thanks for posting this. I bought the pdf of this whole interview. Interesting, but most of the talk is spent explaining the shortcomings of the high performance thruster, rather than talking to him about twinzers.
I had an osmosis twinzer in 1993 made by Mark Leverage, hes in noosa now retired,
Im trying to make the fastest board on the planet again, this might be the extra sprinkl.
I can’t call this a “Twinzer” exactly. Two single plugs set to the rear and just inside of the forward fins on what would be a normal Thruster set up. Closer to a C-5 I guess. I wanted a small pair of fins of the same foil, but had to settle on a Twinzer pair from Rainbow. Lowel
Hey guys,
Making my 2nd Twinzer. One guy i respect wrote me this, totally different from the “flow over back fin” design…,
" But this is not what I consider a REAL twinzer as the idea behind a twinzer is not to try and direct the water flow onto the back fin, instead it is to smooth out the twitchiness of a regular twin fin. This is one of the reasons the fin is so canted, it’s role is to serve as a transition onto the back fin and to smooth things out a little.
I exclusively ride twinzers on my boards and I have for many years now as they really loosen up a long board and give it a lot of speed. "
Probox Larry wrote about this too, with the front fins being canted at 18’ from flat horizontal [or box+extra]
Anybody out here tried this set-up?
Cheers
That’s an interesting take on the twinzer phenomenon that I have not heard before BUT makes perfect sense…
I have not tried the extreme cant on my twinzers.
I run 2* mains and 8* canards iirc and I LOVE that setup. YMMV
I had one twinzer once. I hated it. And it was a Rusty. I figured they knew how to build these things. But after measuring, it was just a standard quad with the small fins forward. I’ll have to give this design concept another look.
We’ve seen some setups that consisted of a twin + bonzer runner mounted at the bonzer cant. The comment was that they were more about carving than turning but I think that might be due to the long base chord and channel, not the cant.
Like i said before, my favorite setup for a fish is a small keel + twinzer leader @ 10*. You get all the drive of a keel except that it holds and is real controllable on your backside.
how would the canard “smooth things”?
If things=water flow (to prevent cavitation), then that’s the same as directing water onto and pressurizing the main fin so that it doesn’t cavitate (= holds).
I was lucky enough to speak w/ the man himself Wil Jobson in person, but our conversation never went to the purpose of a canard, unfortunately.
My Jobson had fins up at 8.75" and canted at 11 degrees (canards) and 4 degrees (mains), but I have to make mine at 8" and 8/2 just to get the same kind of hold as his. His boards have a special hold that I have never felt in any other shaper’s twinzers. You can move the fins back to get hold, but then you lose the drive you get coming off a deep bottom turn that you get w/ fins further up. I’ve recently discovered this.
Howzit ghosty, good to see you posting here. Just curious: how do you like your griffin versus your best personal shape? How do they compare ride-wise? Did finishing and riding one of Greg’s designs affect your thinking about the design in general? ( I figure it has to have on some level, but interested in your observations.). You’ve been a pretty noteworthy advocate for twinzers.
Chao.
Uncle?
I gotta say that thru the years this thread or discussion of “Twinzer” fin set ups is one of the most enlightening discussions ever. Lowel
Since the Surfer forum has died. I think it’s time to bring this tread back to life. Hopefully some of the regulars will return.
Back in the mechanism discussions of the Thrailkill Twingle. Hans likened the effect of the Twingle to that of biplane wings.
IMO the Twinzer setup/layout is more like biplane wings than Thrailkill’s Twingle — half of the wings on the left side of the board and the other half of the wings on the right side.
First, the old WWI era biplane wings were often staggered relative to one another (top wing forward for improved stall characteristics). “Biplane wing stagger, where the top wing moves forward (positive stagger), varies but a common beneficial amount is around 0.4 of the wing’s chord (length), significantly improving aerodynamic efficiency and lift compared to stacked wings.”
And as I recall, biplane wing separation was/is approx. one (wing) chord length separation (balancing lift and drag).
It would be interesting to test performance of a Twinzer setup/layout that has been modified to separate the fins by one chord length of the fins. Outside fin staggered/overlapped forward. Fins with a more uniform width (chord length) would be needed. Outside fin would be the equivalent of the biplane top wing. Fins with asymmetric foil, flat side facing in/center.
The de Havilland Tiger Moth
To readers and posters my only comment is; Be wary of over “toe” or “cant “ both. Going back through this thread, looking at some of the pics. A few of the setups seem a little skewed. The old rule of using a straight edge to insure you are not over toed is a good rule. Some of the pics look like they were beyond center. A couple of them look like the cant is also pretty extreme on the outside fin.
Thankyou for this, there does seem to be a lot of variation on fin angles and distance from tail . Its interesting to see so many points of view about this type of set up .