Were They Using “Goon” Strokes?
Impossible for me to switch sides stroking them things, for every time I do, I fall over. So I paddle only on one side using a “pitched” stroke.
Length + width + shape
Seems to me that even if they are designed to be planing hulls, they won’t behave that way unless they are surfing, or being towed.
So, at the end of the day, the same laws us canoeists have to live with apply to the SUP paddlers. Having a poor length to width ratio will make for a slower craft.
Put another way, if the total displacement is 100l, a craft that could displace that over 17’ with a 25" waterline width would be easier to paddle than one that was 12’ long and 31" wide. It seems to me that SUPs would need to be wider than canoes, or else less stable, given that the paddlers COG would be higher.
I’d bet on the canoe.
Kayak Comparison
I recently bought a 14’ x 28" SUP shown here on flat water.
http://www.youtube.com/watch?v=4oN8GtBh0sU
I didn’t have a chance before the winter to develop a good stroke but it seems about 1/2 to 3/4 mph slower than my Tempest 165 of the same waterline length, maybe like a flat-bottom canoe. Even with a low-rocker displacement bow, it’s still an open-water board, and I’ve had it in 2-3 foot wind waves. Balance is a challenge at first, but you get much better every time out.
There are also flat-water race SUPs of 25"-27" wide that are faster, but not all-around boards. You see a lot of SUPs with planing bows with high rocker since their origins are from surfboards, but as a kayaker, I’d definitely recommend starting with a narrower displacement bow SUP unless you just want to surf.
The “downwinder” videos show SUPs where they are the most fun. The rear half of any board is basically a surfboard, and you can move about on the board to help catch and ride waves.
http://www.youtube.com/watch?v=hasoYNd7Zog
racing sup
I had the pleasure of getting shown the Yolo board shop down in Santa Rosa Beach, Florida. They had a experimental or custom 18’ SUP with a kick tiller so one could paddle on one side for a while and help negate the wind. It was cool. However they did say it wasn’t being used any more. Either way their teak inlayed carbon fiber boards are sweet.
Ryan L.
Consider paddle lever-arm ratios also
– Last Updated: Feb-11-12 4:13 PM EST –
The reduced mechanical advantage of stand-up paddling has been discussed here before, but I just tried to quantify that mathematically. I looked at the instructional video on this site and took measurements of hand positions along the shaft and the distance of the center of the blade from the lower hand. That guy appeared to be pretty average in height, so I did the same procedure for a kneeling-style canoe paddle that would fit him, or perhaps be a tad too long (it's one of my own paddles that's a bit too short for me). Using basic lever-arm principles, I calculate that for a constant amount of propulsive power generated by the blade, the amount of force that must be applied by the top hand and bottom hand of a stand-up paddler is 1.3 and 1.2 times as great, respectively, as for the same paddler kneeling in a canoe. If one were to compare SUP lever-arm ratios to those used by someone sitting in a canoe with a bent-shaft paddle (these paddles are shorter than paddles made for kneeling), the relative reduction in mechanical advantage for the SUPer would be even greater. Lever-arm mechanical advantage, or disadvantage as the case may be, is easy to measure and it is not possible to generate the same paddle-blade force against the water when stand-up paddling as when canoeing except by applying greater force with your hands.
Now, add to that another problem having to do with lever mechanics, this time within the paddler's own body. Notice how SUPers place their lower hand farther down the shaft, relative to their body, than people do when canoe paddling (note that if they did NOT do this, they'd have to work even harder, and anyone who's lifted and thrown dirt with a long-handled shovel knows all about this). The lower hand is thus in a less efficient position for applying a rearward-directed force. I can illustrate the principle this way: If you had to pull the starter rope of an outboard motor, would you stand up and swing your arm in an arc, pulling your hand past your body at hip level, or would you sit down and pull the rope straight toward your shoulder? It's no contest which is easier on the body and requires less muscle exertion. The lower hand when paddling a canoe is already in a less-than-ideal position for rearward pulling, but putting that hand even lower, as is the case when stand-up paddling, only makes a bad situation worse.
Bottom line, one needs to be stronger and tougher to provide the same amount of propulsive force with a stand-up paddle than with a shorter paddle that's used while kneeling or sitting.
