Rainy Day Feather-Angle Experiment and More

[subaruguru]

Although I didn't enter into a detailed discussion with the folks at CRCK, I found it interesting that they're now buying fixed UN-feathered paddles for their rental use. They offered that it simply eliminates the need to explain or ask novices to develop a "control" hand. Interesting. I'm so locked into a 60 deg feather that I find it difficult to dial back below about 40. Unfeathered feels completely unnatural. Using a bent shaft to protect my small wrists perhaps compounds this intransigence....

[leong]

Leon,

You and I are actually using the same definition of "control hand", i.e., one hand that controls the paddle blade angle at all times, typically the paddler's dominant hand.

Jason tried to explain my "no control hand" technique in a different way, that the hand nearest the water controls the angle of the blade and it alternates back and forth on every stroke. He's probably found, as I have, that some people find it easier to visualize having alternating control hands than no control hand. It's two ways of looking at the same concept. Tomato, tomawto, so to speak.

As for your question about feather angle and stroke angle, I'm not sure how to interpret the recommendation, but my suggestion would be to use whatever paddle angle lines up the blade properly with the water for the stroke angle you use. I strongly suspect that there's too much individual variation in physique, flexibility and technique for someone to say that you must use a certain feather angle with a particular stroke angle. While matching the two angles in question may work perfectly for the person suggesting it and it may be a good starting point, that doesn't mean it will work for you. If you've found that a 52 degree feather works best with your technique and equipment, that's all that matters. There's certainly no reason that you can't experiment to see if perhaps something different would work better, but I wouldn't stress over the fact that you're doing something different from another paddler, no matter how accomplished they may be. Unless they can produce a study of a statistically significant number of paddlers that shows that matching the angles is always the most efficient setup, I would treat the recommendation and just that, a recommendation. Assuming a high level of competence in technique, real-world experience with one's own body and gear trumps generic recommendations every time, IMO.

Thanks, Brian. I agree with everything you said here. Previously, I was afraid that this thread was degenerating into an argument about nomenclature that’s of minor importance to me, as long as everyone knows what everyone means.

Today I was out paddling with two friends; I had a chance to retry my basement experiment with more realistic conditions on Salem Bay. It looks like the high angle paddling style I use and the 52-degree feather angle is just about right to reset my off-side paddle squarely for the catch (with absolutely no wrist action). But you’re right, it varies from person to person. For example, my trusty partner uses a smaller feather angle (only a 35-degrees) with the same high angle paddling style; however, her off-side paddle lands just as squarely as mine does.

Leon

[ThomasL]

Greg Barton says,

“On the first feathered paddles, the blades were offset at 90 degrees. This provides the most efficiency for the returning blade. However, using a full 90-degree feather requires a large amount of wrist action, and many paddlers were unable to twist the paddle enough to give a square pull on the water on both sides of the stroke. Therefore, paddlers began feathering their paddles at angles less than 90 degrees. Today virtually nobody uses a full 90-degree feather — most use 80 degrees or less.”

So, according to this the advantage of feathering is to reduce wind resistance, but apparently at the cost of more flexure at the control wrist. I think that there is a second disadvantage to feathering a paddle. The greater the feather angle the harder it is to do off-side braces and rolls.

Since it rained most of today I went down to my basement (paddle in hand) to do an experiment (I use a 52 degree feather angle with my wing … don’t ask, I’m just used to it). I reset my paddle to the unfeathered position. Then I simulated a paddle stroke with the unfeathered paddle. I held my right wrist straight while my right paddle was out far for the spear and catch in the pretend water. (Note to the reader: Don't try this at home … I almost destroyed a $400 carbon fiber paddle). When I brought my right arm up so that I could do the catch with the left blade, I noticed that my left wrist had to be flexed somewhat to make the left blade square with the water. So, in effect, just paddling automatically rotates the paddle as you alternately bring up one arm and then the other. So, at least for me, it looks like it’s not true that unfeathered paddles don’t require any wrist flexure. Perhaps there is some optimal feather angle that minimizes or reduces the necessary wrist flexure. And, perhaps that ‘optimal” angle is the best feather angle that one should use. Of course that “optimal” angle for reducing wrist flexure will not be optimal for reducing wind drag on the paddle.

