First-ride review on Blakestah's "Surfboard Trucks"

For those of you who live in a hole, blakestah is a very talented engineer whose out-of-the-box thinking has brought us the rotating singlefin system, and most recently, the rotating thruster system. I was seriously tempted to try the RFS single, but held back. When he came out with the tri setup, however, I had to pick up a set.

I generally don’t ride tris, as I don’t like the way they feel when you do anything but turn them. They turn great, but I always felt like the brakes were on as soon as I stopped going rail-to-rail. As described, Blakestahs system seemed to have the necessary qualities to fix that particular problem for me. Within a certain range (I think 1/4" toe in to 1/4" toe out, that right?) this fin system optimizes the fin toe in by allowing them to rotate. Toed in for turns, straight ahead for going straight.

Ok, enough background stuff, time for the review.

Boxes:

First, the boxes are very robustly built, and engineered very elegantly to do what they need to do (rotate the fins, duh)with the fewest number of moving parts. As far as I can tell, there really isn’t anything that can break internally to render it unusable. Tolerances are very tight, and it seems unlikely that it could get jammed with sand, unless you stuffed it with mud and let it dry out. The fin attachment itself looks to be pretty bulletproof, and could easily accomodate another fin of your own design, or one of rainbow’s stock shapes, as I’m sure they could put the proper tab on whatever shape you would want.

Installation:

I ran into a little trouble on installation, as there is a lip on the top of the box to act as a resin dam. I understood the instructions (and I very well may have misunderstood) to be to install the box before lamination. I could see the potential for bubbles to form under the lam at the square edge of the resin dam, so I beveled it before lamming, but I wound up with some bubbles there anyway. Had I been doing a clear lam, I probably would have seen them and chased them out, but I did an opaque white, so I didn’t see them until I sanded it all down. It wasn’t any big deal, and an easy fix, but that might be something to think about for future runs, beveling the lip somehow.

As I said, the tolerances on everything were quite tight, so much so that after I had everthing finished, the boxes sat a little lower than flush with the final lam, and the fins rubbed a little when rotating. A few strokes with the sandpaper got everthing fitting right, but better too much material there than not enough.

Setup:

The only real frustration of the whole pre-surf process was trying to get the little rubber bumpers back into the boxes when putting everthing back together for the final fitting. After a few teeth-grinding minutes I did figure out a method, but it was still a challenge to compress the rubber and insert it with the other thingy. The small bits that go between the rubber and the fin shot out at me a couple of times. Once it wound up a solid 25 feet down my driveway, and the other time it tried to damage my face. The good thing is I don’t anticipate having to take them in and out too often, so this shouldn’t be a frequent aggravation. Again, not a big deal, but when it’s the last thing before hitting the water, it seems like torture!

The board:

The stick I put the system in is very similar to my MR-style twinnie. I thought about using a more typical thruster template for this application, but in the end I decided it made more sense to use a template and rocker I am already familiar with and enjoy riding, to better make a direct comparison. The only changes I made was to make the tail a squash instead of swallow, and to soften the rail a little. Everything else is the same as my twinnie.

The conditions:

Not quite head-high on the outside, not quite offshore winds (sideshore, actually), but the swell was pretty solid for around here, the waves were actually peaking up, and it was a pretty damned good day for texas surfing. The forecast called for this one for the last week, so I had rushed this board to get it ready for today. I literally sprayed on the sealer coat an hour before it got wet.

The ride:

This is what it all comes down to, doesn’t it? In a word, it was FUN. The kind of fun that leaves you smiling all day long. As I said before, I’m not a thruster guy. This was far and away the best session I’ve ever had on a Trifin. Actually, one of my two best sessions of 2006.

It was easy to find the sweet spot on this board since I’ve been riding one so much like it, so I knew what was going on with the very first wave I caught. I caught it, quick pivot to go right, then just rocketed down the line. I honestly could not believe the sensation of acceleration, it threw me so much I almost forgot to turn. But turn I did, layed it back into a deep backside carve, then snapped back around and was flying down the line again, just like that. It was really neat, to tell the truth. And it wasn’t like you could say “ok, now the fin is toed in, now it is straight, toed out, etc…”. The fins just seemed to be doing whatever needed to be done at that particular moment. Nothing felt odd or forced, it rode very naturally. If I wanted to straight-line it down the face, it was off like a rocket; if I wanted to crank a turn, it was only limited by my abilities; if I wanted to chop-hop a mushy section, it was making drive where I needed it.

