Paddle - large blade vs. small (theory)

Reading all these discussions about small vs. large blades, I keep wondering why people say small blades allow you higher cadence compared to large blades, thus making it easier on a paddle who can’t wield the larger blade. I don’t buy that - there must be other factors than just the smaller blade area for this to work.



As stated in the other recent threads, they seem to imply that the small blade has slippage through the water compared to the large blade. They even go as far as to say that this slippage is the reason a smaller blade would allow faster cadence (and assuming a faster cadence is desirable).



So how is slippage good for a weaker paddler? I can see that some slippage can help absorb stressful loads to weak joints and tissue. That’s a plus.



But other than that, slippage is just lost energy to turbulence in the water. So, in effect, a weaker paddler using a smaller blade loses additional energy to slippage (that they would not lose with a larger blade with less slippage) in order to maintain higher cadence in a range they would feel comfortable.



That does not make sense to me. Why not maintain the “right” cadence with the “right” size blade that does not slip much in normal use?



If higher cadence is what we are after, then why not use a shorter paddle with the “right” size blade that in most situations will have only minimal slippage?



Slippage is not good for paddling efficiency. Wings, canted stroke with a GP, good catch before the pull - these are all techniques that are aimed at avoiding slippage. So why on earth would one want to introduce slippage by using an undersized blade???



I would think one would want to only go to a blade small enough that would not induce slippage under most uses. Smaller than that is energy wasted to turbulence. Bigger than that is waste too: big blades are heavier and they prevent close catch entry thus loss of paddling efficiency, plus they are more likely to induce an injury in a hard-bracing situation than a smaller blade. But we are talking forward paddling efficiency here.



From my own experience, I started with a mid-wing some years ago, then switched to a small-mid wing based on feedback that the mid-wing was too big for me. I liked it initially but I kept feeling that I can overpower it here and there and it just did not feel nearly as solid in the water as the mid-wing.



Lately I switched to mid-wing again (all same brand). I have shortened my paddle considerably (nearly 5cm). I feel better with the larger blade than I did with the smaller: no slippage and I don’t feel any more stress either. Due to the shorter overall length of the paddle I can maintain a comfortable cadence and I can move my hands a bit closer to the blades thus achieving stronger lever to deal with the larger blade without actually putting more effort into it. My stroke may be a bit shorter now but that also keeps it in the area of most efficientcy too.



To sum it up: I feel one should not downsize to a blade that is so small that it will be subject to slippage through the water in normal use - that just wastes energy. Too big is also bad. Find the “right” size and adjust cadence through paddle length and technique. What do you all say? I’d like to hear logical explanations, not just opinions -:wink:

It’s not the slippage

– Last Updated: Aug-04-11 10:33 AM EST –

I think you are just saying that a blade should be properly matched to the paddler. Gotta say, it starts sounding like you are questioning the experience of those who said that going to a smaller blade helped them go faster.

It's not the water you don't get that's the problem. It's the water that the blade DOES grab which is the issue. If the volume is over-matched for my strength I can't move the blade as fast. I also don't trot along as fast carrying a 50 lb box as a 20 pound one. The former is more than a third of my weight, so of course it takes more bigger, slower muscle to balance it.

At your size it may be difficult to replicate the experience of smaller women - certainly it'd be an expensive experiment to go out and find a really huge blade just to see. But the experience is quite real and a lot of good kayak coaches have seen this make the right difference.

What I question is …

– Last Updated: Aug-04-11 11:21 AM EST –

Statements that sound a lot like what you just wrote (I would not dare question anyone's experience, but I question the reasons given):

"It's not the water you don't get that's the problem. It's the water that the blade DOES grab which is the issue. If the volume is over-matched for my strength I can't move the blade as fast."

My point is that to achieve the above "fast" you seem to imply that the blade slips through the water, thus moving faster than a larger blade would that does not slip.

IMO slippage is bad if it happens in normal forward paddling - you simply lose energy to turbulence. If you want higher cadence, you can do that with a shorter paddle/shorter stroke and you do not need to slip and waste energy to turbulence.

There probably is some golden medim where blade size-paddle length-paddler strenght-slippage-cadence meet. I would not just write a blank check on the smaller blade area alone.