It appears that the “optimal” angle is strongly dependent on the paddling angle; i.e., how upright you hold the paddle during each stroke. Perhaps there is a simple relationship between the optimal feather angle and the angle between the top arm and the bottom arm at the catch.

Anyone want to solve this problem? I heard that people in Oslo are considering a new Medal for the Prize in Sea Kayaking (I have Norwegian friends there). Obviously, this prize would have no foundation in Nobel's will, and would not be paid by his money (i.e., it would technically not be a Nobel Prize and the present Nobel family would not accept it as such). However, like the Medal for the Prize in Economics, it would be awarded together with the other Nobel prizes.

PS

While researching for this topic (with no results) I did find something interesting that seems to contradict the concept of the pause to glide. Here http://www.roguepaddler.com/tweak.htm it says,

“Your paddle stroke should be one, continuous, fluid motion, not unlike the movement of legs pedaling a bicycle. As one paddle blade is getting ready to exit the water (just as it pulls past your hip at the end of your stroke), the opposite paddle blade should already be extended far forward, ready to enter the water and begin the next stroke.”

Dr. Binks, did you ghost write this?

Hmm, there are lots of contradictory opinions out there in the so-called world of the “experts”.

MMMM!

I'm going out tomorrow. Most of my old paddles only allow for the 90 degree setting, but most of the new allow for infinite adjustment. Recent(within the last 5 years) experience has shown me that the optimal degree of feather is dependent on the velocity of the wind encountered and at how one's course dictates it is to be dealt with. For a simple day tourer like myself the rule of thumb 60 degree(or is that 30?LOL) setting works best in most conditions. Tomorrow, between Cliff bars and hydration, I will attempt to determine if incremental adjustments of "feather angle" make my tour more efficient.

Tom

[djlewis]

Paddling straight into a headwind is not great , (the paddle acts as a sail)...

And when paddling with a tail wind, it's a propeller, right?!

Actually, neither, on average.

The push forward of the dry blade generates, on average, only as much backward propulsion as it would in still air. (See prior mathematical model, of which this is a non-technical summary.) So while the dry blade sail effect may seem uncomfortable in a high head wind, it's actually not any worse for drag, on balance.

Of course, that discomfort is a potential problem of a different sort. But if you're worried about a dry blade being buffeted by wind apart from blade motion, then feathering is again irrelevant, on average, because the wind can come equally likely from any direction.

Unless, of course, Peter, you are one of those lucky paddlers who always have a head wind. But then you have bigger problems than just your paddle in the air, dontcha. You need to get a storm paddle! And remind me to do circuits the opposite direction from you, when possible.

[leong]

And when paddling with a tail wind, it's a propeller, right?!

Actually, neither, on average.

The push forward of the dry blade generates, on average, only as much backward propulsion as it would in still air. (See prior mathematical model, of which this is a non-technical summary.) So while the dry blade sail effect may seem uncomfortable in a high head wind, it's actually not any worse for drag, on balance.

Of course, that discomfort is a potential problem of a different sort. But if you're worried about a dry blade being buffeted by wind apart from blade motion, then feathering is again irrelevant, on average, because the wind can come equally likely from any direction.

Unless, of course, Peter, you are one of those lucky paddlers who always have a head wind. But then you have bigger problems than just your paddle in the air, dontcha. You need to get a storm paddle! And remind me to do circuits the opposite direction from you, when possible.

