Author Topic: What are the limits of step rails?  (Read 2815 times)

exiled

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What are the limits of step rails?
« on: March 24, 2019, 06:24:36 PM »
So way back in the day, Carl Schaper (2007?) stuck step rails on the old Southpoint Bonga Perkins SUPs, but it didn't exactly take the industry by storm.

The concept got worked into the Jammer from Supsports, but didn't make it into later models.

Sunnova has a super tweaked out version on the Shroom, but not any other model?

Now Portal is using it with all of their models, and infinity is rolling it out in the Blurr 2.0

It seems like such an obvious design choice that I'm wondering why it hasn't been more popular? Why not just shape 5 inch thick boards and step the rails down?
« Last Edit: March 24, 2019, 06:31:58 PM by exiled »

TallDude

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Re: What are the limits of step rails?
« Reply #1 on: March 24, 2019, 06:40:04 PM »
It's kind of a double edge sword. Kings boards have had them for a while. I've surfed a few and found them very tippy compared to a similar width board with 50/50 or tapered rails. The concept is it reduces the at edge volume, which can give you a harder turn with better hold. Aside from the tippyness, I find the board dips or bobs right and left near the nose when I am just paddling it straight. The boards I tried were lower in volume for me. 120l to 140l range.

exiled

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Re: What are the limits of step rails?
« Reply #2 on: March 24, 2019, 08:31:29 PM »
Low enough volume so that the rails were under water?

TallDude

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Re: What are the limits of step rails?
« Reply #3 on: March 24, 2019, 08:45:27 PM »
Low enough volume so that the rails were under water?
One of the King's I tried...yes. My short board is mostly under water as well, so it's almost an apples for apples. The other Kings I tried was a longer, maybe 10' x 29", so about the same as my Coreban Icon. That was the one that paddled funky. It's like it slips sideways right and left under water.

Dusk Patrol

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Re: What are the limits of step rails?
« Reply #4 on: March 24, 2019, 09:03:43 PM »
JP Australia uses a step rail on its Fusion line. I  thought the purpose was to keep the deck flat but still have a decent thinness to the rail. The Fusion boards are big enough that the step isnít submerged any more than other boards.
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surfcowboy

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Re: What are the limits of step rails?
« Reply #5 on: March 24, 2019, 09:04:33 PM »
Plus one on the tippiness. TallDude you have a gift for explaining things. I could never put my feelings into words but thatís what I felt when Iíve demoíd Kings step rails. Just a bit out of my reach.

TallDude

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Re: What are the limits of step rails?
« Reply #6 on: March 24, 2019, 09:16:24 PM »
This was the lower volume one I tried. I remember the wind had come up and chopped it up. I was struggling on the board.

exiled

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Re: What are the limits of step rails?
« Reply #7 on: March 24, 2019, 09:35:02 PM »
Interesting, I ask because I've also heard from some guys think generally that having the rails underwater adds to stability.

TallDude

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Re: What are the limits of step rails?
« Reply #8 on: March 24, 2019, 11:24:03 PM »
Interesting, I ask because I've also heard from some guys think generally that having the rails underwater adds to stability.
The further out you can push the volume, the more stable the board. A domed deck progressively decreases the volume as it gets closer to the edge. The stepped rail carries more volume out closer to the rail via a flat deck, but then rapidly drops in volume in the last 2" on the rail. The average volume of the outer 6" of the two different rail types maybe very similar but it's really how much volume is at the rail the ultimately determines stability.

eastbound

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Re: What are the limits of step rails?
« Reply #9 on: March 25, 2019, 03:19:52 AM »
my portal doesnt seem any tippier than comparable boards ive tried--might be im just used to it---but were the portal way tippier, id notice

my L41 had stepped rails, and was very stable, but that was more about width and wide tail/nose than rail shape
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burchas

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Re: What are the limits of step rails?
« Reply #10 on: March 25, 2019, 05:23:33 AM »
Interesting, I ask because I've also heard from some guys think generally that having the rails underwater adds to stability.

I read mixed opinions about this one. It comes down to personal experience imo.

My 10'x31"x4" @ 150L has fully submerged rails almost throughout the length of the board. I find it very stable
even though I designed it for my self at 175LB (wishful thinking) and I ride it now at over 200LB with winter gear.