"Reduced Mechanical Advantage?"
No way! There’s more mechanical advantage, since you’re using a longer lever. The top arm is the force, and the load (board/paddler) is moving in the direction of the force. If you use your bottom arm as the force, then the board/paddler should be moving backwards in the direction of the force, like in your shovel example of moving whatever: snow or dirt? You have a choice: move the board/paddler forward or just shovel water backwards?
Levers work both ways
– Last Updated: Feb-11-12 7:40 PM EST –
Your description of the direction of boat movement relative to directions of force shows you do not understand levers at all. BOTH hands apply force when paddling, albeit in opposite directions from each other. Read this before proceding:
http://www.edinformatics.com/math_science/simple_machines/lever.htm
If you think of your lower hand as the fulcrum, the force applied by that fulcrum to the shaft is by definition opposite of the direction of force applied to the paddle at its opposite ends. Get it? As described below, it actually makes no difference which point of force you define as the fulcrum (different classes of levers), but if you want to keep it simple, think of the lower hand as the fulcrum, and the paddle shaft as a teeter-totter with forces applied in the same direction at both ends.
Also, based on what you said, it's clearly necessary to explain that there's a difference between direction of force applied to the paddle at the three contact locations, and the force applied by the paddle TO those three contacts. I describe the forces applied by the hands to the shaft as related to the force applied by the blade to the water, but just remember that the force applied by the blade to the water is the same as that applied by the water to the blade. Thus, you can think of three points of contact along the length of the paddle, and three forces applied to the paddle at those locations,just like in diagrams of a lever. Most lever diagrams don't actually show the direction of force applied to the lever by the fulcrum, but you should be able to see what's happening anyway.
Now to continue.
The principle of my previous post has absolutely nothing to do with overall length. It's solely affected by the ratio of the length that's beyond your lower hand to the length that's between your two hands. Make that lower length proportionately longer than the length that's between your two hands, and the hands must apply more force to create the same paddle-to-water force. If you start with a paddle having the shaft length below your lower hand longer than what's between your two hands (this may already be the case with a canoe paddle), but then make that lower shaft length longer still (as with a stand-up paddle), the already reduced level of mechanical advantage of the canoe paddle simply gets worse than it already was. If you had really long arms but very short legs, you'd be able to keep the ratio of blade-to-hand shaft length relative to the between-hands length the same while stand-up paddling, and in that case the stand-up paddle would have no advantage or disadvantage relative to the canoe paddle, but it would take an oddly built person to accomplish that (and there would still be the issue of favorable mechanics of the lower arm, as described in my earlier post).
Two examples:
#1. If you could reduce the length of the shaft between the center of the blade and the lower hand to one-third of the length of shaft that's between the two hands (this would be a very short paddle), you'd have a 3:1 advantage for the upper hand as compared to the force applied to the water by the blade (the force carried by the lower hand will be the force applied by the upper hand plus the force applied to the water by the blade).
#2. If the length of shaft between the lower hand and the center of the blade is twice as long as the length of shaft occurring between the two hands, the force applied by the upper hand is twice the force applied by the blade to the water. Another way of looking at that is that the blade applies half as much force as the upper hand (again, the force applied by the lower hand is the sum of the forces applied by the upper hand and the force of the blade applied to the water, so it's substantially greater than with the short paddle also).
Try this simple experiment. Pick up a big rock with a short-handled shovel. Now, pick up the same rock with a long handled shovel, but with your hands the same distance apart as they were with the other shovel. You will immediately understand that overall length means nothing, and that the ratio of handle length between the shovel blade and the lower hand, as compared to the length of handle that's between your two hands is the only thing that matters. The more space you get between your hands RELATIVE to the distance between the blade and the closest hand, the less effort you must exert to lift the rock, so the long-handled shovel has the potential to be the better tool, but unfortunately, with a stand-up paddle, you cannot put your lower hand close enough to the blade to achieve this advantage. Go outside and try the shovel experiment. You'll see.