David,

It’s interesting; feather angles from 0 to 90 degrees sure are a controversial subject, here and elsewhere. Some here in NSPN think the only advantage of a non-zero feather angle is a reduction of air resistance at the cost of less efficient biomechanics. Others, like you (I think), state the advantage is more efficient biomechanics and a trivial reduction of air resistance on average. Personally, I think the advantage is improved biomechancis as well as some decent reduction in air resistance (even with no wind). Strangely, I don’t agree with everything one of my heroes (Greg Barton) says. Here he says http://www.epickayaks.com/extras/tips/equipment/feather-angle,

“Unfeathered paddles do not require wrist rotation and put less strain on the wrist.”

For me, the proper non-zero feather angle allows paddling without any rotation of the shaft in the control hand as it rotates in the loose hand on the wet side. Also, for me, a non- feathered blade requires me to do the “motor cycle thing”; i.e. twist the wrist up and down in each paddle stroke. I’ll have to watch Ben Lawry paddle again to see how he handles a non-feathered paddle; however, when I raced him in last year’s Nahant Bay race I’m pretty sure that he was using a feathered wing paddle.

As I’ve said elsewhere in this thread, the resistance of a non-feathered paddle in still air (at the top of the stroke) adds about 2.7% to the kayak’s drag. Actually, more since my “back of the envelope” model of air resistance is more conservative than results that I’ve since seen published. For recreational paddling, 2 or 3% seems trivial. But in racing it’s not trivial at all. Otherwise, elite paddlers wouldn’t bother with a wing paddle because it only improves their speed by about 2%, at the cost of using a heavier paddle.

Surfski.info did a poll of its readers asking what feather angle they use (also paddle length). See http://www.surfski.info/getting-started/tips-other/item/1270-what-feather-angle-do-you-use?-greg-barton-on-wing-paddles.html for the report. I’m pretty sure that that the readers of surfski.info are fairly competent racing paddlers. Here is my summary of the results for feather angle (rounded to the nearest 1 %):

No feather – 1%

45 degrees – 15%

60 degrees – 21%

67 degrees – 30%

75 degrees – 4%

Don’t know – 15%

I think that you can assume that the “don’t knows’ use feathered paddles. I left out the smaller percentages (like 37 degrees - 0.16%) so it seems like all but about 1% of surfski.info paddler’s use feathered paddles.

As Brian said elsewhere in this thread (and I couldn’t agree more), “my suggestion would be to use whatever paddle angle lines up the blade properly with the water for the stroke angle you use. I strongly suspect that there's too much individual variation in physique, flexibility and technique for someone to say that you must use a certain feather angle with a particular stroke angle.”

Respectfully,

Leon (who’s enjoying the cold water now in NE)

[djlewis]

David,

It’s interesting; feather angles from 0 to 90 degrees sure are a controversial subject, here and elsewhere. Some here in NSPN think the only advantage of a non-zero feather angle is a reduction of air resistance at the cost of less efficient biomechanics. Others, like you (I think), state the advantage is more efficient biomechanics and a trivial reduction of air resistance on average. Personally, I think the advantage is improved biomechancis as well as some decent reduction in air resistance (even with no wind).

Good summary of my position. I think evidence of the size of the air resistance effect is how much propulsion you can get by waving a paddle around in the air! Have you tried it?

I’ll have to watch Ben Lawry paddle again to see how he handles a non-feathered paddle; however, when I raced him in last year’s Nahant Bay race I’m pretty sure that he was using a feathered wing paddle.

Who won?

As I’ve said elsewhere in this thread, the resistance of a non-feathered paddle in still air (at the top of the stroke) adds about 2.7% to the kayak’s drag.

Sound high to me. But even if it's that high or higher, bear in mind that the maximum resistance only occurs for a small part of a stroke cycle. Even integrating (averaging, for non-geeks) over a whole cycle seems likely to be under 10-20% of that, so we are talking tenths of a %. Any biomechanical effects are worth far far more than that, so they wash out air issues, which still feel like a non-factor for racers and general efficiency.

As for recreational paddlers in high wind, I'll say again -- carrying a storm paddle will do far more to eliminate wind-on-paddle issues -- that's what it's for and why it's named that. 'Course you gotta learn how to use a storm paddle, with a sliding stroke etc, but it's kinda neat, IMHO (not that I am an expert).