The larger blades being heavier is a separate issue and it needs to be taken into account, but the difference is usually minimal (as little as adding a large watch to your wrist or gloves). Ergonomics of a larger blade getting in the way is more detrimental and smaller paddlers can feel that more than larger ones, I suppose, though if their boat is sized for them it should be less of a difference.

cadence not thru paddle length
As Celia says it’s not quite correct to say the smaller blade has more slippage which I will define as a sort of accidental spilling of the water from the blade causing it to slice and not pull much. Clearly if you had a blade three feet wide it would pull more water but you’d be pulling hard with both arms to move it at all so there is a limit. Clearly how quickly you can move the paddle through the water is related to blade size. So by tuning the blade size to the strength of the paddler and the most efficient cadence you get better efficiency (i.e. faster over a long haul).



A larger paddle blade is really no different than a larger gear on a bike and you choose the gear on the bike based on which will keep a good cadence for the given hill and rider strength.



Yes the paddle length can affect cadence, but it affects other things too which is why I say it’s better to adjust cadence using a well chosen blade size. The paddle length has a big impact on practical stroke angles and many find a higher angle better for efficiency and many find a lower angle better for overall comfort (your mileage may vary).

So it comes back to slippage -:wink:

– Last Updated: Aug-04-11 11:30 AM EST –

You say "Clearly how quickly you can move the paddle through the water is related to blade size." How so? The only way one blade will move "quicker through the water" than another is if it slips or slices. For slicing, size does not matter. So the only thing left appears to be slippage. And we all know slippage is not good in terms of efficiently using power to move the boat.

I'm going to leave aside the argument whether the paddle pulls through the water or one pulls forward off the paddle that stays mostly stationary in the water -;)

Now, if you say that the benefit of increased cadence is more than the loss due to slippage, I can buy that. Especially if there is no better way to increase cadence to an optimal level.

I understand that shorter length has implications. See my reply to Ceila above about the "golden medium".

Slippage
is kind of a misnomer, really. Think more in terms of a wing paddle, where “slipping” actually generates more power.



As a GP’er, I cant my blades to “slip” through the water deliberately - it generates more power than pulling it at a 90 degree angle straight back. It’s the same principle as a propeller or fan blade. You can also use wing paddle technique with a GP, and it really does add power, especially in a sprint.



Personally, I find that big blades are overkill (For me at least), and do more harm to my shoulders than they’re worth. Even my EP’s are narrow blades, and I have no problem keeping up with just about anyone with them or with my GP’s. Higher cadence and a lighter touch make up for any deficit in per stroke torque, and keep my arthritic shoulders in the best shape I can. No pain, and long distances are no biggie.



YMMV, obviously, but I’d never use a big shovel of a paddle - no benefit, and only drawbacks for me.


all blades have slippage
Regardless of the blade size there is water turbulence and slippage of a sort at the edges. But the meat of the blade effectively pulls a certain amount of water. Likewise on a bike in a low gear there is more chain friction in the lower gears. But still you need to find the right cadence and paddle length isn’t a good way to do that so I only see blade size as the controllable option. Without good cadence the extra pull of the larger blade won’t help just due to the nature of human muscles and how they work and recover.

slippage
Wouldn’t slippage be a function of design of the blade not size? My wing does feel like it slips at all unless I let it. I agree that the right blade is the right blade. For me it just depends what I am doing. The shorter I paddle the bigger the blade can be. But if you are doing a 100 miles then smaller is better. Speed is a measure of distance over time. So the less tired I am the faster I can paddle the whole time. In terms of paddling my boat as fast as I can then a large paddle would be better.



I had a similar experience with blade sizing. I found that if I go too small I am just overpowering the blade regardless of how easy I want to paddle.



This question is hard to answer for new paddlers because without experience it is tough to predict what will work. With boats we can all sort of adapt. But the paddle is a very personal experience.



Really the paddle blade size seems to come down to the efficiency argument or the tortoise and the heir.



Ryan L.

I like that !

– Last Updated: Aug-04-11 12:20 PM EST –

"Really the paddle blade size seems to come down to the efficiency argument or the tortoise and the heir."

"Right size for the job" is key.

As for what I call "slippage" (which is pure loss or energy to turbulence) it is clear we are not talking slicing/wing action (which is usually beneficial if done properly with the right paddle).

It is not a question of "gearing" - that is almost obvious that one needs to be in the right gear. The question is how do we get to the right gear? Another analogy - do we raise the engine RPM through slippage in the transmission (as is the case a lot of the time in low-grade automatic transmissions, which transform that slippage to heat, basically) or do we select the "perfect" gear in a manual or continuously variable transmission with absolutely no slippage (which uses all the engine's energy, save for the inevitable friction losses)?

