I went to turn hard it would spin. So I kept my balance, and on several waves tried to keep surfing, backwards, forwards, even sidewards.

Riding the standard pointy nose backwards was interesting, as I could set the nose in the face using the nose rocker to help hold it in, but of course it spun out if I tried to turn with any sort of force. Backwards it seemd to like steeper little faces, I guess it was the curves.

It did get my mind thinking of a double ender type board, with small enough fins at each end to allow it to work going in either direction, like you said, not unlike a current twin tip kiteboard.

I didn’t pursue it any further, but on that particular day I had so much fun doing spinner 360’s and sliding closeout re-entries, I don’t know why I didn’t experiment further.

As I see it, in the not too distant future, top pro surfers will have to be proficient going both ways, switchfoot I guess you could say, so why not effectively on the same board designed for the job.

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I didn’t pursue it any further, but on that particular day I had so much fun doing spinner 360’s and sliding closeout re-entries, I don’t know why I didn’t experiment further.

Me too! Until the other day, I took the fin out of a swallow tail thruster and it rode much better than the squash tail I rode in mexico. That was going forward. They rode about the same in reverse. That’s what got me thinking about ordering a MR style twin and expermenting with small fins for breaking the fins free? But, that still doesn’t solve the going fakie problem.

You guys all know it’s fun to slide around. Remember Herbie Fletcher in the wave worrios videos… Long boards have the advantage of leverage on their side. It’s easy on my long board with enough rocker, and smaller fins, it’s easy to run up on the nose and pull the fins out of the wave face.

I ride skateboards a lot and would love to do all the slides and ollie on a wave. Kinda like the wake skate guys. But, the board has to paddle too. I have see attempts over the years. Like fins that retrack when the board is going the opposite directions. And, the 50/50waveskate guys seem like they are clued in. www.fiftyfiftywaveskates.com. But, they seem to want to get above the lip. This is were losing the drive from the removed middle fin left me with a bad taste in my mouth. By removing the middle fin the board went down the line much faster, but it didn’t harness the speed in a direction change that would ultimately get you above the lip. Getting your fins out of the water above the lip, in my experience, is an other way to get the board to slide. Or, torque out the fins until they break free. ie Kelly Slater.

What where/are shapers doing on modern short boards to enhance tail slides? More rocker?

By the way, wake skates have interesting rails for spinning and other bottom contours for doing what they do. Is anyone out there building wake skates?

so I decided to stay out and see what happened.

This is how it starts!

Josh

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hey Josh, Check out Dan Malloy in the movie “Sprout”. There’s a section in Sri Lanka where he rides a

standard thruster with no fins at all. He makes it look easy to slip and slide down the line.

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from what you describe are what my friend says how a modern twinfin / modern fish rides. . . I’ve never ridden twin fins, but this is going to make me remove the center fin on a weak day . …

6

You’ve pretty much described what kiteboarding in waves is all about, not to mention the jumps and spins while shooting out the backside…

Here’s my typical wave twin-tip…

A.P.


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hey Josh, Check out Dan Malloy in the movie “Sprout”. There’s a section in Sri Lanka where he rides a

standard thruster with no fins at all. He makes it look easy to slip and slide down the line.

I have the movie! Dan Malloy must have been thinking the same thing. Paddle out with your fcs key and take the fins off one at a time and see what happens. I put them in the side pocket of my shorts or stuff’m down my wetsuit. It makes a crappy day a ton of fun or a less then challenging day a challenge.

When I was a kid I saw a guy in Hawaii paddling his board backwards. Being a grom at the time, I wanted to tell him that he had his board pointed the wrong way. Then I saw him take off and spin around. I thought that was way cool, so I did that one all the time when I got bored and/or the waves where poor.

The fact is we could all get booogie boards and spin around all day, but I want the drive that you get from a proper fin set up. Can you have both or are these opposing principles that cannot coexist. Surf design has spent a century perfecting the user’s control of a surfboard. Now, how do we turn it on and off?

The glide purest will claim that this is an unworthy pursuit. My opinion is that the novelty of side slipping and spinning wears off. So, if the board can’t carve and slide on demand then it’s one dimensional and will only be a novelty. But, spinning around and riding the board in reverse and carving and still being able to get up the face or above the lip is gotta be fun.

What does this board look like?

Josh

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Quote:

You’ve pretty much described what kiteboarding in waves is all about, not to mention the jumps and spins while shooting out the backside…

Here’s my typical wave twin-tip…

A.P.

Ok, That is a start.

Kiteboard design must have some clues. But, you don’t have to paddle on a kiteboard and you have a unique source of energy to draw from when your plaining on a wave. Do you ever catch those front fins on accident? Do you use leverage from the kite and the sharp back edge to turn? I have never kiteboarded before…

Thanks for the pictures,

Josh

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Kite leverage, yeah I’d say that’s an apt description. When I throw my body weight down a wave face hard, I usually dive the kite down hard to the waters edge as I’m railing over to toeside (as in a hard classic bottom turn). You can throw the kite over your lead shoulder with similar effect but this tends to unweigh the board and the turn is usually more slidey/ snappier… With practice you turn rail to rail much like surfing, but with an added power source that provides lift so you don’t stall or sink through turns… At first when you’re just learning you do catch the front fins a little, usually being due to underpowered riding conditions and not knowing the sweet spot as far as front to back foot pressure, but after a while you rarely catch a front fin during any sailing or transitions, after all the fins are usually less than 2" tall.

