it seems to me that there are 2 main schools of thought on quad fin placements. 1 - trailing edge of rear fins closer to the rail with similar toe-in as the front set. 2 - trailing edge of rear fins further inboard towards the stringer with less toe-in (mckee type set up)
my question has to do specifically with canard style quad set ups and the pavel speed dialer set ups. it appears to me that these type of fins are designed to work together in a specific fashion. so will these fins work equally as well in either of the above placements? do the designers of these fins have recommended placements for the individual set ups? can i just replace my current quad fins with canards and still get the intended ride characteristics?
There are no hard fast rules for the way four fin boards have their fins placed. Each shaper will do things a little differently. Generally when both fins are placed near the rail and fairly close together the fin set-up is intended increase rail lift and drive but has to be moved back toward the tail to create sufficient directional stability so putting very large full based lead fins on a fin placement like this can create excessively twitchy and unstable performance. There are several ways to size fins placed like this but one can only make the call specific to a given board.
When the lead fins are placed similar to that of thruster rail fins and the trailers closer to the center of the board and fairly well aft the lead fins are generally 4.3/8" to 5.0" deep and the trailers seldom work well if they are over 4.0" deep as deep trailers will interfere with rail to rail transition.
I’ve tried the canard quad fins on a quad that has the mckee placement formula, and it wasn’t the best setup for me. It felt like there was a big loss in drive with the front and rear fins so far apart… too much water washing through. I put in several different combinations of all kinds of single and double foiled fins, and I think that the canards had the least amount of drive and least amount of snap of all the setups. This board was a more modern shape with a few subtle nods to the fish… like slightly down rails, a bit wider and flatter… but shallow single to double concave and a battail.
I just made a speed dialer and set the rear fins 7" from the tail and front fins 12" up - both sets 1 1/8" off the rail.
Only surfed it once so far during the Hanna swell and it was real fast and stable frontside but I had a little trouble with that set up riding backside.
I moved the front fins up 1/2" in the ProBoxes and it performed better for me.
Looking forward to taking the board out again and dialing it in.
i dont have a quad that i was intending to drop these into. i guess my question was kind of misleading, my appologies.
i am just planning out the next few boards i want to do, as well as what fins i am designing each shape for. i was unsure if i could just use my layout guidelines from previous boards, or if i was going to have to modify them for these fins
i havent used a canard or speed dialer set up to this point. as you pointed out, these set ups are designed to work in unison but i wasnt sure in what proximity they needed to be to have the intended performance.
if you dont me asking, what did you use for the toe-in and cant figures for the front and back set-up. and did you get these measurements from someone/where in particular, or by trial and error?
also, thanks for the pro-boxes. got em in, now just waiting for some swell to try em out… maybe sunday??
One key element that goes with the canard/speed dialer setup is the double to single concave bottom and deep swallow tail. I suppose you could try them on a different bottom config, but Pavel’s done his homework.
I toe’d the fins +1 3/4" off the nose. 8 degree inserts up front 6 degree in the back.
I chose the toe in to keep the speed but give a tiny bit more turning since my style is based on quick pumps to the high line of the wave (or so I think that’s what I do). Position and cants were suggested by ProBox Larry.
I’m planning on playing around with the positions and cants this weekend if this forcasted swell shows up.
Gonna change out the fins too and try some new bamboo ones I just made.
hey man, thanks for taking the time to reply. when you describe the bottom contour on the pavel, you said it is a dbl to sgl concave. i havent had the opportunity to look at one myself, so i’m assuming (and you know what happens when you assume) that it’s a dbl concave through the mid-section into a sgl concave between the fins. is this correct?
thanks for the added info brian. hope to get out in the water on sunday to get a ride on the proboxes, but its my sisters b-day so it may be a no go this weekend.
I’ve tried the canard quad fins on a quad that has the mckee placement formula, and it wasn’t the best setup for me. It felt like there was a big loss in drive with the front and rear fins so far apart… too much water washing through. I put in several different combinations of all kinds of single and double foiled fins, and I think that the canards had the least amount of drive and least amount of snap of all the setups. This board was a more modern shape with a few subtle nods to the fish… like slightly down rails, a bit wider and flatter… but shallow single to double concave and a battail.
NJ_surfer, I agree with you about the Mckee formula for Quads not really bad but I guess a better word is limited. Because in single overhead surf front side down the line people like the Mckee formula. But this set up is extremely hard to surf backside and recover out of a cutbacks. Below is a board that Barry Vandermeulen shaped for a good surfer out of the South Bay
who made the comments in performance as I stated above.
I was sort of expecting Larry to have chimed in on this one as he was just yesterday
putting in new boxes on a quad that was using the McKee formula because the owner
indicated that the board just wasn’t working right.
I’ve been hounding him about quads lately, having built a wide diamond tail quad and
a quad fish recently.
As I understand it, McKee puts the rear fin further back from the front and much further
off the rail than the setup that Greenlight mentions above (which is just a hair off the
placement I’ve been using [1 1/4 off rail]).
Quads are supposed to have the fins positioned in such a way that they are working
together, ESPECIALLY the canard quads where the canard is priming the flow for
the rear fin.
Do you have any measurements or pictures of your current set up?
You are right afoaf, Quads work best has a cluster of 4 together. Here are picks on the same Barry V. board for a true test. Notice the fins in the board, I think the pics speak for themself. This board turned into a complete different board with a larger surfing range, frontside and backside.
The double concave is carried through the mid section, and the single is “out the back,” meaning the doubles start fading out ahead of the leading edge of the front fins, and are gone by the leading edge of the rear fins. Between the rear fins it’s pretty much single only.
It would be fun to play around with where the single starts and the double ends. A longer double (carried further back) compared to a longer single (double ends well ahead of the front fins)…could be an interesting comparison. It’s been my experience that on a traditional, modern shortboard with a single to double, the less single you have (longer doubles), the more drive. The more single you have (shorter doubles) the looser the feel, but with less drive. I don’t know if this same logic applies to a double to single, though. Maybe it’s reversed?
In any case, all of the concaves are relatively shallow. You don’t need to go too deep if you already have a fairly relaxed rocker.
I think the swallow tail is more forgiving backside than that diamond would be. That’s a lot of tail area on that board, and with the leverage disadvantage on the heel side, you need some kind of relief feature in the pod… I put a battail on mine, but mostly, you see swallows. It took me a while to find the right fin setup with the McKee placement, but now I’ve got it nailed and I’m loving it… RFC’s R4s in the front, matched up with FCS’s FG5s in the rear. Great setup for me in local waves from just overhead down to waist high.
BTW… can’t wait to pop in my first set of Proboxes give them a test drive. Greenlight Brian hooked me up.
