Rudder upgrade

Hey guys,

I rarely paddle in legit downwind conditions, but I did a race this past weekend in conditions that were pretty sloppy. Wind was 10-15 knots  with gusts over 20. Wind driven chop was 2-3' and against the current so it created some unstable bumps. On the downwind legs I got in some nice runs but there were several times the tiny Epic weedless rudder just wasn't cutting it. I think a larger rudder would be helpful for conditions like this. I reached out to Don at DK rudders and he provided a lot of good info.

What rudder would you recommend for choppy messy conditions like this? It's for an Epic v10g3.

I assume you are using the epic weedless with the epic weedguard, as it is not weedless rudder without it. If that is the setup you are using, i would just get an epic surf rudder. It is a very good rudder and it is designed to mate perfectly with the same epic weedguard that you already have on. That is my preferred system on any ski. I too do most of my miles with a weedless rudder. The epic rudder is unusual in that it requires that big weed guard. But what you get in return is in my opinion the best handling weedless rudder out there. Unlike all other weedless rudders, it is perfectly balanced. Most weedless have almost all of the rudder behind the shaft, so they take more effort to steer. Even more important in regards to performance, i think, is the near vertical lead edge of the epic weedless. It allows crisp and precise turn initiation. Other weedless rudders are very slow to respond if you are actually surfing with them.

Bottom line - for all my epic skis I have used epic weedless and epic surf, always with the weedguard on, and I love that system.

For all my non-epic skis and k1 i have bought DK weedless rudders. DK’s product is outstanding, the price is very reasonable, and he fills orders amazingly quick. i might have 10 DKs by now.

If on the other hand you have an epic and do most of your miles with a surf rudder, but prefer a DK surf rudder over the epic surf rudder, then I would  not bother with the epic weedless as using it would require applying and removing a big epic weed guard.

Hope that makes sense. 

For anyone reading this who finds the epic weedguard falls off, you should either glue it on or use 3M or Gorilla double-sided foam mounting tape. The adhesive on the epic weed guard is too thin to conform to a round surfski hull. I have lost enough weedguards that I just make mine from scraps of plastic and hot glue. 

Finally as testament to my love for the epic weedless, I did an experiment with my nelo 550. Instead of buying a weedless rudder, i bought a second nelo surf rudder and turned it into an epic weedless by cutting it down, building back a new lead edge with thickened epoxy, then sanding to a foil cross section. I’ll attach a pic. I am really happy with it. I could blacken the epoxy and make it look nice but ugly does not bother me. In hindsight it would have been easier to buy the plastic nelo surf rudder and then just shape it without messing with epoxy. 

 

I would just go with what Don recommends, he can build what you need for the same price as an Epic surf rudder. I am planning to do the Carolina Cup with a borrowed gen 1 V8 and he suggested a 9" 20 degree high chord rudder as the gen 1 V8 has the rudder mounted pretty far back. He said a 7-8" could work too, but no real disadvantage to the longer blade with that boat.

You could get a replacement weedless rudder at the same time and not have to mess with the Epic weed guard. The 4" 40 degree I have on my Nelo 550L gen 1 has never had issues with weeds and I use that most of the time, only switching to the 7" 35 degree DK for rougher water.

-- Andrew

I would just go with what Don recommends, he can build what you need for the same price as an Epic surf rudder. I am planning to do the Carolina Cup with a borrowed gen 1 V8 and he suggested a 9" 20 degree high chord rudder as the gen 1 V8 has the rudder mounted pretty far back. He said a 7-8" could work too, but no real disadvantage to the longer blade with that boat.

You could get a replacement weedless rudder at the same time and not have to mess with the Epic weed guard. The 4" 40 degree I have on my Nelo 550L gen 1 has never had issues with weeds and I use that most of the time, only switching to the 7" 35 degree DK for rougher water.

-- Andrew

Great info guys, thanks. 

I literally just applied an epic weed guard on Friday after waiting 3 months for them to come back in stock. Until the race on Sunday I thought weeds were my biggest problem. So If I go with the DK 9" high chord rudder it wont fit with my epic weed guard? That's a bummer. 

Don Keisling will make you anything you want him to, so tell him you have an Epic weed guard and he can construct the rudder to work with it.

-- Andrew

A DK surf rudder with the shaft positioned to mate with the epic weedguard -  I like that Andrew! Sounds like the best of both worlds. 

Regarding rudder angle, different weeds have different requirements. For dense milfoil in the midwest USA a 40 degree angle is not weedless, but a 45 is. Weeds in other places must be more slippery. 

I 2nd the low angle rudder. After going from. DK 20*(?) on my SFS to the stock Kai Waa Vega near vertical rudder, I can say I will only order near perpendicular rudders from now on. The Vega's low angle balanced design is light and responsive.

Go big. high chord. In big stuff you can never have too much rudder. I did a 20* 9" high cord and occasionally wished for more rudder in  3' steep ocean ferry wake or steep 4'+ windswell.
In retrospect, I think the size was adequate but a lower angle of attack and more balanced rudder post position would have been the ticket

After speaking with Don I decided to go with a 9" high chord rudder with a stepped leading edge to match the epic weed guard. The only downside it that it only comes in PC so no carbon "bling" for this rudder. Can't wait to try it out.

I bet you will love that DK surf rudder. They have a cult following for a reason. 

