Posted on Leave a comment

All about SUP River fins

Focus on iSUP fins

Demystifying the fin thing

We put together a blog article last year to demystify paddleboard fins.  We tried to turn all of the jargon into a short, simple article that anyone can understand, even if you don't have a degree in fluid mechanics.

Since then we've been contacted by lots of people asking for more advice about fins.  So maybe we didn't do as a job as demystifying as we thought. But those searching for advice are often asking about river fins.  This isn't really surprising. It's the fastest growing component of paddleboarding, and one of the most neglected by surf and windsurf focused brands.

So we went away and thought long and hard about the type of SUP fins that our inflatable SUP customers need for river SUP. And we spoke to our customers, our partners and friends, to make sure we really understood what people really needed. And then we went away and found a supplier for exactly the type of fins that most iSUP customers are looking for.

But first a reminder about why fins are needed (apologies if we’re teaching grannies to suck eggs, but don’t forget, there are newcomers to SUP every day who might not have heard this before!

Fins have two main purposes:

To help you stay in a straight line.  If you’ve ever paddled a SUP without fins (yes, we’ve done it as well, arrived at the put in, pumped the board up, and realised we have no fins! [1]) you’ll know how difficult it is to track in a straight line. With a fin in place, the fin counteracts the drive of the paddle, stopping the tail of the board swinging around. The larger the surface area of a fin, the easier it is to paddle your SUP in a straight line, and the more difficult it is to turn. It’s not quite as simple as this, with other factors such as length and shape coming into pay. If you want to find out about the factors, then you want to check out our earlier article.

To slow the board down.  This might seem counter intuitive if you’re not a surfer. But the side fins (also known as 'bites' serve to ‘bite’ the wave and provide a focus to pivot on. Surfing with a central single fin is preferred by surfers who prefer gentle and graceful carving. But if you want to slash and hack, then you need a different fin arrangement. With three fins in a thruster arrangement being the most common.

If you keep these two key purposes in mind for the rest of this article, it should all come together by the time you've finished.

In addition to satisfying these two purposes, there are a few other key requirements for river SUP:

Interchangeability

Interchangeable standardised fins
Interchangeable fin system

The most important requirement was that fins should be interchangeable between all sorts of boards, not just between McConks boards [2].

All of our centre fins are compatible with all universal centre fin boxes (often called US fin box).  Every decent brand in the world uses these on their premium range of boards – Red Paddle, Starboard, Naish, Fanatic. And this applies to the quality UK brands as well – Fatstick, Loco, Freshwater bay.  If you’re not sure if your board has a universal box, take a photo of the box, or a fin that fits the box and send it to andy@mcconks.com, and we will let you know if your box is compatible.   

Our 2” side bites are compatible with all FCS fin boxes, and also with the Kumano and Suru surf click fit system. 

Flexible

In general, the stiffer a fin is,  the better the performance. This is true for both centre fins and side fins, as any surfer will tell you.  This is great if you’re paddling your SUP in deep water on the sea. If you’re in shallow water, fFlexible finins have an annoying knack hitting submerged rocks. Or catching on the river bed.  The best outcome is the rider is catapulted off the front of the board as it comes to an abrupt and unexpected halt. And narrowly avoids knocking themselves out on a rock. Stepping up the damage scale, if you’re using stiff fins, you’re very like to snap a fin.  Stepping it up further, you could crack a fin box, or a rip the fin box off the board, causing expensive or irreversible damage.   And right at the top of the damage scale, you could be catapulted off the board walloping your helmet or a flailing limb against a very hard rock. And the possible outcomes there are pretty sobering. Especially if you're in serious whitewater.

So for whitewater paddling, or shallow river paddling, you should always use soft flexible fins. These take much of the impact of rock strikes, and they flex as the bump along river beds. This gives you a flying chance of staying on the board, and reduces the risk damage to the fins, your SUP board, or you.  

And even endurance river races such as the #Trent100 start off in shallow river sections that would benefit from flexible fins. Several competitors this year said they wished they’d started the event with a range of fins, including some flex fins.

The other requirements were more fin/discpline specific….

Centre fins for shallow water racing

After speaking to competitors in some of the endurance river events, it became clear that there was a desire for a flexible, indestructible SUP fin that:

-         Has a large surface area and race foil for effective straight line tracking

-         Has a strong rake on the leading edge that clears weeds and other detritus effectively

-         Is robust enough to take knocks and bumps from rocks and shopping trolleys, but strong enough to maintain its shape in normal conditions

Blue river flexible SUP fin

These fins are 10” long, so provide great tracking.  And digging so deep provide significant stability and directional benefits in cross wind / cross surface chop conditions.

And for the fashion conscious, we even do them in two colours (going against our normal rule of keeping it simple!)

Centre fins for deep water racing

In river races not in shallow water, the benefits of a stiffer fin come into their own, and there's little need to compromise with flexible fins. 

This 8" carbon fin has a strong rake for weed clearance, and the cutout allows for swift pivot turns if needed, whilst still allowing for excellent tracking.

Centre fins for whitewater / river SUP

This is the first of our superflexible short river centre fins.  This SUP fin is only 5 inches long, which gives you 3 or four inches more clearance than the fins that come as standard with most decent SUP boards with removable fins.  These are an awesome compromise between tracking, weed clearance, and speed.

The second is a shorter 3” fin, but with almost the same surface area as the 5” fin. We do this by having a very long fin base (takes up the whole length of a standard US fin box), and by extending trailing edge of the fin well behind the fin box.

