Looks like Wednesday. I am in NJ. Gonna be good here or LI, depending on the wind. We have had a really bad stretch of waves for the last month or so, which is probably why I’m obsessing about fin placement too much.
This is the “compromise” position that I had in mind. Don’t know the numbers on them, but the rear fins look about 2" off the rail but wider than McKee.
Hi Jamie, It sounds like you went thru the motions, very impressive my friend. Your comment about the sliding and feeling still sounds like board over taking fins. The boards you are showing just like the White diamond have deep concave with thick wide tails. My suggestion is your fins are to small not so much all the fins, but the rear fins more so. Most quads rears are running 3 1/4" to 3 3/4", with wide thicker boards I have experinced the rear fins climbing in size to 4" to 4 1/4", with front fins at 4 1/2" most commonly to 4 3/4" in size. Try a larger rear fin first in your board in as close situation that you can remember like before. Also make sure your plan shapes are fuller in the tip area and not rakey and thin which will also give you that wash feel in the white water. Also found to my surprise all 4 fins worked good at 6 degree cant with 80/20 foils in this set -up. Would love to hear the results before you break in the router. Buy the way your board looks very clean keep up the stoke my friend. Mahalo, Larry
Thanks, Larry. I very much appreciate this advice.
My board that I am shaping now has a single concave (about 1/8") through the belly of the board and flattens out through the fins. Tail rocker is about 2" and I haven’t fondled a White Diamond but my tail isn’t too thick. It is wide, though. (15 1/2", no wings, point-to-point on the diamond about 8.25"). Anyway, on my other board that I found some unpredictable slideyness I was using Hynson Quads, which are pretty large, front and back. When I first tried out the board, I was using PC 5qs and they were horrible. Tail totally overpowered the fins. Then I switched to the Hynsons and they were night and day better. Still, I took out the board with the hynsons in Waist-Stomach high clean beach break a few weeks ago and definitely had some uncontrolled sliding going on. Fin position on that board (a superlight, epoxy/eps 5’11" x 21.5 x 15.75 tail flat bottom) was 11.5 fronts and 6.5 rears; 1.25 off the rail for both (just like what you recommended in the pictures above). Had the backs slid all the way back in the proboxes and the fronts in the middle.
The board I’m finishing right now is a 6’1 built for small to medium waves (waist-head). My buddy has a Von Sol that he loves and he just measured the fins for me last night. They were nearly the same placement as what you recommend, BUT the rears were 2" from the rail. I’m wondering if that will take some of the slideyness out.
I just ordered some Rusty Quad fins last night which are pretty large area (not as large as the Hynsons) with large tips and I’m hoping they go good on this new board.
Jamie, What kind of fins are you using FCS base or ProBox base? Epoxy and wide you are riding on top of the water which also explains the slide. If you move the rear fins off the rail of the board, it will change feel to the tail instead the rail. Which will take the slide out but possibly feel tracky or stick on backside and at the top of the wave.
Something to think about when the board is over taking the fins in a quad world. Change the pivot point and move it back. Take your front larger fins and put them in the back at 6 or 8 degree cant then put the small fins in front at the same degrees. This will take the slide out and give your board more direction, keeping the cluster close together, back fin forward and front small fin back. If the board is stiffer and you can't correct this way, your fins are to small. Change to larger fins with larger fin in front and smaller in back again.
In your set up now move your front fin all the way back also keep your back fin all the way back.
On wider, thicker tails the quad cluster will be back further than more pulled in tail plan shapes. The same with wider and thinner tails in epoxy boards because the epoxy board is riding higher on the water than a poly, so sliding is more apt to happen.
Hope this answers some more unknown thoughts my friend.
Mahalo, Larry
Thanks, Larry. More good stuff. My fins are FCS base.
This new board (that I’m contemplating fin placement on) is a PU US blank with Epoxy resin.
The old slidey one was EPS/Epoxy and super light. Your explanation makes sense on that one.
Just what I thought, you were using FCS based fins. When you have more power pushed to the FCS the flex from the tip to the base will also give you that unpredictable feel. The flex is traveling all the way to the bottom of the fin. Having a ProBox base tranfers the load to mid point of the fin only always giving you a solid base foundation with the bottom of the board.
I would like to do a test with you. Send me your favorite fin template in FCS. I will make you the same fin in ProBox. If you don't feel the power different in the 2 fins, I will take the ProBox fins back at no charge to you. Even thro your FCS fins fit in ProBox and has all the adjustment features, its still a Twin Tab fin with the power section cut out.
Interesting to see your thoughts (feel) with this test.
Mahalo, Larry
Larry,
Sounds like an offer I can’t refuse. Let me try out the Rusty Quads (they come in the mail tomorrow) and I’ll let you know my favorite.
RIDE REPORT
I finished the board last night and took her out for a maiden voyage today in REALLY GOOD chest-head high clean NJ beach break.
For fin placement I went with the rears 2" off the rail and 5" from the tail with 3/16" toe. I rode the big red Hynson Quads. Fronts were 11.25" and 1.25" off the rail with 1/4" toe.
In a word: stoked.
Board went great, fins were solid on the steep drops, off the bottom, and predictable off the top and in cutbacks. No surprises, and that’s what I wanted.
So far, I only went right/frontside (southeast swell), so the jury is still out on backside. But I am really happy with the results so far.
First time riding a PU blank in a while. Board is definitely heavier and sits lower in the water than all the EPS boards I’ve been riding. But no complaints. I was worried I left too much foam on the front end when I shaped it, but after riding it and paddling it, I’m glad I kept it beefier.
NIICE Jamie! sounds like it all came together. board looks clean too.
please report if/when you get some backside waves
Rode it again today in very small knee-waist high glassy surf and managed to get a few lefts backside. Definitely hit the bottom-end of this shape in terms of wave height/power (not a full-on groveler) but it did feel pretty smooth going backside. Nothing weird. Have to get it out in better waves, hopefully next week.