Those of you here that surf powerfull waves are very lucky indeed !.. For those of us who don’t see really big waves that often the added kite power boosts the rush!!

A.P.

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I think you would either have to do one of two things with the rocker to make a board that goes both ways. One is using a three stage rocker, the other is a constant curve. The front fins would need to detach as the board planes and you ride off the back foot. Therefore, the fins can’t be too deep. You might compensate by making fins with more base area. If you want a board that rides like a thruster I would make the rails hard all the way through. There is a board manufacturer called Spun which makes double end surfboards, never rode one, jsut saw it on the web. With a little bit of innovation and a good idea you can make what ever the f*ck you want, don’t get hug up on what the pros are doing, jsut have fun. I suck at skateboarding, but I do snowboard and wake board a bit would love to be able to go both waves on a wave…but I wouldn’t sacrifice alot of the things thrusters are good for like control and being able to dig a rail and turn on a dime.

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Hey I googled Spun surfboards and found this video:

http://www.abc.net.au/newinventors/txt/s1076397.htm

realplayer movie in the middle of the page.

Their website: http://www.spunsports.com

They have some video on there site too!

My reaction was that I get the same results taking my middle fin out of my standard thruster. The boards they showed seemed to lack the drive of a proper surfboard. Their boards are “double ended” as they call them. The fins seemed two small. So they can spin around really well, but the can’t drive down and clear sections or all that other really important stuff.

Maybe a board that is not equally designed at both ends would be more fun. So, going forward still has the drive of your short board. But, you still have some control going backwards. It is rare at the skatepark to see someone that can really pump around the bowls fluid going fakie.

I like the three stage rocker idea that was suggested. I imagine that the middle of the board should be flat and void of contours. Does anybody have any ideas for the tail? or fins?

JOsh

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Placebo, …lost’s Vietnamese bastard step-child brand has a double ender SurfSkate:

http://www.placebo1.com/products.html

Scroll down a little to see their marketing blurb on it.

I think these just have standard thruster set-ups. Seems like a quad setup would be good for what you’re talking about. Tons of drive but still loose and easy to break the fins out. It would probalby be good too to go really small (under 5’) and wide to keep that wakeboard/skateboard feel too it so you didn’t have to move your feet around and could just kinda keep a centered stance like you do in snowboarding. Just flip it around and ride fakie then you could do a fakie re-entry off the lip and keep on trucking regular stance. Opens up a bunch of possibilities as far as what is possible.

I think this kind of board would be more popular with more of the crossover guys who are used to riding switch and not so much being stuck in a directional mindset.

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Here’s another intersting link I just pulled up while searching for Greg Loehr’s “Double Ender”.

http://www.surfermag.com/magazine/designforum/dfarticles/magiccarpets/

And a pic from the Placebo site:

edit: and another:

14

I just dug up this thread and it’s something I’ve been fascinated with for a while and I’ve been drawing templates and cross sections for a while. BECAUSE, it’s not airs I’m fascinated with , but being able to turn (carve) rail-turns from the center fore and aft, on a shorter board–a skateboard for the water–swap ends at will. I can do lots of fun stuff like that on a skateboard, and it’s standard operating procedure on wakeboards, snowboards, kiteboards, wakeskates, etc.

So there’s no reason why it shouldn’t work. And now, come to find out, it does work. Look at the Spun website. One thing that surprises me is that they didn’t modify the FCS fins to be more like wakeboard fins–low aspect, long bases, no hooks. Surfers get tunnel vision?

I’m also wondering if there aren’t ways to use concaves more effectively and still make the rails forgiving–and I’ve been wondering if Walden’s Magic bottoms might not be related to the concaves on kiteboard and wakeboards. The fins on wakeboards today may point a way forward–interesting to note more of the wakers tech hasn’t bled over to the fin templates too…

But why has Spun now apparently gone away? Could it be because the powers (and pros) that be don’t want bi-directional surfing to become a norm??? Nah, that couldn’t be it… Could it (also) be that surfers, especially older ones (some more so than others certainly) don’t want surfing’s state of the art to pass them by completely?? Nah…

Interesting to note the naysayers include Al Merrick on the Surfer piece referred to above… Whereas Greg Loehr apparently made some of the things, …lost is in the hunt now (although Biolos says no surfer would try anything switch on a wave of any consequence–how well does he know that?? Has he ever heard of Danny Way or any of a thousand nameless skateboarders who are jumping down staircases and off buildings going backwards landing on CONCRETE ??)

