Bert, Tom, Rich, others: fin question

Would love to hear how you guys think I might slightly modify performance by tweaking fin specs on a board that is “so close”. The problem is a slight “fraction of a second” delay in coming off the bottom turn on some waves, on a basic ASP type 6’2 x 18 5/8 x 2 5/16 squashtail thruster that has good rocker. It doesn’t “turn on” until waves are head high, but then it flies, but on some waves it’s just a half beat slow coming up. The waves are fast takeoff tropical reef waves. I think there may be a touch too much foam in the tail, as I have to put a bit more pressure on the initial bottom turn, but I hate to bail on it if it can be tweaked. What would be your fin selection to try to solve this with regards to rake, height, etc for both front and back fins?

It sounds like you’ve probably got a fairly rakey template in there right now. You might try going with something a bit more vertical for quicker response in smaller waves. How much is very relative. But, if you take a big side fin template like the XT-1’s with a tiny trailer as being the quickest and least stable set up as one extreme. And, X-3’s spread wide apart as the most stable drivey setups. There are a whole lot of combinations in between.

I’m only looking to try to get a faster initial “up into the pocket” off the bottom and only on some waves is it a problem. The combos I’ve tried are: three uprights, and then longer uprights up front with a smaller raked in back. The difficulty with this wave is that the bottom turn must both be quick and long. I’d guess that seems to eliminate all rakes (longer throw but too slow) and all uprights (quick but not enough down the line throw). I haven’t tried it yet, but would rakes in front with an upright in back be any better, or worse (theoretically)?

You get pivot from bigger side fins and drive from a bigger center fin. I’d go with bigger 4-5/8" to 4-3/4" side fins and a medium center fin 4-1/2" to 4-5/8". Then I’d start moving my side fins forward until I got the rail engagement I was looking for.

Are you perhaps losing a little pop as the fins flex? Maybe try a stiffer fin set the same size? Some of my most responsive boards have had more vertical fin templates and stiffer flex. Maybe a more vertical fat tip template relative to what you’re using?

John’s right stiffness has a huge impact on how fins feel. The new “Next Generation” Red X fins I just made are made from significantly stiffer material than our original composite series.

Hey Tubedog,

If you’re surfing Red X fins and you want a more instantaneous feel off the rail four things will amp the quickness up 1) bigger rail fins, 2) moving the rail fins foward, 3)down-sizing the center fin, 4) closing up the fin cluster. Lots to play with and as always options are infinite.

Good luck, The options of which fin to choose is better left to Tom. The 82/20 foil he has ready for next year will make a huge difference in quickness, smoothness, downline speed and drive.

Mahalo, Rich

aaahhh…more fin self education…thanks Tom.

“I haven’t tried it yet, but would rakes in front with an upright in back be any better, or worse (theoretically)?”

In Slater’s amazing surfing at the 2003 J-Bay, he rode rakey AMs front with his signature white dot center. His best wave of the event was a wedgey tube ride off the take off…snappy bottom turn into the barrel…then more down the line barrel action for a perfect 10 score.

Greg Loehr stated b4 that longer depth fins are a little more difficult to rail…keel affect…you also state you need more drive/projection of the bottom…maybe what you need are TC Redlines up front…stiff, drivey base, shorter depth. I saw Jimmy Rotherham ripping it up in ES on a critical tubey wave using those fins. That guy is freakish.

I think rakey side fins with a vertical trailing fin might work well in steep fast waves like Back Door where you’re taking off sideways and not squareing off your bottom turn.

I am no expert on fins and stuff but could this be rider error…or perhaps this a new board and you are not quite use to it’s slight performance quirks… some boards just take a longer time to adjust to…

Ship, fins can make so much difference it’s incredible. IMHO they make up at least 50% of a surfboards ride. I agree with most here that a smaller back fin in smaller waves will probably do the trick in this case. Maybe even as small as 4". Depends on wave shape i.e. if the waves are a bit soft. The softer the wave the more you can decrease the back fin. Larger sides in a soft wave will increase drive and snap.

Thanks everyone… and thanks Greg for adding your comments too…I agree fins can make a big difference. I was just a little stumped on this wave cuz it’s not soft. Think a little slower than when I’ve ridden Maalaea. And overhead to double overhead. Thumping, throwing, definately not soft, so a small trailer fin does not seem a good option.

Quote:

Ship, fins can make so much difference it’s incredible. IMHO they make up at least 50% of a surfboards ride.

Ditto.

Is there somewhere on this site where the experts who post here tell what are the things that can make a thruster setup different, what changes happen with different variations?