Here's another example to show you why there's more to it than length. A person can easily pry one end of a large car completely off the ground with a lever that's 20 feet long, so yes, "longer" is good, but it only works if the ratio of lengths on each side of the fulcum are favorable to the person operating the lever. Put the fulcrum close to the person instead of close to the car and the mechanical advantage is backwards and the person will not be able to lift the car. Less extreme than "backwards" is moving the fulcrum a little too far away from its ideal position close to the car, and again the lever operator will not be able to lift the car. This second case is the same as what happens when you switch from a short paddle to a long one without providing increased spacing between the two hands in the same proportion. That's what I mean by "reduced" mechanical advantage.
When applying this principle to paddles, which of the three points of force application should be called the fulcrum is a bit vague because all points are moving in space. However, mathematically it actually makes no difference which class of lever you call the thing (that is, which point of force application is defined as the fulcrum). The relationships of the different magnitudes of forces at the three different contact points, as determined by the ratios of shaft length between those contact points, will be the same no matter how you classify the lever.
in a canoe …
… I believe sitting and paddling is a much greater advantage than standing and paddling for speed and energy use efficiency , or at least it’s that way for me . Standing and paddling slowly while fishing the various cover along the shoreline is great , but I just can’t imagine staying standing up and crossing the lake given I have the option to sit down and do that .
Who would win the race in a canoe between a standing paddler and a sitting one (same canoe) ??
Maybe SUP’s are designed to be more hydrodynamically efficient than canoes , but I don’t think so … and even if so , don’t think it could be any great difference .
My own personal experience in either of my canoes is that sitting and paddling far exceeds standing and paddling as to what you get for what you put out .
Can you stand and paddle a sleek kayak (I would think so ??) . How about the same scenario just mentioned in the canoe , but instead it’s a sleek kayak now . Sitting still seems to be the all out winner .
I’d imagine a reasonable amount of stability has to be designed into any SUP , wider ones having more stability , narrower ones less … very similar to canoes and yaks I’d think .
But just how much stability can be forsaken in a SUP given the center of gravity is really up there in the air when compared to kneeling/sitting in a canoe or kayak .
Wonder how the wind resisitence comes into play ?? Canoe has more surface exposed than kayak … SUP has the least exposure I’d think . But how’s that compare to the human “sail” paddling the SUP ?? Maybe SUPer has advantage on a direct tailwind cause the body becomes a sail , but crosswind or headwind the SUper must surely have a serious disadvantage (??) .
running the downwind with …
… following seas looks to be the perfect application for a SUP . Very similar to any type surfing , let the wind and water do most of the work .
It’s power, not force, that’s important
The analysis is correct insofar as it’s applicable. Yes, the mechanics allow you to apply more force to the paddle blade when sitting close to the water, but over a shorter stroke distance. It’s just like being in low gear. What’s important is how much work it takes per mile while maintaining cruising speed (work being force times distance.)
So to use your shovel analogy but incorporate work, let’s say you had to move a big pile of dirt 10 feet from where it sits. With the “canoe mechanics,” you would take big shovel fulls with your hands near the blade, but have to carry them further. With the “weaker” SUP mechanics, with your hands further from the blade (and the ratios you describe), you would take smaller amounts each time but be able to easily swing them over to the new pile. It’s necessarily the same amount of work, and likely done in the same amount of time (and therefore with same power, because power equals work done per unit of time.)
Realize that SUP paddlers can always kneel and choke up on the paddle, and sometimes do in a big headwind, not just to reduce sail area and increase stability, but also to get that “low gear” when needed.
One last thing about the SUP stroke not considered, and not shown in the stroke illustrated on this site, is that a good stroke also involves leaning out and putting a lot of body weight on the paddle during the power phase for “free” force. You can see this in the 2nd half of Danny Ching’s video at http://www.youtube.com/watch?v=43AMhZNcImo
For a complete SUP stroke analysis video, see http://www.youtube.com/watch?v=e3uxyS-art8. If you do the math, the paddlers studied, other than the beginner, seem to be cruising at 5-6 mph.