And speaking of sections, I took off on a couple of peaks, went right when I should have gone left, and still made it around the wash when I really expected it to eat me up.

The verdict:

From the couple-dozen or so good waves I got on it today, I’m calling it two thumbs WAY up on this fin system. I’m definitely looking forward to spending more time putting this board in more waves, see if I can use it to push my own ability. I would absolutely recommend it without reservation.

Thanks Dave!

right then

i want some !

blakestah can you pm me some details and price etc.

Shwuz,

VERY well written write-up!

However, you deserve alot of credit for a VERY good looking board!

Hows about some specs on the board - and not just measurements - construction, foam type, veneer, glassing sched…

You know the drill here on Sways…

Give it up Shwuz…

Very nice job.

Pete

…thanks heaps for that detailed review Jarrod.

can you take some closeup shots of the fins and boxes now please , so we can more clearly see what they look like ? [ along with shots showing how much the fins ‘rotate’ / move , please ?]

cheers !

 ben

yes , great to see you riding a nice looking , homemade thruster , for a change !! …[for those who don’t know , thrusters work WELL , by the way !!]

please do NOT show close up photos of the innards.

The finboxes are 1.3 inches by 2.25 inches and a little less than 3/4 inch deep, and they are roughly rectangular.

The fins rotate from parallel to the centerline to 3 degrees in either direction. People hear about rotating fins usually think they rotate too much or bleed through turns, but the end-stop is designed so that the inside rail fin can NEVER turn too much. Instead, the basic idea is that between turns the fins are assuming the identity of the invisible man. When you lay it on rail, the inside rail fin is there and ready at a standard toe-in and cant. When you come out of a turn, invisible fins again.

A standard toe-in is 3.2 degrees, the 3 degree mark plus the backlash inherent in the design make it very close to 3.2 degrees.

The fins have a VERY normal template. Normal rake, a little long on the base width (4 5/8) and a little deep (4 5/8 again, IIRC), but the tip and curvature on the rear side, etc, may as well be a G5. Foiling is also very standard. I use a little bigger fins than most because the drag is so low in between turns that a bigger fin has no drag penalty like it does in a standard thruster, and there is an obvious advantage.

hth

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please do NOT show close up photos of the innards.

Yeah, I already kind of figured as much. Gonna break Chipper’s heart, but I’m sure he’ll appreciate protecting your IP.

Invisible man, indeed! Going straight you’d think they weren’t even there, but man lay it into a turn and watch out!

Pete, it’s 21.5 wide, 15 nose, 16 tail, 2 5/8 thick, balsa over 1 lb eps with glass/epoxy on both sides of the balsa. Total weight with fins and wax 6.5 lbs. Rails fairly soft to 20 inches then transitioning to hard rail at 14 to tail. Pinlines by posca and finessepinstriping.com

Blakestah,

Did the Waltie swivel fin that I exchanged with you some years back, influence your new thruster/tri-fin design ?

After riding my new Supercharged-Predator/Spitfire (sorry chips, the pics didn’t come so well,will try again).I’m definiately sold on the pivot/flex I get out of my Red-X boxes installed w/ 5200 quickset marine adhesive.

I 've ridden the spitfire in 4 - 10+ face waves(5 days out of the last 7 or 8 days)…that are approx. 1/4 mile or better in length.A great testing ground for any surfboard designs… I/it only came up w/positives no negatives…so far…and the boxes + integrity of the glass and foam around the effected area(s),so far are holding-up 100%.That’s very good comparing to the rest of the board that seems to be taking a fairly strong beating, and is already starting to show some major ,“death syndrome” stuff.

I’m wondering ? how much different your design would make over what I’m doing ? Performance being first on the list,shadowed by strength factors,and finally versatility of either or…just wondering ???