I’ve got RedX in two of the four T.Patterson boards I’ve got and I have noticed significant changes in changing fins and positions, but I really don’t have a good understanding on what I could do to change the ride by fin movements or different fins.

TD, I recall Bert talking about a delay wrt fins…I think it was wrt AOA and leading edge radii.

Years back I had a shortie with a troubled bottom turn. I noticed that the hard edge along the rear rail was sharp AND long. So I took some fine sandpaper and softened shortened it down…that seem to improve things. Maybe you’ve got too much release (in good/epic surf) off your rail and the board’s not holding on a timely basis. A softer rail would prevent this and sanding down a sharp edge is easy.

Glenn, Greg L posted a good writeup regarding fin setup…search his postings. Also look at postings from Tomatdaum, Blakestah, Halcyon. It took me about six months to figure it all out including foils…Im still learning.

its the board…

i agree with the other responses about what each fin set will do , what it will give and not give …

in this case some of your comments make me lean towards the board …

the first thing that comes to mind is the width 12" forward of centre …

how you describe the delayed bottom turn , is typical of an outline that carries a touch more width forward , combined with a clean outline free of bumps or hips …

the fact the board flies when it gets bigger denotes it feels comfortable drawing longer lines …

drawing longer lines is not what you want , when you see a piece of smashable lip straight above you , you wanna go straight up there and hit it …

a board with a drawn clean outline doesnt wanna go straight up in an instant , its almost like you need to program in a destination time , not quite the super responsive feel you want …

if that outline is combined with a fraction extra rail volume , then forget the fin option …

it points back to board …

if it is the board , and its like i described , fins can help , but it wont solve the problem completly with out comprimising somewhere else …

ive read other stuff youve posted before tubedog , how youve described how your board felt in certain parts of the wave , from those decriptions , its obvious you can surf and you want the most sensitive performance out of a board …

so ill leave it there till i know what the rest of the board looks like …

regards

BERT

Thanks Bert- as usual, right on. I respect your understanding of what makes a board go. It is the board; I haven’t had time to measure the wide point yet, but there is a touch more thickness forward and perhaps the wide point too. It does have hips though not much. I just tried the largest most upright fins available for the system, effectively moving the leading edge 1/4" forward while keeping the back the same, and it seemed to somewhat address the problem by increasing drive off the bottom and up into the pit, but it’s still a beat delayed and not quite completely the feeling I’m looking for. Otherwise, once up it’s fast, carves hard and really quick. I like the way it goes except for this delay. It might be the design or just this certain board. I might order same exact specs and see. It’s not off by much, but it is irritating.

thicker rails will decrease initial response time …

so now i know your board has subtle hips means it will still turn off the back foot in the pit …

so sounds like the main drama is still the straighter section of outline at the front foot …we use that part of our outline as we start to initiate a turn , if the wide point carries forward , it feels like the board wants to draw a longer line as we put it on the rail , so once your on the rail for a period of time , then as your weight starts to shift onto the back foot does the board start to respond a little tighter …the delay comes from the time we first lean into a turn to having to be on the back foot more than usual before the board finally responds …

if that is the problem , then one of the other symptoms will be the fact that sometimes you will blow the ocassional top turn by overshooting the mark and not getting it to hook around in time youll surf off the back of the wave …

also when doing full lip bash reos you will have a tendancy to go a little later and get the whole tail to leave the water to make a tight turn rather than pulling a hook under the lip …

if either of those 2 scenarios are happening more frequently , then it points to outline forward of centre …

regards

BERT

"if either of those 2 scenarios are happening more frequently , then it points to outline forward of centre … "

Yes they have, but it’s been somewhat fun overpowering those tendancies. But now I know all of these riding characteristics with that bit of wide point forward, then I think I’m going to abandon it. Just not the usual predictable results. Thanks for once again putting it so clearly.

yea ive had boards like that to , that in some conditions i surfed them real well , with an overhead wave that was fast powerful and clean .

i remember one board that when i surfed it in those conditions i could power up the most amazing lip destroying hacks …

but at the end of it all the board lacked versatility …

i still see the board around the guy loves it , but i want alot out of a board …

i reckon if i didnt make boards and had to buy them , i would be a shapers nightmare …

i would say “” just give me a board thats light and strong , fast and loose , sensitive and positive , hold in, in power and still slide when i want it to , twitchy and skaty but still forgiving , go vert but still carve long lines…“”

thats not to much to ask is it ???

for me board design comes down to gaining the most by giving up the least …

its always comprimises …

i just want the best performance with the least comprimises …

does that board still have a place in your quiver??

or are you off it all together now???

regards

BERT