I realize the analysis isn’t perfect
– Last Updated: Feb-11-12 9:13 PM EST –
However, the tradeoff between short strokes with more mechanical advantage versus long strokes with less mechanical advantage isn't really much of an issue. Being in "low gear" when paddling with a short paddle isn't the same as low gear with machines, because we are not operating anywhere near our limits of speed of motion when paddling. A machine in low gear, such as a bicycle or car, simply can't achieve as much speed when making use of mechanical advantage, but a person can swing the shortest possible paddle through its stroke many times faster than we can make our boats move, so there is not the same kind of limit on attainable speed simply due to "gearing" in this case.
It's true that strokes are shorter with shorter paddles. In rowing, this principle really comes into play. Long oars work really well because, because all other proportions being the same, a longer oar keeps its blade in a more ideal position for applying power than a short one, assuming an equal-length pull on the handles no matter the oar length (and of course if the ratios of inboard to outboard length are the same, the force needed to pull the oar will be the same as well, so keeping the blade in a more efficient arc with the longer oar has no downside whatsoever). The thing with rowing is that the direction of applied force is nearly ideal, much like in my previous example, pulling an outboard motor's starter rope toward the shoulder is immensely easier than swinging the arm in an arc to accomplish the same pull. Thus, the amount of force that's comfortable and sustainable when rowing is much greater than when paddling. There MAY be a similar difference in the biomechanics of applied force when stand-up paddling versus sitting or kneeling, but common sense doesn't suggest it since the point of application of force is so far out-of-line with the point of contact with the boat. I have trouble believing that such things as moving the body in certain ways can counteract the difficulty associated with misalignment between the point of force application to the paddle and the paddler's point of contact with the boat. The closer we can apply forces in-line with the desired motion, the easier things are to move. Would you be comfortable with the idea that when reaching down from several feet higher above the water, from a taller boat with a longer paddle, you could compensate for the loss of mechanical advantage with the longer stroke or by how your moved the core of your body in the process? Shouldn't this sort of disadvantage grow on a continuum, rather than reversing itself partway along the scale? Further, the stand-up paddler is doing a lot of extra motion that a sitting paddler need not do, lifting his whole body up and down and raising the upper hand nearly as high as he car reach during every recovery. In most sports, economy of movement is considered an advantage over extended time periods.
That summarizes my doubts about stand-up paddling being more efficient overall, but my original topic only dealt with the leverage aspects of using the paddle itself, which I think needs no modification.
shovel analogy …
– Last Updated: Feb-11-12 9:14 PM EST –
...... use apples and apples to make energy comparisons about low grip hand closer or farther from shovel face .
By apples I mean same amount of dirt (same weight) in the shovel for each type of shoveling style .
With the low grip hand as close as possible to the shovel face and the upper hand as far as possible away from lower hand (best arm spread) ... the energy required from the human will be far less .
The fulcrom being the low grip hand , the arm being the distance between hands . The greater the arm moment the greater the multiplication of the humans energy . The lever multiplies the energy . Short lever , less energy multiplication . Long lever , greater energy is multiplied .
The load (weight in shovel face) , will have that arm moment lever energy most effectively appllied to it if the load is closer to the fulcrom than farther away .
In short , a hand right up to the shovel face (low grip hand) , and upper hand as far away as possible will signifigently decrease the energy required to shovel the dirt pile .
Apples to apples , same weight of dirt in each shovel full .
Load as close as possible to fulcrom ... low grip hand is fulcrom ... greatest enery multipler is longest arm moment .
I've done a lot of digging and shoveling and I know what takes the least amount of energy to move the most amount of dirt ... it's the way I just described .
Imperfect world
We can definitely agree that it all comes down to ergonomics – translating body movements into paddle strokes. The dilemma is that the more we try to attain the idealized paddle movement (staight back, vertical, and next to the boat), the more we stray from using larger muscles. So, we look for some compromise in between. Rowing, as you said, is the most efficient translation. The canoe, kayak, and SUP stroke are much less efficient, but I really don’t know in what order. If someone equally proficient in all three were to compare them in the same craft, maybe one of those stand-up kayaks, we might have an answer.
No need to argue theory.
Check the race results at the link posted earlier in this thread. Do the math. The SUP’s lose.
