Fin forward vs smaller fin back

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Fin forward vs smaller fin back

Postby benjl » Wed Jul 05, 2017 9:42 am

I have a question for you longboard gurus..

What would be the differences between say a 6" fin placed right forward in a fin box vs a 5" fin placed right back in the fin box?

Which would be loser? Which would have mor hold? Drive? Pivot?
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Re: Fin forward vs smaller fin back

Postby Big H » Wed Jul 05, 2017 10:46 am

Like everything else it depends.....the shape and width of the base of the two fins, tail rocker, tail shape, width and thickness, size, shape and cant of the side bites used in conjunction (I'm assuming in that the fin size would suit a 2+1). All things being equal, fin forward to the nose is looser, back to the tail stiffens things up. The reason I have an ever growing fin box of all shapes and sizes is that the only real way to find out what works best is to try it out. Look into getting one of the centerbox screws that are fitted with a finger adjustable wingnut. You can flip the board in the lineup and move the fin forward and back during your sesh to test different positions apples to apples under the same conditions.
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Re: Fin forward vs smaller fin back

Postby Big H » Wed Jul 05, 2017 11:03 am

Fin forward generally less drive and back for more drive....again the fins themselves play a part (total area, base width and for the pivot vs more drawn out turns the rake).
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Re: Fin forward vs smaller fin back

Postby Big H » Wed Jul 05, 2017 11:08 am

Pic of my new longboard and its massive 11.25" pivoty skeg. Definitely felt different than the greenough 4-a I usually use.....fell off the first two bottom turns I made because it just grabbed....no flex or spring. Differences and learning through application.
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Re: Fin forward vs smaller fin back

Postby waikikikichan » Wed Jul 05, 2017 11:22 am

One fin which will solve two problems........ just get a 5 1/2" fin. Then you can place it in the center of the box for normal conditions, back when the wave get bigger/clean and forward for peaky/choppy.

Does the 5" and 6" fins have the same template ? Usually a more upright template is more pivoty/loose. While a more rake fin offer more drive. But also don't forget the composition of the fin ( FRP, CF. Fiberglass, honeycomb composite ).

If it's for your SUP, i would go with Quads over Box single.
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Re: Fin forward vs smaller fin back

Postby benjl » Wed Jul 05, 2017 7:57 pm

Hey guys, please assume the fins are identical.
That's my question..

I already know all of the other factors.

I read that a guy took the stock 140mm centre fin off and swapped it with a 120mm fin in the same position. I was thinking why wouldn't he just move the fin forward? And then it got my thinking to my original question..
Would the smaller fin further back give the looseness and hold compared to the bigger fin further forward in the box which would give loaned but maybe less hold
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Re: Fin forward vs smaller fin back

Postby Big H » Wed Jul 05, 2017 11:35 pm

I sometimes use a 2+1 in the performance longboard I have....usually when the waves are big or if I'm surfing a fast and hollow wave and need drive and traction....I had a 7" cutaway I used with side bites (I forget the size) and then a 6" cutaway of the same shape and fibreglass build came up for sale on the local used page so I got that to try and I had similar amounts of drive and hold but the board was faster to paddle/less drag. Maybe that's the reason.
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Re: Fin forward vs smaller fin back

Postby benjl » Thu Jul 06, 2017 5:05 am

Just finished up a sup in my biggest and most challenging conditions yet. 2m, heavy wind, a lot of water movement, dead low tide and heaving west coast swell.
It was an immense struggle to stay balanced and I was the only person out on the entire beach- there were barelling breaks all down the beach. I tried to post a video of this a frame breaking in to a peeling left but it was too big so here are a few photos.
I only got 2x waves but the first was solid overhead and I made several nice turns and a decent ride.
The second I was stuck at the lip for ages due to the heavy wind- finally just dropping down as it closed out. The nose was just scraping the water and I had to really get my weight on the back foot to avoid pearling- I actually thought I was going to get barrelled!

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Re: Fin forward vs smaller fin back

Postby billie_morini » Sat Jul 08, 2017 6:31 pm

benjl wrote:I have a question for you longboard gurus..

What would be the differences between say a 6" fin placed right forward in a fin box vs a 5" fin placed right back in the fin box?

Which would be loser? Which would have mor hold? Drive? Pivot?


Wait! You are using fins?

:?
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Re: Fin forward vs smaller fin back

Postby oldmansurfer » Sat Jul 08, 2017 7:28 pm

There are lots of factors that go into surfing. The board design and fins theoretically affect how you surf however it is still about how you surf. For instance you can buy the best board/fins for doing airs and still can't even catch a wave with the board if you are a newbie. You can get fins that are supposed to give a lot of drive but get none from it because you have to do the right thing with the board to get drive. I think just trying it out is the way to see how it affects your surfing. The most important part of surfing is the surfer and their skill. You may find you enjoy some placement of the fins or that you can adapt to whatever fin placement or that you can't notice any difference. A while back when I had restarted surfing I was using a 9'6" longboard. I suddenly felt like I made huge progress with my surfing and was carving some amazing turns with this board then noticed that the screw had fallen out and the fin was sliding all over and tilting or whatever it was doing but I liked it so I left it like that for a while. It started making loud banging noises when I surfed bigger waves so I figured that can't be good and bought another screw but I bet someone could come up with a fin that tilts and gives way and moves around and some people will enjoy that. So many variables in surfboard design (and fins) :) Funny thing too is that once I screwed the fin in I could still carve that board really well but it wasn't quite as loose.
So what is worse.... dying or regretting it for the rest of my life? Obviously I chose not regretting it.
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