[leong]

Good summary of my position. I think evidence of the size of the air resistance effect is how much propulsion you can get by waving a paddle around in the air! Have you tried it?

Who won?

Sound high to me. But even if it's that high or higher, bear in mind that the maximum resistance only occurs for a small part of a stroke cycle. Even integrating (averaging, for non-geeks) over a whole cycle seems likely to be under 10-20% of that, so we are talking tenths of a %. Any biomechanical effects are worth far far more than that, so they wash out air issues, which still feel like a non-factor for racers and general efficiency.

As for recreational paddlers in high wind, I'll say again -- carrying a storm paddle will do far more to eliminate wind-on-paddle issues -- that's what it's for and why it's named that. 'Course you gotta learn how to use a storm paddle, with a sliding stroke etc, but it's kinda neat, IMHO (not that I am an expert).

>>”Good summary of my position. I think evidence of the size of the air resistance effect is how much propulsion you can get by waving a paddle around in the air! Have you tried it?”

No, but it’s obviously going to be very small. But I do hold up my paddle in a strong wind (say 20-mph) and it does act like a small sail. I’d guess it propels you at about 0.5 to 1.0 mph. When your paddling 6 mph in still air the paddle hits a maximum speed with respect to the ground of about 13 mph (boat speed = 6 + paddle speed = 7).

>>Who <between Ben and Leon> won?

Two prizes: I won for kayaks and Ben won for surfskis. See the picture I just dug up.

As I’ve said elsewhere in this thread, the resistance of a non-feathered paddle in still air (at the top of the stroke) adds about 2.7% to the kayak’s drag.

>>”Sound high to me. But even if it's that high or higher, bear in mind that the maximum resistance only occurs for a small part of a stroke cycle. Even integrating (averaging, for non-geeks) over a whole cycle seems likely to be under 10-20% of that, so we are talking tenths of a %. Any biomechanical effects are worth far far more than that, so they wash out air issues, which still feel like a non-factor for racers and general efficiency.”

Well, it’s a win-win situation; both biomechanical improvement and air drag reduction. Without using my own Mathcad model for this exercise (in case I made a mistake … yeah, even I make mistakes) just use the table on page 95 of the kayak navigation book that I referenced earlier in this thread. It has a curve of wind force versus speed for 2 square feet of flat surface perpendicular to the wind. Reading the graph, for a speed of 12 knots the wind force is about 1.5 pounds. That’s at least twice as big a surface area as a kayak paddle. But to be conservative, assume a kayak paddle has an area of 2/3 square feet. So, a 12-knot wind will push the paddle with a force of about 0.5 pounds. Yes, of course, that’s the peak force as the paddle cycles around. Nevertheless, I don’t think that force is trivial even if it’s just part of the time.

Peace my friend. Let’s go paddling instead.

Leon

[djlewis]

Peace my friend. Let’s go paddling instead.

Leon

I agree -- too many mistakes and questionable reasonings in your last post to make any more discussion worthwhile. ;-)))

See ya on the water-- we'll do some more experiments.

--David

[leong]

I agree -- too many mistakes and questionable reasonings in your last post to make any more discussion worthwhile. ;-)))

See ya on the water-- we'll do some more experiments.

--David

Come on David, I didn’t want to continue this but you forced me to do it. In my last post I don’t think that I challenged any of your prior math or reasoning. I didn’t say anything really new. I agreed with you that the biomechanical efficiency part was more important than the wind resistance part. It’s not my fault that Olympic racers and their coaches consider both important. All I did new was to use a published result to quantify the force of the wind; I also answered your question about who won the Nahant Bay race. I don’t know what’s your problem?

