Scaling up favourite surfboard to SUP - advice please?

Hi Guys,

Probably not the most liked topic to talk about, however:

I’m in the process of scaling up a 7’6" CJ Nelson Outlier into a surf SUP.   It’s my favourite surfboard that I’ve ridden - i’ve just clicked with it…

Video of the surf board here:  https://www.youtube.com/watch?v=ZvmCdIpv76Y

I’ve never really seen a ‘hull-esque’ SUP before and there may be reasons why - that i’m not aware of just yet!  Maybe the market is just not there, but this type of design makes so much sense to me for SUP.  Easy trim and glide whilst still being able to turn.  Not super high performance, but to be honest 95% of sup surfing isn’t either.

I do have a question for the shaping experts:

As the tail is 18 1/8" (12 inches from the tail) - is it simply too wide to work as a 10" single fin?

Should I go with a single and tiny side bites or as a Twin (or twinzer) instead?

I want that fast trim feel you get when surfing the surfboard version, but I also know how easy/efficient a single fin is to paddle on to waves.

Thanks in advance for any advice / thoughts.

Cheers!

Hoppo

 

 

 

Welcome to the forum Happo.

You might want to do some more of your research and ask questions on a forum that is more focused on SUP like

Shape Shack at Standupzone.com

You may have to go back a little before they all got going on foils and stuff.  There are a small handful that post on both forums.

I have made 3 SUP’s but I don’t surf them. My daughter has one that could potentially surf but we are 4 to 30 hours drive from waves so…

Normally I hot wire EPS for the rocker/sled and then hot wire the outline and the first uppper rail band indexed to the bottom. Then the work begins with shaping and sanding. Carbon fiber on the stand patch and HD foam inserts around leash plugs and finx boxes whenever possible. All of mine are finned 2+1 but we normally run centers only.

Another item of research is to see what is being done by established SUP companies for surfboard-style SUP’s and/or talk to guys actually making and riding them and then see if you can attend a test-ride event.

All the best, J

 

I don’t know anything about SUP design but I can tell you that a singlefin will work on an 18+" tail so long as you do the bottom right. With that said, it seems to me that your stance is different on an SUP and your point of balance/trim is different. Those are factors that would play into where you would mount the fin because on a singlefin surfboard you want your rear foot over the fin  where you will have the maximum leverage over it.

Then when you add in the point that you can only paddle on one side of the board at a time and it seems to me that would be of effect on where to put your fins - directional stability while paddling on one side of the board. On the face of it it seems like putting high-aspect fins out at the rail might offset some of these. Maybe a fin+runner like ACE was doing on the Eaton’s Zinger. Or even a keel+canard like Bing’s Synchronizer (w/ProBox Larry Allison).   . But that’s all pure conjecture on my part because I don’t know anything about SUPs.


Thanks for your comments jrandy.

I’m in the process of joining Standupone, but haven’t been approved to join yet.

I’m not planning on making the board myself, I was going to get a big name Sup company that makes customs build it for me.

I’va owned over 10 HP sups and have been a surfer most of my life… Also, where I live - demo’s are not really an option.  

Ideally I just wanted to go to the builder and say, can you build this exactly.

Cheers.

 

 

 

Thanks for the advice gdaddy.

Doing the bottom right means?

Currently, the bottom is rolled at the nose, soft rail / flat bottom at mid point, soft-ish rail / flat bottom at tail, hard rail - just like CJ’s surfboard version - although we’ve moved the flat bottom forward a little to be underfoot on the standing area to aid paddling stability. 

I have usually surfed the 7’6" CJ Outlier with a 9’5" involvement fin all the way forward.

My friend who is doing the drawings for me loves twinzers and has recommended them for this SUP.   I’ve never surfed a twinzer - so I can’t say for sure if i’ll like…

It’s a bit of a leap of faith anyway with this design, to see if it will go…  I’ll probably do a twinzer set up but still install a centre box, just to give me the option.

I did have the drawing attached on my post at the bottom.

Cheers.

 

 

 

 

 

 

 

If it were my board I’d be asking these questions over at the SUP forums.  I doubt there’s much the shapers who do those haven’t yet experimented with. 

 

Ask 4 times, measure 2 times, cut 1 time.      

10" fin will work.

Awright, a few things- 

I’m in the process of scaling up a 7’6" CJ Nelson Outlier into a surf SUP.   It’s my favourite surfboard that I’ve ridden - i’ve just clicked with it…

Good. 

I’ve never really seen a ‘hull-esque’ SUP before and there may be reasons why - that i’m not aware of just yet!  Maybe the market is just not there, but this type of design makes so much sense to me for SUP.  Easy trim and glide whilst still being able to turn.  Not super high performance, but to be honest 95% of sup surfing isn’t either.

Look, 95% of SUPs are principally paddleboards. Not surfboards. They get used in ponds, or on rivers, or for fuc#ing up traffic patterns in navigational channels like the harbor I used to work at. That’s what they are made for. Not to be surfed. Don’t worry about it.

As the tail is 18 1/8" (12 inches from the tail) - is it simply too wide to work as a 10" single fin?

Should I go with a single and tiny side bites or as a Twin (or twinzer) instead?

Me, I’d say stick with the single. If it doesn’t work with a 10" fin, use a 12" fin. Fast and easy to change out and find out. You have nice hard rails back aft, that will affect things more.  Side fins or twin fins, canted and angled as they should be, will make for drag and slow down the paddling, make it less efficient. Plus you have the paddle blade, right? 

I want that fast trim feel you get when surfing the surfboard version, but I also know how easy/efficient a single fin is to paddle on to waves.

Ohhhhkaaay, it won’t trim quite as fast, after all it’s bigger. 120% the size of the 7’6", which yields more surface area, more buoyancy, the extra width will make it a little harder to turn, extra length means it will take a little more shuffling to trim…though it will be a little more forgiving that way… As Frank Sinatra sang, That’s Life - and it’s not like you’re gonna burn the 7’6" , rather it’s something you keep for those days that require a little more performance.  . 

Keep it simple, don’t overthink it. Have fun instead.

doc…