Looks like you’re onto something good !!!

amazing board… beautiful as ever… how many are you at? has to be around 30?

did you set the boxes in a high density foam? i think you sold me on giving the fins a run… nothing to loose much to gain…

Great write up Shwuz,

Makes me want a set right now. Seems like they would be excel in softer waves in my 6’2" thruster fish where you pay a heavy penalty on drag. I know - they work everywhere, but this has been my focus lately, finding a good board for onshore slop, without all the butt wiggling.

How about putting a few sets up on Swaybay ?

Can you also use this set up for quads? Or other set ups? Any tests?

Definately intersted, as quad are fast already, and even less drag sound better. But, am unsure if you want both(rail) fins to rotate…?

Haven’t done any quad testing yet. I would recommend the front fins turn, and the rear fixed, in a test, and that the max toe-in allowable on the front fin matched the toe-in on a thruster. In theory it sounds like it would be better off the bottom than a quad, and faster in between turns, but you really need to do the test to see if it works.

The Waltie Swivel fin Herb traded me a few years ago is another thruster rotating fin. It uses a substantially different mechanism to achieve rotation, and lacks end-stops and pre-load to prevent oscillation. The mechanisms I’ve used in the thruster boxes are really just scaled down stuff from the single fin, I didn’t really take anything that related to the fin rotating from other designs. But I’ve a keen interest in design in general, so I appreciated the fin. Conceptually, my system is dominated by the end-stops. They are not flex-like fins that load and release. They simply stop at the angles you benefit from most in a turn, and release in between turns.

We’re still not at mass production numbers, getting more kinks ironed out so they will be easier to consume than Schwuz’ was. But it is moving in that direction, I’ll try to go faster.

burnsie, I agree with your assessment. The reviews are best in waves overhead and less. And the smaller the slop, the bigger the difference between the surfing trucks and a thruster. I have had a bunch of really excellent head high days though, I found I could make it down the line, and hit the lip vert, a bunch of times in a row, more than I could on other systems of any kind.

The system just LOVES to go vert. You carry so much more speed up the wave face between the bottom turn and hitting the lip, no slowing at all, and you don’t need to stay on rail. Same when lining up the next bottom turn. You just don’t need to think about staying on rail if the wave doesn’t demand it. You can straighten out and carry speed through sections, its a lot easier.

…if no photos of the fins and boxes are “allowed” ,

is there at least any VIDEO of the things being surfed , please , Dave ?

cheers

ben

ooooh, i am salivating like a pavlov dog…

would you pm me an idea of cost for a quad? any info on tools needed etc would be great also.

I think that you are right about the trailing fin being fixed. I went beck to the shop and looked at a few boards I have around, and put some glass ons on the bottom to see what they would look like rotating. Not that I think you would lose holding power with a rotating trailer, but i think having it fixed would create more drive, for lack of a better term, when the leading fin rotates to its toe/turning position. Is that the correct idea?

The toe setting I am using are similar to thruster anyway, leading fins at 1/8 - 3/16", and the trailers are at max 1/16."

Also, I am fascinated by what you are saying about the vertical ability of these fins. Just trying to imagine… as you drop and turn your fins are toed, then as you release the rail they straighten, then off the top they are toed again, and straighten as you re-enter? What? That is crazy(again lack of articulation)! There would be minimal, if any, loss of speed, only acceleration.

So, how fast are these fins cycling? Obviously rapidly. Do you get release of the fins, what is incorrectly called cavitation?

Thanks for the stoke.

You, as a rider, will have no idea what the fins are doing, how they are positioned, etc. I never did. I set them up parallel to the stringer knowing that the neutral force position is very slightly toed in, but that doesn’t matter, either. What matters is the end-stop for toe-in is at 1/4". The end-stop for toe-out is irrelevant. So is the neutral position. The bumper force is pretty irrelevant, too, if it is too soft you feel a little bump at the end of range, if the bumpers are too stiff the fin will not fully turn, but that is about it. The fins align to the flow, do not oscillate or cavitate, and when pushed far enough in toe-in, they stop and generate forces just like a regular ole thruster.

