I hope the guys at surfer design forum don’t mind …
I found THIS helpful …
(I hope others do, too ! )
cheers !
ben
sorry to “talk to myself” , but today I was talking to a mate on the phone ,who shapes on the south coast here , and funny enough , he mentioned his latest personal board was actually …
11" x 6’3 x 18 1/4" x 2 1/4" x 13 3/4".
FINS were what interested me more , though…
4" deep futures back fins, at 5" up from tail tip [“baby swallow”…he didn’t remember how wide]
4.6" deep futures front [side] fins, at 13" up from tail tip …
A QUAD setup .
Just thought this might also interest someone else out there .
[Russ usually just shapes wafer thin rockery thrusters for himself and all his customers , apart from the occassional “mini-mal” / “funboard”].
ben
Chip,
I think the front fins are about an inch and a quarter too far up. The key with a quad (not Twinzer) is that the back fins are not set a certain distance from the rail, but set a certain distance FROM EACH OTHER. Usually 5 to 6 inches trailing edge to trailing edge. Cant should be 95 degrees front fins, 93 degrees rear fins. Toe front fins 1\4 inch, toe rear fins 1\8 inch
this is a good place to start.
C
That’s interesting feedback , Cantellya …thanks for that .
…is there a quad website or templating info place or something, or did you just find by experimenting, that is the setup that works best for you in your waves ?
Russ actually commented to me that he felt he needed the fins that far apart [I assumed , maybe wrongly, that a thruster kind of distance would be fine] , because he found that closer together , the board felt too loose . Which , to me , could have been to do with the rocker and the fin sizes , too ? [Also , the waves where he surfs have HEAPS of GRUNT …Russ is a charger !]
So many variables …
that’s why I think it will be fun to play around with more four fin setups than this on my ‘prawn’ this year…
…having those extra plugs , and a back finbox , to allow lots of fin movement , will be a bonus !
ben
Chip,
A lot depends on the fins you choose, but this setup has been the most reliable. I even use double sided foiled rear fins sometimes. Really smooth turns but a little less drive. I don’t know how many great quads we got rid of in the 80’s due to improper fin placement. That was still glass on fins. BIG nightmare for sanders!! When FCS came out we started playing with quads again. I took a board with no bells and whistles (concave, etc.) and put fcs plugs in all over the place to really see what was up with fin placement on the SAME board. VERY INTERESTING!! Moving the rear fins farther from the rail was my biggest surprise. The board was much more vertical, slight drive loss (but still way more than thrusters).
I’d like to see some of the Pro’s get on some new age quads for sure. I think this the only design at the moment that would allow them to surf close to their normal thrusters without falling out of favor with the judges. This would be the first step in getting off on a different direction. (it’s time!)
C
Oi Chip & Cantellya!
Just thought I’d chime in on the quad theme. After becoming totally infatuated with my 5’8 quad, I wanted to see how the setup works on longer boards and in bigger surf. So, for my recent Indo trip I shaped a 6’8 gunny swallowtail with very much the same quad configuration that Cantellya quotes, except my rear fins are double foiled and only toed in the tiniest smidgen.
We arrived just as a very solid swell hit, and got to surf long, hollow double oh+ waves for a few days. The board was a dream to ride, very drivey, very solid, no spin outs, and so much faster than a thruster. Right off the bat, it felt like an old friend.
So if anyone is wondering about the validity of the design for drawn out plan shapes, my admittedly limited experience says it works great, and I’ll be doing much more experimenting.
Cantellya, could you maybe elaborate a little on your ideas on the rear fins (toe/no toe, single/double foil, amount of cant etc)?
Cheers
Maz
Mazzy,
Good on ya with that Indo trip! One of these days I’d love to surf there.
Anyway, Very important to have front and rear fins not on the same angles as far as toe and cant unless you want tracking problems. There are so many ways to approach it. The front fins are pretty much the same as the side fins as a thruster except you want them up a little farther. The rear fins want to be less toed in. 1\8 inch max on a base of 4 3\8. Cant can vary according to taste but what is important is that when you sight the fins looking at the bottom nose to tail that you see a noticeable difference in the cant angles. Not much, but some. Maybe 2 degrees. I like 5 for front and 3 for rear. Yes, by all means try back thruster (double foiled sides) fins for the rear fins. As I stated earlier it has a nice feel in turns! DO NOT try to set the rear fins perfectly parellel. When you do this you run the risk of negative toe in. When you set the fins if you’re off 1\32 inch in the wrong direction, you’re f#cked. this is easy to do when you are connecting the dots and have the thickness of the pencil to deal with. 1\8 is just safe. When I shape keel fishes with parellel fins I always toe 1\8. an eighth over a 7 inch base is minimal and is good insurance.
Good luck with your shaping!
C
Hey Cantellya.
Thanks for the reply. I think I’m with you re fin placement. Thus far, I’ve gone as follows on all my quads:
Rear fins; minute toe-in, 4dgs cant 5 1/2 to 5 5/8" up.
Front fins; toed-in to a point 3" either side of nose, 7dgs cant, 11 to 11 1/4" up.
I.e., I spread the cluster out a little more on longer boards than on fishes.
All my boards have double foiled rear fins, and I wonder if there’s a big difference from single foils. Obviously, you can screw up big time if you set single foiled fins dead straight or with even the slightest toe-out.
The quad set up seems to suit my style (!?!!) of surfing perfectly, so I’ll be doing much more experimentation on exact placement, size etc.
Keep us up to date if you come up with new info/ideas, eh?
Cheers
Maz