I guess like Nixon, you have a secret plan to challenge the many “mistakes” and “questionable” reasoning of my last post. When did you enroll in the school for scoundrels? Your last word should have been something like “yeah, let’s go paddling” and that would have been sufficient. Instead, for all to see, you gave an unsupported statement that I made many mistakes and that my reasoning was incorrect. I know you really didn’t mean it that way.

Peace, anyway. Let’s go paddling.

Leon

[djlewis]

Yes, Peace!

[leong]

I thought it might be of general interest to add what Jen Gleck says about feathering. She’s America’s first BCU Level 5 Sea Kayak Coach (I’ve rented kayaks from her at her at Aqua Adventures business in San Diego). Here are her words (I think consistent with what some of us have been saying):

It might be an interesting exercise to consider that whitewater boaters certainly have the most reliable off-side rolls in general. Whitewater boaters paddle feathered (w/very few exceptions). They also have very reliable braces on both sides. If we're talking about reliable skills in kayaking, I think the bigger issue than feathered or unfeathered is practice and use of the techniques. THAT is what makes skills dependable, not the equipment. Whitewater boaters need to brace and roll every time they paddle. Many sea kayakers actively avoid conditions in which they might have to brace or roll. These skills go unpracticed and it doesn't matter what paddle you use! The key is repetition until bracing/rolling becomes part of muscle memory and becomes instinctive. For this to work, you must be committed to a "control hand" that does not shift position. As long as your control hand is stationary on the shaft, your body will learn exactly how to move so that the blade is flat for braces and rolls - but only with repetition! In addition, during all this practice, you will develop a feel for pressure on the paddle blade and your body will begin to figure out how to rotate the blade until the desired pressure is achieved - all without thinking about it.

I always paddle right control feathered, but I go from 60 to 45 degrees pretty easily and bigger differences without much more effort. My first few strokes upon switching from one to the other usually involve a bit of slicing, especially if I'm playing kayak polo where I need to be quick and am bracing a lot. This vanishes within minutes and the only conscious thought that goes through my brain is "oops" as I slice. My body automatically corrects its movements until I don't slice anymore. Sculling draw, sculling brace, bow rudders, and hanging draws can all help you develop the feel for the blade in the water and to train your muscles how to move to change the pressure on the blade. When you can perform a steady bow rudder, effortless hanging draw, or solid low brace all on flatwater and all without looking at your blade, your rough water skills and your adaptability to different equipment will also be strong!

On the other hand, the right equipment can go a long way towards promoting good technique (though it can never replace practice). That's why at Aqua Adventures we use and teach with feathered paddles because we feel it promotes the most efficient paddling style - hands at eye level, lots of torso rotation, short stroke from toe to hip blade close to the boat. We also promote shorter paddles for the same reason - 220cm max and 215 for many.

[Deb Millar]

Not to put too fine a point on it, but Jen's last name is KLECK.

Just in case anyone wants to look her up.

Deb

[leong]

Not to put too fine a point on it, but Jen's last name is KLECK.

Just in case anyone wants to look her up.

Deb

Oh, that's why she slapped me last time. No, seriously, it was a typo. Thanks for pointing that out.

Leon

[djlewis]

I thought it might be of general interest to add what Jen Kleck [corrected] says about feathering. She’s America’s first BCU Level 5 Sea Kayak Coach (I’ve rented kayaks from her at her at Aqua Adventures business in San Diego).

Yes, Jen Kleck -- a wonderful coach and person. She set Deborah and me up with some great paddling and equipment for two days in San Diego... and personally ferried us to La Jolla so we could make a one-way trip back to San Diego. At some symposia long ago, she has more than once helped me boost my paddling to higher levels.

What she says about feathering -- and rolling -- is interesting, and reflects my own experience, though certainly at a lower level of performance. When I change feather angle, my stroke too almost automatically and unconsciously corrects itself within a few cycles. As for rolling, in the days when I paddled much more and practiced rolling more as well, I had a lovely, reliable, thought-free roll in most any boat. Now that I paddle less and have become one of those kayakers who "avoid conditions in which they might have to brace or roll", my roll and brace have gone to heck, which, of course, leads to more avoidance and more deterioration.