The argument that a smaller blade moves faster through the water can *only* be explained that it just does not grab enough water to couteract the paddler's edfforts. Any movement through the water means displacing water and pusing it aside, then it moves back where it came from - this is something that purely wastes energy and most blade designs and paddling technique I know off strive to minimize this effect. My point is that if one goes too small it will actually be detrimental - I have a very narrow bladed Aleutian paddle that is great (better than any other paddle I have) if I lilly-dip or lend it to someone else who does; but as soon as I try to move at a bit of a training pace, that paddle falls way short in terms of what it can do - it is like paddling with a toothpick, relatively speaking - yes, I can have a fast cadence, but I can't maintain speed and am actually more tired at the end. So, blindly saying get a smaller blade does not make much sense if all we back that with is because "it moves faster throuhg the water"...

Blade size
(Opinion) :Blade size is just one factor that plays a factor in cadence. I agree that shaft length (not paddle length) as Kocho states also plays a role.

(Fact) When switching to a smaller blade with same length of shaft, I am faster, my cadence is higher, and am less fatigued over the same distance. I don’t have a slip-free paddle stroke , not sure if any paddler does. So to Kocho ,How would you explain my results with a smaller blade?

Where the issue lies

– Last Updated: Aug-04-11 12:23 PM EST –

If people getting too small a blade was a large problem, we'd be talking about this from the other side. I suppose it would be possible to get to such a small blade that the cadence required was uncomfortably fast for a given paddler.

But that's not the usual issue. The more typical problem is that people get a huge honking blade, or advise their spouse to do so, thinking that the smaller a person is the bigger a blade they need to keep up. A few trips to the nice shoulder doc later, they ask for other advice.

Boat volume can't bail out a mismatched paddle blade. One of my boats is decently sized for me in volume and the other has too much volume. The unneeded size of the Epic Active Tour is an equal issue in both. BTW, it doesn't get any more comparable. Weight is within a few ounces and I had a new ferrule put on the Epic (Active Tour) so it can be set to the same length as the Werner. I often switch to the Active Tour if we are letting others try our paddles, since I am usually the only one with paddles sized for a small paddler. My paddles go out on loan a good bit.

Shorter strokes help, but the exertion during the stroke is still noticeably more challenging. The only thing I get with shorter strokes to reduce the length of the exposure over a trip.

The water that is not helping me go forward is not very important compared to the water that is helping. So the science theory is interesting, but not nearly as important as paddling more easily and effectively in terms of distance versus energy expended.

To “Fact”
"(Fact) When switching to a smaller blade with same length of shaft, I am faster, my cadence is higher, and am less fatigued over the same distance. I don’t have a slip-free paddle stroke , not sure if any paddler does. So to Kocho ,How would you explain my results with a smaller blade?"



I assume your higher cadence is more optimal for you and the effect of it overcomes what I believe is loss due to slippage. As said earlier in the thread…



Second factor, may be more important, is that the smaller blades usually allow a better catch with more rotation. Thus increased efficiency in the most important part of the stroke.



For non-feathered paddles - windage is also a factor that improves with smaller blades.



All of the above can explain your results. I would also guess you have improved over time (unless you actually clocked yourself repeatedly on somewhat controlled courses with 2 different paddles).

agree
I didn’t catch the notion earlier of blindly going smaller (and maybe yet smaller). Yes, just as too big a blade is not good too small isn’t either. Just as a ultra low gear on a bike is no good. So you pick the biggest blade that can be paddled at a good cadence for your distance (a body mechanics question that varies a bit from person to person).



The point many were making when advocating a smaller blade was that what seems good for short, sprint type work where you like a real good bite may not work as well over the long haul because too much effort or too low of a cadence will fatigue muscles quickly. So you don’t want to then go overboard and use too small a blade, but you may want to dial it down a bit from what may feel right for short bursts. Also, sometimes one gets used to the feel of a larger blade and is actually in too high of a gear. They try a slightly smaller blade and it may often feel like it slips too much but only because they have to adapt to that more efficient cadence. Again I’m only talking about small changes that are needed to get the cadence right and not blindly going smaller.



Still the blade size is your gearing for lack of any other control and paddle length isn’t right for that control.

I can buy that
Yes the higher rate may make up for slippage but wouldn’t more strokes equal more slippage overall.

Yes as the season moves along I get more fit but I’m also basing my results compared to by training partner. With the larger blades I was slower overall vrs my partner , smaller blades ,consistently keep up.