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Also, I am fascinated by what you are saying about the vertical ability of these fins. Just trying to imagine… as you drop and turn your fins are toed, then as you release the rail they straighten, then off the top they are toed again, and straighten as you re-enter? What? That is crazy(again lack of articulation)! There would be minimal, if any, loss of speed, only acceleration.

First, the bottom turn is close to a two fin turn, always, because the outside rail fin aligns to the flow. This is noticeable, and the bottom turn is faster than a thruster or anything else I’ve ridden. But it is because the outside rail fin is gone wrt drag.

Then heading to the lip, I just let the board flatten on the wave, no staying on rail at all. it feels like you coast up to the lip with no speed loss. Then, tear the roof off, come straight back down the face, rip off another bottom turn, repeat…

somehow that process never ceased being fun.

yeah!

"Then heading to the lip, I just let the board flatten on the wave, no staying on rail at all. it feels like you coast up to the lip with no speed loss. Then, tear the roof off, come straight back down the face, rip off another bottom turn, repeat… "

now, i am hooked…

i think i need to check this out. pm me the info, or post it here whatever is best for you. but i am definately interested in trying it out.

pm me the details for payment, too if possible.

thanks

Well, that review obliterates any doubts I once had about washing out or loss of drive–I wasn’t factoring the stop position as a standard toe-in.

Also, Blakestah, the outside rail fin isn’t toed-in during a turn, so you don’t have the overexposure of the foiled side and the pressure, or the consequent low-pressure pocket on the flat side, with all the drag, yeah? A more streamlined outside fin during the turn definitely seems like it would give massive advantage

I’ve forgotten–did you say that the tail fin is more firmly bumpered?

When will they be available?

Seems you’ve just reinvented the thruster, Dave. Do you go firmer bumpers for bigger waves, I guess?

I’ve been a skeptic about adding moving parts to surfboards, and artifical release off fins, but Jarrod’s review says it all.

Oh yeah, is the stop cushioned at all?

GREAT stuff

Hi Dave -

You know I’ve asked this before…

When will they be available?

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the outside rail fin isn't toed-in during a turn, so you don't have the overexposure of the foiled side and the pressure, or the consequent low-pressure pocket on the flat side, with all the drag, yeah? A more streamlined outside fin during the turn definitely seems like it would give massive advantage

During a turn, the water flow hits the outside of the outside rail fin. It is always “reverse foiled”. In my system this impact is minimized, because the fin will toe-out somewhat, which reduces its drag a lot.

I wouldn’t get too hung up on it though…changing things for the outside rail fin is hardly noticeable. Making it rotate more or less in toe-out, largely irrelevant. Bumper stiffness for toe-out, also nearly irrelevant. The one thing that stood out the most, by far, was the impact of altering inside rail fin toe-in. The impact of all other aspects of rotation were much less sensitive performance factors.

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I’ve forgotten–did you say that the tail fin is more firmly bumpered?

The best config AFAIAC is with the rail fins rotating and the rear fin fixed. They will be available when they are available, the wheels are in motion. The boxes let you fix any of the three fins, and let any of the three fins rotate, your choice.

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Do you go firmer bumpers for bigger waves, I guess?

The bumper stiffness is almost irrelevant. The entire purpose of the bumpers and the other little parts in there is to

  1. let the fin rotate fully from side to side guided by water flow

  2. prevent the fin from oscillating madly

  3. prevent a prominent bump at the end stop - soft landings only

With this in mind, the system is not horribly sensitive to the bumper stiffness, and I see very little benefit to having multiple stiffnesses of bumpers around. They are more cushions than springs.

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Oh yeah, is the stop cushioned at all?

That’s what the bumpers are for, to let the fin hit the end-stop with a soft landing and not a firm click.

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Hi Dave -

You know I’ve asked this before…

When will they be available?

Molded versions are being designed based on the prototypes I sent out (like Schwuz’), and feedback from him and others is critical to make sure they are rock-solid before the next step comes. But the molding hasn’t begun yet, just the drafting of the changes. It will come…