Conclusions without supporting data
What are you comparing – outrigger canoes to SUPs? The discussion was concerning what stroke is more efficient – sitting or standing – for similarly shaped crafts. Specifically whether paddling a Wenonah Wilderness, which might have a waterline of about 14’ x 30" with a relatively flat bottom, would be faster than a SUP, presumably of similar dimensions. If you can point to data addressing that question, or even any two similarly shaped canoes vs SUPs, or kayaks vs SUPs, that would be on point. I think we already know that longer, narrower, more rounded hulls are capable of more speed.
Drawing Is Incorrect
Thank you GBG, for now I know what the problem is: the drawing for the 3rd class lever is incorrect. The position of the fulcrum should be above the lever rather than below it as pictured. Otherwise, it will not work. Try using a broom this way as pictured? Or even a fishing pole? It is commonly accepted that 3rd class levers offer hardly any mechanical advantage at all, and that’s why your shovel works the way you describe. In 5th grade science, my kid learned that the load moves in the opposite direction of the force using a first class lever like a seesaw. And that the load moves in the same direction of the force when using second and third class levers. Of course it would be more understandable if the picture of the 3rd class lever was correctly drawn with the fulcrum in the right position?
Several basic misunderstandings here
– Last Updated: Feb-12-12 11:30 AM EST –
First, as I said, it makes no difference which style of lever you call a paddle, because if you view it from the frame of reference of the paddle itself (in which case you observe no movement, only forces), then no matter what, the magnitude of the forces are related according to the ratios of shaft length between the various points of application of force. Also no matter what, the forces at each end will be in the same direction, and the force between the two ends will be in the opposite direction (remember that the fulcrum applies a force too, even if there's no need to think of it as a fulcrum when determining relative forces). Once you know their locations, you can calculate their relative magnitudes. That's all that needs to be said, but I'll try to address your confusion a bit too.
Quit thinking of the fulcrum in that third-class lever as a support that's only capable of applying force from the side where it's located. You are completely missing everything that matters here if you get hung up something like that. The fulcrum in that drawing is just a SYMBOL, like something you'd see on a map, NOT a realistic representation of an actual object. The purpose of the symbol is to show that the lever pivots at that point. Erase the triangle in your mind and replace it with a pin through a hole - anything to remind yourself that the lever can only pivot at that location rather than move laterally through space. But again, none of this matters if you view the lever within its own frame of reference rather than as a bystander watching its motion from outside the system. The second AND third class levers are closest to explaining paddle action because the blade in the water comes closest of the three contact points to functioning as a fulcrum, since the blade is the part that most closely approximates an immovable point in space. Your broom example puts the fulcrum at the location of your top hand, and defining a paddle that way is not wrong either. It all depends on your frame of reference, and if the boat is your frame of reference it comes close to being correct. It gets confusing though, because the actual load as viewed from an independent observer in space is the boat itself and the boat is moving through space, which is why the paddle blade becomes the fulcrum. In that case, which hand you call the input and which you call the output defies definition because both sources of force are attached to the load that's being moved (the boat) by means of your body and are moving forward with that load. That's why it's best to view the lever from within itself, not from the outside (not from your position in the boat, and not as a bystander). That way, nothing matters when it comes to definitions. No matter how you define the lever, a simple diagram showing the locations of the three forces applied TO the lever, with the one in the middle being in the opposite direction of the ones at the ends, DOES allow you to figure out that the force applied closer to the paddle blade (makes no difference if you call that hand input or output) is greater than the force applied by the hand at the end of the lever (again, no difference whether you call it input or output). It also allows you to calculate the magnitude of all these forces relative to each other (including the force that occurs at the fulcrum), based on shaft length occurring between them. Further, it also allows you to calculate how those loads increase if the overall proportion of shaft length between the lower hand and blade increases.
I will show you my actual calculations from my original post if you think that will help you see what I've been saying.
Of Course It Makes A Difference
That’s why there are three (3) classes of levers. And uniquely, a paddle can be used as a first, second, and third class lever depending on the work to be performed. However, only one of the levers will propel a canoe forward. Know which one it is? Hint: As a “grasshopper,” canoe guru, Patrick Moore would always remind me that “the purpose of the top hand/arm was to move the bottom hand/arm forward.”
ps: know what the purpose of the bottom hand is?