[Brian Nystrom]

I thought it might be of general interest to add what Jen Gleck says about feathering. She’s America’s first BCU Level 5 Sea Kayak Coach (I’ve rented kayaks from her at her at Aqua Adventures business in San Diego). Here are her words (I think consistent with what some of us have been saying):

It might be an interesting exercise to consider that whitewater boaters certainly have the most reliable off-side rolls in general. Whitewater boaters paddle feathered (w/very few exceptions). They also have very reliable braces on both sides. If we're talking about reliable skills in kayaking, I think the bigger issue than feathered or unfeathered is practice and use of the techniques. THAT is what makes skills dependable, not the equipment. Whitewater boaters need to brace and roll every time they paddle. Many sea kayakers actively avoid conditions in which they might have to brace or roll. These skills go unpracticed and it doesn't matter what paddle you use! The key is repetition until bracing/rolling becomes part of muscle memory and becomes instinctive.

This is absolutely true; there is no substitute for practicing and using skills.

For this to work, you must be committed to a "control hand" that does not shift position.

Unfortunately, this is complete nonsense if you're paddling unfeathered. Like many people who paddle feathered, she apparently doesn't get the fact that if you paddle unfeathered, you don't need a control hand.

As long as your control hand is stationary on the shaft, your body will learn exactly how to move so that the blade is flat for braces and rolls - but only with repetition! In addition, during all this practice, you will develop a feel for pressure on the paddle blade and your body will begin to figure out how to rotate the blade until the desired pressure is achieved - all without thinking about it.

However, when applied to a feathered paddle, it does make sense.

On the other hand, the right equipment can go a long way towards promoting good technique (though it can never replace practice). That's why at Aqua Adventures we use and teach with feathered paddles because we feel it promotes the most efficient paddling style - hands at eye level, lots of torso rotation, short stroke from toe to hip blade close to the boat.

Again, she apparently doesn't understand that you can do the exact same things with an unfeathered paddle. There is nothing magic about a feathered paddle that improves one's technique. If they try to force everyone into the same paddling style - which is what the quote implies - I think it's unfortunate, as that simply doesn't work. Any good coach knows that.

[billvoss]

For this to work, you must be committed to a "control hand" that does not shift position.

The above is the only part I disagree with. Though just like picking one roll on one side, picking one hand in one position would probably make learning easier at first.

In addition, during all this practice, you will develop a feel for pressure on the paddle blade and your body will begin to figure out how to rotate the blade until the desired pressure is achieved - all without thinking about it.

Exactly.

[leong]

Not to guild the Lilly, here's an interesting discussion about feather angle http://www.surfski.info/forum/1-general/4820-is-feather-really-required.html

Feel free to argue with them, not with me. I’m agnostic on this subject; however, a 52-degree feather angle seems to work best for me.

Leon

[subaruguru]

Hey Leon,

I hesitate to simply question your semantic, or maybe spelling error re: "gild the lily", but now wonder if maybe you were right, as this was before my time:

http://www.youtube.com/watch?v=PE-kn9pIK88

See ya soon.

Ern

[leong]

Hey Leon,

I hesitate to simply question your semantic, or maybe spelling error re: "gild the lily", but now wonder if maybe you were right, as this was before my time:

See ya soon.

Ern

Ern,

I graduated HS with Bill Shakespeare and joined his guild so I got used to this spelling.

Leon

[Gcosloy]

Shakespeare as far as I know never joined the union (guild).

Shakespeare didn't coin the term 'gild the lily', but he came as close to doing so in King John, 1595:

SALISBURY:

Therefore, to be possess'd with double pomp,

To guard a title that was rich before,

To gild refined gold, to paint the lily,

To throw a perfume on the violet,

To smooth the ice, or add another hue

Unto the rainbow, or with taper-light

To seek the beauteous eye of heaven to garnish,

Is wasteful and ridiculous excess.