If you want to beat Twinzer ideas around here’s the spot.
Love 'em ~ Hate 'em ~ Bash 'em ~ Tout 'em ~ Show one?
Go for it!
No Worries, Rich
I owned a Larry Mabile Twinzer fish for a while, it was very fast and loose, so fast you could make it further down the line in small waves than a standard keel fish.
It seemed to carve through turns without acelerating or decelerating, just retaining it’s speed.
I have to say this was one aspect I didn’t like, I love that drivey feeling of projection out of a bottom turn that I get with Bonzers and keel fins or quads.
I remember on one clean shoulder high day, I got back out of the water and switched it for a Bonzer egg. That was more fun. Horses for courses.
I notice that the lead fins are almost the same size and template and the rears in Greg Griffins 5 fins.
I can’t post the pic, but it’s on the link below
Rich, thanks for starting this. I’m a quad convert now, so I am very interested in the full 4 fin notion.
I have a twinzer I have not ridden in a while. Maybe it is just the fin placement (little fins forward), but I’ve been thinking, doesn’t this arrangement have some things in common with Herb’s super chargers and the C5 thing? So there is more going on than meets the eye?
Hey Greg,
You’re right on with your observations. The lead canard on a twinzer and Herb Spitzer’s “Superchargers” so very much of the same thing. Promote laminar flow. Put the main drive fin in a wake so less turbulence is created.
Sizing and placing fins on a twinzer is super important. I would not choose to have two large rail fins. I believe that the small/big arrangement is best for rail application.
The quad is a completely different animal even though it has four fins. The fins are placed very differently than a twinzer with the lead fins place much the same as a truster cluster and the trailers more foward than a truster trailer but well off the rail line. Thus the board has more directional stability but isn’t as snappy.
We see massive variations in fins placement with some boards being a hybridization – quad/twinzer – somewhere in between the two.
No Worries, Rich
“We see massive variations in fins placement with some boards being a hybridization – quad/twinzer – somewhere in between the two.”
Kinda like this??
Im very interested in trying something like a twinzer setup. Ok, so the above is just a twin keel with some SC’s whacked on, but it definately paddles faster, and i feel it “releases” better, oh did i say fast? haha. Would like to try a twin fin ( not keel ) version, on a shortboardish/modern fish shape. I notice on twinzers, the lead fins seem to be bigger than superchargers, and also further away ?
Hi Halcyon, Thanks for this thread I hope you don’t mind this post of a Twinzer set-up. I find having the conard fins vertical works against the rear fin which makes the board ride stiff. These fins are at 18 degree can’t to work with the rear fins which gives the board a looser feel, which is similar to a Blue Hawaii Twinzer set-up. Mahalo, Larry
Larry, I’m glad you posted that and explained that. Thank you and Rich for providing insight on this fin configuration and pics too!
g
I absolutely love mine, if this board snaps I’ll have it copied.
There’s one! Is that one you did, Blt? Have you any ride reports? That’s more the thing I was talking about with the multi-element deal–you’d have to have significant interaction there!
The twinzer thing is an option I wanted on mine, but my fin clusters came back from my glasser much more spaced out than we’d talked about–I guess he had a change of mind on it and gave me much more of a McKee setup than the close-spacement I’d had in mind.
Any of the fin gurus have some intel about how spacing the fin cluster on a twinzer wider or tighter affects the ride?
I’ve had some discussions with various people over the validity of aerodynamic and hydrodynamic comparisons. Some say that air and water are both fluids in a sense but others say air is a gas and no comparisons are valid. I like to think that comparisons are indeed valid but necessarily directly.
In any case, I often think about the similarities of twinzer designs and my own experiences with sloop rigged sailboats which use the slot effect. With the sails, there is a definite relationship between the main and the jib which can be altered dramatically by changing the shape of the foils and the distance between the sails.
Here is one guy’s attempt at explaining what’s going on. It is part of a much bigger site that examines other aspects of boats which may or may not relate to surfboard design. I leave that to the reader to decide. Also note stuff on composites…
http://www.arvelgentry.com/magaz/Another_Look_at_Slot_Effect.pdf
http://www.sailboat-technology.com/links/online_articles.php
Wil increases the cant in the lead fin also, but not that much, I measured one of his shaped boards. It is nice, if you want to make a Twinzer, to have some idea of how the fins were placed by its inventor. I believe he has worked with Rainbow and you can probably get more up to date info from them. But the standard was the twinzer fin was 1 3/8" from the main fin (as in the size of the “slot”, there was 3/8" overlap between the rear of the twinzer and the lead of the main fin, and the twinzer fin was canted slightly more.
