Went through around a dozen pages of archives, and still I’m wondering what would work best. I’ve removed old keels and will be retro-fitting a 5’9" fish as a twinzer. I’m fairly set on position relative to swallow tips/ trailing edges, etc. So far I’m planning on 5 degrees for the smaller forward fins and 4 degrees for the mains. Should I keep cant the same or mix it up a little? This template is very low rocker, flat to vee bottom, 20.5" wide 16& change in the nose and tail. Any help would be great. Thanks…
FWIW, Larry Mabile set his mains at 6 and the smaller ones at 10 on the KG’s…
JJR,
Helpful as always- Thanks for that! My positioning is off a Larmo template, but I didn’t have my angle tool when I visited my local shop for some measurements. Hope your fall is off to good start.Laters…
from an old measured board…
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.
HTH…
Blakestah- Thanks ever so much for those dims- from the twinzer god himself. I’m going to fcs plug it because it’s the only system and jig I have available to me. I already have the fins from an old larmo I sold finless a few years back. I’d love to go lokbox and have a local shaper who uses this system, but I’m looing forward to doing it on my own. I truly appreciate all your time and effort to get me those specs. Do good and good comes back to you! Later…
There are many schools of thought when it comes to twinzer fin set-up.
The guy that dreamed it up in the first place, Wil Jobson, sets his canards at 10 degrees and the drive fin at 2 degrees with the leading edge of the drive fin barely aft of the trailing edge of the canard. Joey Thomas, Vince Broglio and Mark Going set the canard at 4 degrees with the drive fin again at 2 degrees. Some guys like to scale up the lead fin a little and down size the trailer and use full sized boxes for both fins. John Mel does some twinzers this way which have evolved from knee boards to stand up boards.
More vertical fins will be more pivotal when turning. More raked fins will have more power. For a board without much tail rocker I would tend to go with Wil Jobson’s cant and hold the Canard close to the the drive fin. Lots to consider when you’re suiting fins to a board. Some many variables it’s super hard to make the right call without seeing the board up close. One thing is sure the board will livelier as a twinzer than as a keel fin.
Mahalo, Rich
What’s the theory behind the setup? I don’t think it’s just the similar surface area of a keel with added looseness, but since there are fin gurus on the thread, is there an accepted explanation?
The smaller canard usually has more toe, so you get a bit of venturi effect. The added angle of the canard helps break up the water around the larger main fin creating that bar of soap in a bathtub feel on cutties and some lift through the turns. Acts like a larger base but without all the grab of a large based keel…
What's the theory behind the setup? I don't think it's just the similar surface area of a keel with added looseness, but since there are fin gurus on the thread, is there an accepted explanation?
When I saked him, Wil Jobson said the small lead fins helps keep water attached at the fin base of the inside rail fin during hard turns.
And on the outside rail fin it creates a wash that reduces the outside rail fin drag.
There it is. The downwash off the front fin flows over the main fin to keep the boundary layer from separating so you don’t stall the foil
Is he around still?
There it is. The downwash off the front fin flows over the main fin to keep the boundary layer from separating so you don't stall the foilIs he around still?
Ooops, I realized I typed saked him instead of asked him…
He’s been an elusive character for a lot of the last ten years. I don’t think his RV gets good high speed internet.
I think he has left the building, again, until further notice. But if you are surfing northern Washington state and run into a skinny tall bearded 60-something year old guy with five fins on his board, you may have found him and his Neomorph fin setup. He re-designed the twinzer main fins (using a fin twist similar to the one Halcyon came up with)
and added a rear fin.
A longtime core surf buddy of mine was a huge Twinzer fan (I think he has 7 or 8 made by Jobson and 1-2 that he had attempted duplicated) and I had a chance to BS with him the last time he came down from Washington…after about 2 hours of talking about fins (including Trux) he started talking about alcohol fuel injection and jet design for airplanes and motorcycles…Jobson has a home-made alcohol injection system in his vehicle that results in nearly zero SOx and NOx emissions and is also a speed freak.
Very into details and engineering and design, very smart, and more than a little eccentric. A pleasure to meet.
What’s the rear fin on his personals look like?
What’s the rear fin on his personals look like?
It probably changed since the last time I saw it…
Those are the “new” rail and twinzer fins. But they were further up, closer to thruster fore-aft positions (I didn’t measure it in front of him - ha! ) and there was a hatchet-like rear fin.
All five fins are aligned, in Wil’s mind, on a “power ellipse” that runs inside the rails around the tail.
He also had re-done the rails with a tucked under approach that looked hard to shape - but he said he has a series of rail templates for different distances up from the tail.
That fin cluster seems to be around. What is the deal about the rails?
Hopefully this being Wil Jobson’s personal board, this is still somewhat on-topic
Yo,
FYI: Wil Jobson is shaping at the North Coast Stables, which is about a mile north of Western Dr. on the ocean side of the Rt. #1. The shaping room is shared by Mark Goin, Joey Thomas and Wil. Wil is in the shaping room Tuesday, Wednesday & Thursday. Mark is there the other days of the week. Joey is in Central American for another week. Vince Broglio does all of these shapers glass work. The crew does both EPS/Epoxy and Poly/Poly construction. For anyone interested this is Twinzer heaven with three top shapers who all ride twinzers and a full on pro glass/tow-in man sheathing the boards who rides twinzers. Vince and Richard Schmidt are town in partners and ride Twinzers exclusively.
Note: Mark and Vince just did an 8’0"x21.5" EPS/Epoxy twinzer for me. It’s double 4oz bottom 4/6oz deck. It weighs less than 10lbs. I have an accurate weight next week. I’ll get some photos and post them. Fins for it in the works.
Good Waves, Rich
P.S. You want twinzer fin and foil theory Wil’s the man. All you have to do is have the time to listen.