2" Whitewater side fins

These fins fit all FCS box or Sauru surf / Kumano surf click boxes.

Extending behind the box, these have a surprising amount of surface area for the fin depth.  Use with the 3" or 5" centre fins for a perfect whitewater SUP setup.

Go and have fun

River fins haven't had the same amount of R&D that surf and open ocean fins have received.  So this is a relatively new and exciting playground.

Get out there with different fins, and see what works for you.

Tell the world via SUP hacks if you have experience or comments on what works for you.

If you've got ideas on what would work for you, but doesn't exist yet, speak to us. We like prototyping new products for our customers!

Notes

[1]      This is the ONLY good thing about fixed SUP fins. You can’t lose them or turn up to paddleboard without them. In every other way they are inferior to removable fins and detract from your objective of having fun on the water!

[2]      Our 2” river fins will fit the click fin boxes on Badfish SUP and McConks SUP, and any SUP board with FCS fin boxes. So if the mood takes you, you can even shove three 2” fins in your FCS thruster set up on your surf board. By extension this flexibility applies in reverse to our inflatable SUP boards.  There  are a massive number of SUP fins out there that fit our boards.  And this is the real benefit of having a universal centre fin box – the huge amount of choice.  Any universal fin (including FCS connect) can be used in the centre box.  So you can check out fins from Black Fin Project,  or FCS or Futures fins.  Or from any of the very many aftermarket fin resellers out there.

Posted on Leave a comment

Go with the Flow. Making whitewater SUP easy

Go with the Flow!

We've had an exciting couple of weeks testing our new whitewater SUP.  As everyone surely knows by now, inflatable SUP are the best SUP for whitewater.  Being so rugged and robust, yet also very light, nothing beats inflatable SUP in whitewater.

And just to prove it, here's a vid of Team GB freestyle stuperstar Matt Stephenson using the board at the whitewater centre in Nottingham (Holme Pierrepont, National Watersports Centre).

When we set out designing our whitewater board we gathered a team of whitewater experts, from the kayak, canoe and paddlesport fields, and asked them what was missing from current boards, and how current boards on the market needed to be improved.

And the responses we got then underpinned our design.  The most important features were:

  1. A wide stable platform, with a deckpad that extends all the way from the nose to the tail to allow movement around the board.  Or so they said.  We think the real reason was to provide added protection for the 'transition movements' between standing and swimming.  We've designed our board to be 36" wide and 9'8 long - the length is a compromise between longer length for stability and forward momentum, and shorter length for river surf and manoeuvrability.  The reviews we've had from our prototypers, which range from experts to beginners have confirmed that the width and length provide huge amounts of stability when on whitewater and the design, in particular the rocker profile and the hard edge, allows it to still be really maneuverable.  One tester commented that it had an unprecedented amount of secondary stability for an inflatable board.  Heady stuff!
  2. Handles.  Lots of them.  These serve two purposes.  Firstly, handles in lots of different locations are good for self recovery and protection.  No matter where you are in relation to the board, you need to be able to reach a handle.  And this needs to be true for shorter people and beginners as well - more than one awesome female paddler pointed out that handle placement on all other whitewater boards made recovery more than challenging for them.  And secondly, they need to make it easier to get the board into and out of the water, and up and down steep river banks. Of course, this needs to be balanced against the risk of entrapment, and so the handles need to be reasonably tight to the board to prevent feet getting trapped.
  3. Full length deckpad.  The deckpad covering the whole board is a massive confidence booster giving you somewhere soft to land, whilst enabling you to paddle the board backwards if you get in a real pickle.
  4. Rocker and waterline.  The board has been designed by computer modelling, and then optimised through protoyping to ensure that the board is amazingly responsive but stable no matter where you stand (or are thrown to!) on the board.  Although this board is not a specialist river surf board, the sporty progressive rocker allows riders to drop into waves, and the responsiveness of the board when on a run allows you to get to those waves when you see them.  The stomppad and tail rocker shape means that the tail is responsive and easy to sink despite the board's width.
  5. 4+1 fin boxes and proper river fins.    The centre box is a standard US centre box, meaning you can use pretty much any aftermarket fin you want.  And the side fin boxes are FCS compatible click fit boxes from Kumano.  That means you can use normal FCS fins if you choose.  But why would you want to with the fins that come as standard?  We provide three centre fins, 8", 4.7" and 3" depth fins, all flexi and capable of withstanding significant bumps and scrapes.  We've reduced the depth on the 4.7" and 3" fins to reduce the risk of that 'superman' moment when fins catch a rock.  But we've maintained overall surface area by sweeping the fin behind the fin box.   And the same is true for our 4 x 1" side fins.  These have a very low profile, and large surface area for the depth due the swept back profile.

And we also spoke to riders about paddles, and how paddles could be improved.  And almost universally they said carbon shaft, polypropylene blade.  The carbon shaft for stiffness and the polyprop blade for robustness and damage protection in rocky waters. But they also wanted to be able to have a carbon blade or fibreglass blade for when touring.  So we came up with an interchangeable blade system that allows you to choose what blade you want in your carbon shaft.

And just to prove yet again how easy this all is, here's another vid of Matt Stephenson showing us all how it's done. And a more realistic video of a whitewater SUP noob demonstrating that anyone can have fun on the right boards and right conditions!  In fact, in one of the boards trial runs at the National Watersports Centre, a total SUP noobie (experienced whitewater paddler, but had never stood on a SUP before!) managed to run all of the features but one without swimming.