Wil told me that the lead fin was there to promote flow attachment on the inside rail fin. A significant other role of the lead fin was to promote a wash on the outside rail fin, which operates at a negative angle of attack - and that this wash acted to minimize the drag on the outside rail fin. He updated the twinzer main fin (but not the canard) to a twist fin in which the base was singly foiled and toed in with standard toe, and the tip was 2 degrees less toed in and doubly foiled.
The Great Spirit didn’t make too many people like Wil.
His boards rode like very fast twin fins. Souped up twins. They could grab a high line and hold it very well, trim very fast, a little sketchy if you wanted a deep bottom turn, but turned quickly on cutbacks.
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from the Dynamic Balance 7’0" board shaped by Wil Jobson, number 1614. The board has a 14.25 inch tail, looks kinda gunny, I’m guessing 1993-95, only one channel each side, the center concave is there but subtle compared to later models.
Main fin:
fin has a standard “dolphin” shape like most current thruster fin shapes.
Base width: 4 3/8" plus glass rope
Depth: 4 7/8"
Toe-in: 1/4" on the 4 3/8" base
Distance from tail to rear of fin: 8 5/8" not including glass rope
Distance from rail to center rear base of fin: 1 1/4"
Cant: I didn’t have a proper tool. Looks 3-4 degrees
Twinzer lead fin:
Toe-in: parallel to main fin
Cant: 2-3 degrees MORE than main fin.
Distance from rear of board to rear of fin: 13"
Fin base: 2 3/4"
Fin depth: 2 3/4"
Fin has a raked ellipse shape
Perpendicular distance from base of main fin to base of twinzer lead fin: 1 3/8"
Overlap from twinzer to main fin, measured parallel to the stringer: 3/8"
Twinzer is mounted WITHOUT FIN ROPE, so that the fin makes a sharp edge with the deck. Wil felt this was important on the twinzer lead, but not on the main fin. He mounted them in Q-cell plus resin, and there is a lot of ding repair work remounting them (the ding repair guys usually use fin rope).
I think Rainbow can supply these fins. If you want to make them or have someone make them I can get the foiling. The main fins are flat inside, foiled outside, and rounded leaded edge, I think you can still get them from Rainbow - Wil used to get them from Rainbow, and the same people still work there.
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This is interesting stuff. I always look at the thing about a lead fin or wing “cleaning up” flow to a wing or foil behind with skepticism though. The color guys on F1 broadcasts–not the actual aerodynamicists–say things like that. If you have an overall amount of area, I can’t see how you reduce the work of getting through a fluid overall by moving one amount of resistance to another place a couple of inches (or feet, in the case of F1 cars) forward or aft, but hell I dunno.
I like that wash/attachment thing. It seems to me if lift is an overall redirection of flow off a foil, the back side flow has to stay attached to promote the lift wash off the trailing edge.
I can’t take credit for the board, I picked it up in San Diego. Shaper is Chris Herel, I’ve only seen 1 other board like it in my life. I’m actually going to try and copy it, I just haven’t gotten around to shaping the 4 blanks I have in the garage.
I personally love the way it surfs, much faster than my thrusters while holding much better than a traditional twin.
Quote:
There’s one! Is that one you did, Blt? Have you any ride reports? That’s more the thing I was talking about with the multi-element deal–you’d have to have significant interaction there!
I have two Hynson twinzers. Fastest boards I’ve ever ridden. Fastest boards at this length I’ve paddled. Fun.
Got any (lots of) pics?
…i used to love riding my ‘Bushfire fish’ with small front side fins and bigger back fins . With the abundance of side plugs on that , and the ‘prawn’ , i could move the side fins closer together or further apart , especially when using ‘one tabber’ side fins …
i’m thinking , when my 6’5 byrne [thruster] and the 6’4 [thruster] blank are finshed , an extra side plug or two , will allow me to try the twinzer setup on those , for a [non-‘fish’ template] comparison …
cheers !
ben
[now i’ll go and try to find the original will jobson twinzer photo that i posted here so long ago [wish me luck] ]
edit …
…there are some ‘twinzer’ type setups photos in some of these threads , too, by the way …
…the originator?
will jobson and the twinzer …
…cheers !
ben
…and , there are a couple more here …
cheers !
ben
[the blue tint ones held in really well . i like the front side fins at half the size of the back side fins …]
own a Larrry Mabile 6’6" twinzer, shaped for Kane Garden.
came with the FCS fin set that Larmo designed for the board. I switched out the small, single-foil leading fins for
double-foil fins that are the small trailer fin in a FCS MRX set of fins. the change was noticeable and improved the boards turns.
the board flies fast and turns on a dime. works well all over the San Mateo Point area and surrounding wave zones.
the board changed my surfing life last year, and I would consider another one [maybe go to a 6’4"] in a heartbeat. Larmo shapes nice boards!!!
Twinzer Love
Quote:
…the originator?
will jobson and the twinzer …
Great pic chipfish, classic.(-: Mahalo,Larry