Make sure that weed guard is really well attached to your ski. 3 months is a long wait!

zachhandler wrote:

 i would just get an epic surf rudder. It is a very good rudder and it is designed to mate perfectly with the same epic weedguard that you already have on.

Bottom line - for all my epic skis I have used epic weedless and epic surf, always with the weedguard on, and I love that system.
 

Do you really mean the surf rudder? That's weed catching monster as far as I know... Did you perhaps mean the "rough water weedless" rudder? See www.epickayaks.com/store

I'm trying to decide between that and having DK make something for a V12... Can you say more about "Even more important in regards to performance, i think, is the near vertical lead edge of the epic weedless. It allows crisp and precise turn initiation. Other weedless rudders are very slow to respond if you are actually surfing with them." Why is that?

I recommended an epic surf rudder to complement the epic weedless he already has, assuming he is not surfing in weeds. If he needs his surfing rudder to also be weed free, then there has to be compromises. I have both the epic rough water weedless rudder and a DK huge raked back weedless rudder of similar size. They are for different boats so hard to compare the two directly, but both are imbalanced and have the dead and sluggish feel of an imbalanced rudder. You have to push hard to turn, and the boat does not react that quick. But yes they are weedless, and yes they have more bite and turning power than a standard weedless, so they would be usefull in big weedy situations.  I just dont like the feeling of them, and in the weedy waters I paddled I end up just making due with a standard size weedless rudder. You can compromise of course by picking a rudder angle intermediate between a surf and weedless rudder. It will have somewhat better ability to shake of weeds particularly with the boat tilting downhill and lifting the rudder out of the water periodically. The epic universal rudder is an example of that type. But I nickname that rudder the useless rudder as it is not weedless where I live and is a much worse surf rudder than an elliptical. The fenn sharkfin is another example. Some people must really like those rudders but I think they surf poorly. 

More vertical rudders are said to be more efficient than swept back ones, meaning the ratio of lift to drag they generate is higher. I haven’t taken the time to read up on the physics behind that. And I can’t explain why they make a turn initiate crisply. But the effect is very noticeable when on a wave. 

Thanks for all the input. I'll let you know in a few days how the new rudder performs. Communication with Don at DK rudders is awesome and he'll build whatever you need. I went with his recommendations. I ended up with a 9" 30 degree high chord rudder with a stepped leading edge to match up with the epic weed guard. 

I think we finalized the measurements on Thursday and the new custom built rudder will be at my house on Monday. Crazy fast.

zachhandler wrote:

More vertical rudders are said to be more efficient than swept back ones, meaning the ratio of lift to drag they generate is higher. I haven’t taken the time to read up on the physics behind that. And I can’t explain why they make a turn initiate crisply. But the effect is very noticeable when on a wave. 

The loss of efficiency in swept back rudders or wings is simple geometry. Skipping the physics, you know that high aspect ratio wings (i.e. long and skinny) are more efficient than short fat wings. Now take a straight long skinny wing sticking out from the fuselage at a right angle. An air particle flowing over the wing touches the wing exactly for the distance of its width (chord). Now sweep that same wing back so it's at a 45 degree angle to the fuselage and trace the path of an air particle. It touches the wing for a much longer distance (~1.414x longer) because it goes across it at the 45 degree angle. So in effect, that skinny swept back wing acts kind'a like a fatter stubbier wing (by a factor of 1.414) and fat stubby wings are less efficient than long skinny ones...

WRT to the crisp turn initiation, I wonder how much really has to do with hydrodynamics vs. simply balanced vs unbalanced rudder. With a straight leading edge you (typically) end up with a more or less balanced rudder, so if you're going fast and you push on the pedal the rudder turns easily and quickly. If you have a swept back rudder it's most likely quite imbalanced and thus requires quite some force to turn. When you push the pedal, you have to push harder, the rudder line stretches more, etc. That's bound to feel more mushy.

Any one know the weed conditions for Wrightsville Beach North Carolina? Planning to do the Carolina Cup there in November. Using either my Nelo 550 gen 1 or a borrowed Gen 1 Epic V8 depending on conditions. For the Nelo I have the stock surf rudder or a DK 7" by 35 degree. For the Epic V8 Don Keisling is making me a rudder as the owner only has a 4" Epic weedless right now.

-- Andrew

Andrew,  

when I did the Surf to sound race in wrightsville ( the fall version of the Carolina cup) the waves were 4-6’ and mixed chop. I was on an epic v8pro. Weeds were not a problem. I could have used a bigger rudder then too. All I had was the small epic weedless rudder. 

Got the new DK rudder. Looks great. Can't believe how fast the process was. Hoping to try it out tomorrow. Here's a comparison between the DK and the Epic weedless rudder.

Wow. I think you have the perfect set up now!

Don is such a treasure!

Got a chance to try the new rudder today. Conditions varied from  flat water to 1-2' waves with the occasional 3' tossed in. I paddled my usual 10k course out of the river and into the mouth of the open bay. The rudder tracked like a laser. The wind was blowing across the port bow and the ski felt more "planted". The high chord rudder felt like a centerboard on a sailboat. It increased the stability substantially when going across the wind. Going downwind I was able to change directions on a whim. I think I'll  keep this rudder on and switch out to the epic weedless for the flat water races. The only downside was it still snags weeds even with the epic weed guard. It's a vast improvement over the stock rudder. I'd highly recommend a DK rudder for all your rudder needs.