You have not understood even one word
– Last Updated: Feb-13-12 10:21 PM EST –
Your various responses, including this last one, clearly show that you do not understand the meaning of "frame of reference", and you do not understand that the three forces acting on a lever can be analyzed based where they are located along its length. You still do not have any clue that knowing locations where the forces are applied and the magnitude of any ONE of the forces allows you to calculate the magnitudes of the other two.
You clearly do not understand that every class of lever has the forces at each end aligned in the same direction, and the force applied between those two ends (middle contact point) in the opposite direction, or that the force applied to the middle contact point is always the sum of the forces applied at the two ends. Nothing else is possible but you still don't get it. If you did, you would not still be claiming that I'm missing something.
I offered to show you the math calculations used to compare the force that must be applied by each hand on the paddle shaft, for both of the paddle types we were talking about (calculations based on measured hand positions and distance from the lower hand to the blade) necessary to create the same propulsive force with both kinds of paddle. It seems you are not interested in such details and it's clear now that you cannot understand such things. I see now that all you will do is respond in the same tone as your earlier comment that "every 5th grader knows" this or that basic thing about levers. Well, before switching to my current line of work I taught several different science subjects at both the middle-school and secondary-school level, and can tell you that the principles of frame of reference, and even the "proportional" math used to calculate the force magnitudes on a working lever is not introduced until college-prep level in high school or sometimes even college. The concepts are simple in their own way, but way beyond what 90 percent of middle-school kids can comprehend, which is why they are not asked to understand such things. Seems like it's beyond your level of understanding as well. Nevertheless, if you want to see the calculations that I used to determine the relative differences in force needed to drive these two kinds of paddles (and of course that will require me to supply my hand-position and lower-shaft length data as well), I'm happy to do so. Heck, I'll even demonstrate mathematically that every class of lever will undergo the exact same forces if the force at one end is the same in all three cases, and if the proportional distances between the three contact points are the same (in a case like that, the only difference will be which contact points are called "input", "output" and "fulcrum"). Would you check it out if I did so? Or would you just throw a handful familiar words at me and think you are making sense?
Okay, here's an easier trick which is perfect for you because all it takes is a middle-school level of comprehension, along with the knowledge that force at the middle location on the lever is always in the opposite direction as the two end forces, and that its magnitude is the sum of those other two. For each class of lever, draw in the missing arrow representing the direction and magnitude of force that is applied to the lever at the location of the fulcrum. Using middle-school logic and understanding, use bigger arrows for bigger forces and smaller arrows for smaller forces. THEN notice that the force diagrams for all three levers have become identical! If you can understand why the diagrams are now identical, you can also understand why all you need to do is analyze the forces in terms of what is experienced by the lever itself (viewing the system from the frame of reference of the lever). Just try not to get confused by arrows which might already be on the diagram showing direction of movement (in some cases they are in the same direction and in other cases they are not - you need to know which is which).
).
No Math, No Tricks, Just Horse Sense
And the work I’ve got to do is move my canoe off the beach and up to the grassy area using just my canoe paddle and a length of line. I’ve got three (3) choices:
(1) Use the paddle as a first class lever by attaching one end of the line to the bow of the canoe and the other end to the blade end of the paddle. Standing in front of the canoe and facing it (with the line fully stretched and taut) and holding the paddle in normal fashion with the top hand as the force and the bottom hand as the fulcrum, exert force with the top hand by pushing the palm grip towards the canoe. What happens? If it’s light enough, the canoe (load) moves in the opposite (forward) direction of the force.
(2) Use the paddle as a second class lever by moving the line off the blade and attaching it to the middle of the paddle shaft. Now bury the blade of the paddle into the sand (fulcrum). With the blade buried in the sand and the line taut, exert force by pushing the palm grip (top of paddle) forward towards the grassy area. The canoe (load) moves in the direction of the force.
(3) Use the paddle as a third class lever by leaving the blade buried in the sand and reattaching the line to the top of the paddle or palm grip. Now exert force by pushing the middle of the shaft forward towards the grassy area, and you’ll find that the canoe moves forward in the same direction as the force.
So now go do your math and tell me which lever works best or has the mechanical advantage in performing this specific task?