Easier over long distances
I’ve often thought one of the factors in the easier over long distances thing is determined by kayak efficiency. The further you push with each stroke into that more inefficient area, the more accelerating and slowing occurs between strokes, which I suppose just all adds into the same overall lower efficiency. So I use a smaller paddle that slips, or becomes overpowered, preventing me from reaching that higher level of inefficiency. My cadence increases because I’m still trying, but the pounds of pressure don’t peak as high.

Perhaps there could be some overlap in there where a little less force, but a more consistent speed held,and maybe even more evenly applied force, results in a higher overall speed?

If that’s the case, I would think that the blade that allows the cadence without slipping would be the best. But a different kayak efficiency, a different current, different windspeed, etc? You might be able to hit it right on once in a while, but any change, and you’re no longer there.

I guess that’s why I use my biggest blades with my fastest boats, where I can work up to a comfortable cadence with them without feeling that wall.


Forget slippage
All paddles have slippage, because they operate in a fluid environment. In fact, that’s the working definition: “a fluid is a substance that deforms continuously under an applied shear force”. The shear force is the force you apply to the paddle shaft, and the blade transfers it to the water in the form of a shear force.



A small paddle will require less force to draw through the water than a geometrically similar larger paddle, due to its lesser surface area. The force will also depends on the relative velocity (squared) with which it is drawn through the water.



Power application is the product of applied force times the velocity of the paddle. Any paddler will have a given continuous power output that is comfortable. Therefore if I use a smaller blade (which requires a lesser force to move for a given velocity), I will be able to move it through the water faster for a given power level.



The other primary consideration is the paddle force itself. If you’re using a paddle that’s too big, you will have to slow it down. If it feels too slow, you will be tempted to speed it up, possibly increasing the paddle force to a level your shoulders, elbows or wrists can’t withstand, resulting in injury. As paddle force is proportional to velocity squared, the force can get big in a hurry, and a quick sprint to get out of a touchy situation may cause an injury.



In my mind there is a complex interaction between paddle blade size, cadence (i.e. paddle blade velocity) and applied force that has to be optimized by each paddler. The boat matters too, obviously. I try to use the smallest blade possible that gives a relaxed cadence and a cruising speed I’m happy with. Other more gung-ho types would be very unsatisfied with my setup. I think the personal preferences of individual paddlers gets in the way of making any valid blanket statements about blade size, cadence and so on.

This makes the most sense to me
so far - that is exactly what I was trying to convey, for the most part. Thanks!

Bigger should be better
I have been pondering the same thing for a while.

This article explains how a paddle works better than an other that I have found.



http://www.guillemot-kayaks.com/guillemot/information/kayak_design/how_a_paddle_works



A wing blade is slightly different then a normal one because you are moving the blade sideways and acting on a larger volume of water. This means the water going backwards is moving slower and therefore less energy is lost in moving it. This is why a wing blade is more efficient. Most explanations for how a wing works, don’t address the underlying principle that the wing is moving air downward. This site shows it in a simplified way.

http://www.grc.nasa.gov/WWW/K-12/airplane/newton3.html



The physics shows that a bigger blade should be more efficient, but there must be something in human physiology that makes a smaller blade better.

add this
With a drag paddle you can not propel your kayak faster than your movement - if you draw your paddle with velocity V, your kayak can not go faster than V. Due to energy dissipation it will, actually, go a bit slower.



As you pointed out - less surface area, less force. To apply the same force one would need to move smaller paddle faster. The speed of that paddle movement is limited by the paddler. If, theoretically, the same paddle movement speed could be maintained by a paddler, larger force would be applied with the larger paddle, which implies higher top speed.



The cruising - different strokes for different folks. Watch joggers to fully appreciate that. World class runners have very leisurely cadence, long strides. Everyday folks have short strides and high cadence. Difference - training and technique. Well, probably weight differences as well. I notice that my running stride and cadence change if I carry significant weight.



ignoring for the moment the inefficiency of turbulence near the edge of the blade I think that you will move a kayak just as well if you move X amount of water Y times per minute as moving X*2 water Y/2 times per minute. But most engines and definitely humans have a preferred RPM that is most efficient FOR THE MOTOR. To Kocho’s point going smaller isn’t automatically better as much as finding the right size to hit the right cadence is important, but for may people that just happens to be smaller than they might think at first.



fyi, by far the biggest fault of new cyclist is using too high a gear for any given conditions. It just seems to feel more powerful if you’re really feeling the effort, but that backfires on long hauls.



btw, I love my bigger blade for surf (need to get power with just one or two strokes) and for long downwind runs (like going downhill on a bike).