It does make it a significantly slower than other shapes I've tried without submerged rails.
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RideTheGlide

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Re: What are the limits of step rails?
« Reply #11 on: March 25, 2019, 06:56:08 AM »
Interesting, I ask because I've also heard from some guys think generally that having the rails underwater adds to stability.

I read mixed opinions about this one. It comes down to personal experience imo.

My 10'x31"x4" @ 150L has fully submerged rails almost throughout the length of the board. I find it very stable
even though I designed it for my self at 175LB (wishful thinking) and I ride it now at over 200LB with winter gear.

It does make it a significantly slower than other shapes I've tried without submerged rails.

I am a relative novice, only a year into SUP, but have swapped out with others and paddled a lot of boards. I find submerged rails give me good stability by being unstable in slow motion if that makes any sense. IOW, when I got off balance I had more time to recover.
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PonoBill

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Re: What are the limits of step rails?
« Reply #12 on: March 25, 2019, 10:27:29 AM »
I'm not a fan of domed decks, they make my ankles ache, but I like thinned out rails, so stepped is good. On my L41 it made the board challenging to stand on, the sweet spot for balance, both in pitch and yaw, is tiny. But it carves turns with a feel that's hard to express--I aim to be able to feel that locked-in sensation on a foil once I get past the "whee, I'm flying" stage. Which is taking much longer than expected.

The Foote Triton has stepped rails too, though its of a style that's also hard to explain and it gives the board tight turning ability that a 10'4" board shouldn't have. The rail looks full at the nose and tail because it tapers upward as the rocker increases. I think it makes the arc of the board tighter than the rocker line and let's it snap turns even with my weight somewhat forward. The King board above has similar rails, though not as pronounced and the effect is probably minimized with the blunt nose and tail. The Foote certainly doesn't carve like my 8'8" L41, but it does turn like something in the mid 9' range rather than a 10+ board. And of course with all that length and width stability isn't an issue.

I've certainly noticed the stability effect of having the board under water. My 6'11" foil board hasn't got a lot of volume in the nose, so if I'm not paying attention it sinks under water a few inches. It's stable like that, and I only fall off the board when I look down, see it's buried, and try to get it up to the surface. I'm learning to ignore the "problem" and just focus on getting into position to catch a wave. I discovered if I catch a wave with the nose buried that it makes no difference. The board still planes along even if the deck is awash and a quick pump outs me on the foil just fine. Most of the challenges of foiling have to do with learning what matters and what habits to break. This is a tough one, but watching Junya get onto an well-overhead wave with his board completely underwater helped me understand that a sunken board works fine--it's the frantic efforts to unsink it that toss me off.
« Last Edit: March 25, 2019, 10:39:20 AM by PonoBill »
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supnorte

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Re: What are the limits of step rails?
« Reply #13 on: March 25, 2019, 12:04:03 PM »
I've been surfing for the last couple of weeks with the new Infinity Blurr V2 7'8 x 25.5 with 79.5 liters.
I'm 1,80 and 73 kg. My previous board was the Infinity B-Line 7'11 x 27" with 85.6 liters (and I was used to surf with plus 95 liters boards).
My surf exploded when I started with the B-Line: less volume, great outline, thin rails and even thinner tail and nose.
Despite there was only a difference of 5 or 6 liters in volume (and when you're surfing with low volume board every liter counts), there's a huge difference in terms of width and specially outline, with a shortboard-like nose (I'm finding it great for critical lip manouvers), narrower tail and even thinner rails (like a shortboard).
The step rail as allowed to pack some extra volume on the center of the board without sacrificing performance and was the main reason for going for the Blurr V2.
Here's a few photos that show the step rail:


Dusk Patrol

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Re: What are the limits of step rails?
« Reply #14 on: March 25, 2019, 12:13:47 PM »
The Infinity and Kings steps are much more pronounced than what I experienced on the JP. The JP seemed like such a good idea I wondered at the time why it wasnít more common.  Itís a more restrained approach, for less performance oriented board.
« Last Edit: March 25, 2019, 12:16:46 PM by Dusk Patrol »
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