custom 14' questions

[GlideMarko]

Any thoughts would be appreciated:
For 14' flatwater custom SUP - How wide can you with tail to gain as much stability as possible and not jeopardizing speed to much? Is there any formula how much curve has to be in the second half of rail lenght? As pointy/'displacement' nose already pushes water away is there any curve even needed besides longer water line? 
example:
14x24 with 15' square tail width  vs.
14x22 with 18' square tail width
Would 3' wider tail cause more drag than gain glide of a 2' narrower board?
From my limited experience, wider tail did not cause more drag and narrow board was simply faster...

Cheers, M

[burchas]

Which board are you riding right now? Do you have any reference as to what are you comfortable with?

My 2 cents would be, go with a wider board and make the tail as efficient as possible. Every speed
machine I've seen has a pintail so that should tell you something, many times they even come with
rounded bottom. Obviously these boards can be challenging but if I would be up for one, I would
try to  balance somewhere in between.

I've ridden same shape boards side by side with one being a 26" and the other 24", one inch tail
difference and I can tell you that speed difference was almost non existent for me.

One thing I've noticed with speed machine with rounded bottoms is the addition of the Larry Allison
4 fin setup to "control the roll" and giving you the extra stability, so that's another consideration.

[GlideMarko]

thanks for that!
currently i'm on 2017 SB 14x23 (with 15.7' tail)
so if I go 14x22 with 18' tail.... ? I wonder how it will go...
well I did it on 12.6 - and it worked... wide tail and the board still flies.at least feels like good speed for 12.6, but could not compare to other 12.6

[supuk]

Generally I have found most stability benefits come from what's in front of your feet rather than what is behind.

[GlideMarko]

here's some pics how was my 12.6 custom

[burchas]

thanks for that!
currently i'm on 2017 SB 14x23 (with 15.7' tail)
so if I go 14x22 with 18' tail.... ? I wonder how it will go...
well I did it on 12.6 - and it worked... wide tail and the board still flies.at least feels like good speed for 12.6, but could not compare to other 12.6

2things:

- It seems like your only reference are "All Water" boards, a compromise by design.
- You don't reference any GPS speed readouts so I have no way to have real world speed reference.

Going by feeling can and will be misleading often times. Since you did specify it is a flat water board
You should at least try a flat water specific board and compare it with a GPS readouts to your fast board.

The board in the pics seems to be geared towards flat water (measurements please and bottom shape too).
I'm not sure why are you going with a 14 if that one flies, but I would definitely suggest to go in a different
direction if you'e really looking to have a meaningful gains in speed.

[TallDude]

Generally I have found most stability benefits come from what's in front of your feet rather than what is behind.

I agree. Generally speaking, that's why people move back on the board when the water gets rough. By moving back, you put more wide area in front of your feet. The board typically feels more stable there. It usually doesn't track well, and the nose moves around, but it feels more stable. I personally don't like wide tails. Better for buoy turns, but not something that I do regularly.

[GlideMarko]

yes, i look for fast flatwater board
well, 12.6 was made for Copenhagen Worlds (for long distance race) as I could not get any decent board in short notice.
Most races in Europe are on 14'sa and therefore I have chance to replace sprint with custom, but need even faster design but with the same stability.
And I thought that would be the easiest way do go narrow with wider tail... I know, I know, train harder is another way, ha  :-)
just loaded shot v12.6 videos
https://www.youtube.com/watch?v=MDrwfeI3g5w&feature=youtu.be
https://www.youtube.com/watch?v=YNx9LvEHeOg&feature=youtu.be
Thanks, M

[Eagle]

Having paddled the 2017 Sprint 14x21.5 -> would remove the chamfered edges and go back to the triple concave 2016 All Star design for a custom.  Would cut the little bobble you get when you put full power down.  So sacrifice a touch of speed for a touch more stability.

Notice how the 2018 Sprint essentially has come full circle back to the original 2016 AS design.  So basically would get a custom Sprint with full length cutout in a 14x21.5 with the 2016 AS simple clean triple concave bottom profile and width at the tail.  Would motor on flat with plenty of glide yet be more stable and wicked fast.  21.5 is super efficient and makes the 23 feel somewhat draggy. 

[GlideMarko]

so, it began.. .custom 14x22' with 38cm (15') tail

[Bean]

Generally I have found most stability benefits come from what's in front of your feet rather than what is behind.

That's interesting, I would have thought the opposite.  Based upon my experience with the Simmons shape which seems to make any board more stable, and conversely, the K15 shape, fast but initially twitchy.

Certainly the balls of the feet (as opposed to the heel) are where most of our natural balance is.  So that could create an illusion that stability is coming from up front.

[TallDude]

Generally I have found most stability benefits come from what's in front of your feet rather than what is behind.

That's interesting, I would have thought the opposite.  Based upon my experience with the Simmons shape which seems to make any board more stable, and conversely, the K15 shape, fast but initially twitchy.

Certainly the balls of the feet (as opposed to the heel) are where most of our natural balance is.  So that could create an illusion that stability is coming from up front.

Being stable standing still in a lineup is very different from being stable while at speed. Think of a gun design which is better at holding a line at higher speeds. When ever you want to go the fastest down the line, you move forward. When I'm in a race, I move forward to trim the nose of the board. If the nose is narrow, it gets vary unstable. The outrigger designers have more recently been moving the paddlers closer to the nose and putting more volume forward. Here is the latest Pueo Forward Footwell design. 

[jrandy]

Thanks for sharing and looking forward to seeing the rest of the build GlideMarko!

[GlideMarko]

Progress... 12kg/m3 foam being cut/shaped

[GlideMarko]

Bottom ready and vacuum glassed