Anyway, I’m up for info-sharing (templates and stuff), I visualize double enders with concave decks and kicktails, magic bottom centers to deep sharp rails at each end to flat kick, hull-like mid-point turning capability + back-on-the-tail ripping up the face into aerial stuff…

AND, dig this, how about a non-symmetric double-ender, one with a assymetric wide point, for WP forward fish-styley carving, (maybe a cheater five here and there?) and switches out to back-foot heavy aerials capability on the same wave…

But to start, a wakeboard type surfboard, with wakeboard type fins or slightly modified Lokbox Bonzer sides in no-toe trim set back from their normal config, with a removable wakeboard type center fin at each end…

That’s all for now. Who else is in? LeeD said that I was a dreamer when I broached this very subject last year and said it was the way forward…I think I’m not the only one… but for me, it’s mainly about the cess-slide and nose-slides, fakie-riding

Man all those FCS fins are terrible for that application–haven’t these guys ever seen wakeboards before?

( http://www.boardstop.com/ ) Lots of interesting things to tlook at and think about here

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Hey Janklow,

Yeah, I agree with Biolos though no surfer would try anything backside on any wave with consequence. For instance, a backside 540 rodeo in a contest would never be attempted.

So oh well, I guess what we’re seeing being done now is the pinnacle of surfing and there’s no more room for progression.

Cheers,

Rio

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a bit like this?

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Quote:
So there's no reason why it shouldn't work. And now, come to find out, it does work. Look at the Spun website. One thing that surprises me is that they didn't modify the FCS fins to be more like wakeboard fins--low aspect, long bases, no hooks. Surfers get tunnel vision?

I’m also wondering if there aren’t ways to use concaves more effectively and still make the rails forgiving–and I’ve been wondering if Walden’s Magic bottoms might not be related to the concaves on kiteboard and wakeboards. The fins on wakeboards today may point a way forward–interesting to note more of the wakers tech hasn’t bled over to the fin templates too…

I just started wakeboarding. The fin systems on wakeboards don’t allow you to turn nearly as well as surfing fin systems - you yield control for the skati-ness.

Not to mention wakeboarding started out with surfboard tech, and evolved to where it is today. Make a board faster by giving it wimpier fins, and lose turning power.

On waves of consequence, you want every bit of directional control you can get.

Also, no wakeboard-style fins in the barrel, except by luck. They will run away from barrels - not be able to hold a high enough line.

On wakeboards and kiteboards you typically have a lot more power pulling you, and a lot less power chasing you.

I can see the allure of a skatier surfboard. I just don’t think it will resemble a wakeboard that much.

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Dave, that outline’s highly interesting–it makes me wonder what fins you’re running, what the bottom contours look like, and the rails …

I was thinking forgiving rails and bottom at the WP, with aggressive concaves near the fins, almost flanged, (short of Doc’s USO, but there’s something there)

and long base, low-profile fins, a hybrid fin, like Bonzer 3 siderunners, in a double-ended quad (maybe +1) configuration, maybe the quad config stretched out, to get the rear fin back nearer the tail, for things like tube-riding, set in a closer together quad config for skatier smaller waves to let the two fin apexes (which could be more squared off) provide a wider net purchase point, drive, and pivot, and release.

(An interesting application problem, you bring up, Blakestah, one that needs positive inputs. If fins had more aggressive leading edges, and (back) rails had more applied concave, or were flanged, cupped, some of the wakeboard manufacturers call it, rail side fins could be much lower profile and still do the job, I think. I’ve seen pics of one of the pro talents riding a big barrel with his fins out of his normal shortboard. I think concaves and channels just haven’t haven’t been carried to the leverage and bite and drive they could provide because fins have always been so big. And i don’t think the rails need to be carried to Doc’s USO extreme)

the leading quad fin even with the tail kick, running backwards, beveling the (designed-as) trailing edge to where it would work as a leading edge, i.e. a more triangular fin outline. I was thinking no toe-in, or very little, and no cant or very little. But I’m not married to anything.

One thing I think anyone can see is that if surfboard manufacturers had taken on foam manufacture at some point, they could have RnD’d much more aggresively. Surfboard blanks’s cost have been limiting for researching (edit: radically different, paradigm-changing) other ways and means. Then once a guy like Merrick gets big enough, he doesn’t care about doing things any new way, if he ever did… I mean, that’s crazy isn’t it, that Al Merrick never got into this angle? edit: Should a guy that uncurious even be president, I mean, own a large surfboard company?

19
Quote:

One thing I think anyone can see is that if surfboard manufacturers had taken on foam manufacture at some point, they could have RnD’d much more aggresively. Surfboard blanks’s cost have been limiting for researching (edit: radically different, paradigm-changing) other ways and means. Then once a guy like Merrick gets big enough, he doesn’t care about doing things any new way, if he ever did… I mean, that’s crazy isn’t it, that Al Merrick never got into this angle?

Its the economics of scale. Roughly 500,000 surfboards sold worldwide each year today, a few tens of thousands are CI boards. It costs hundreds of thousands if not a million plus to get started blowing PU foam. With CI’s sales numbers, it just doesn’t make economic sense - you could never overcome your initial investment. Now, if they work up to 40% of the market, it would make sense.

Dirt cheap to start blowing EPS foam, though…