# 'power per stroke' - a misnomer

The Epic web site states, “The Epic Large Wing is designed for paddlers desiring maximum power per stroke.” Others use “power per stroke” as well, which seems to me poor terminology. In particular, if one were to multiply the power per stroke by the number of strokes one takes in a minute, one would expect to compute the total power applied during that minute. This makes no sense since power is already the rate of doing work. A better expression would be work or energy per stroke.

But not only that. A larger paddle does not necessarily produce more work or energy per stroke. It depends on the paddler. Some paddlers will be able to produce more energy per stroke with a smaller blade by pulling that blade faster through the water, but with less force.

Oh My God!

– Last Updated: Jun-24-13 10:03 PM EST –

You must be an engineer.

Probably don't believe in magical boats either. Do ya?

Agreed

– Last Updated: Jun-24-13 11:31 PM EST –

I tend to agree with your statement, 'work per paddle stroke' would be better.

However, it occurs to me that 'maximum power per stroke' may be a botched attempt to say 'higher average power per stroke', which is perhaps a reasonable statement for a big honkin' paddle blade.

But I still get tired and sore from paddling.

Can you explain that to me?

power and speed
For any boat, not just a kayak, if you increase power the speed will increase. Maintaining any constant boat speed requires maintaining a constant (average) power. Work/stroke multiplied by strokes/minute will give work/minute, or power (average).

An auto engine produces max power at an rpm specific to that engine. It is more complicated for a human paddler who must choose a blade size, paddle length and stroke rate for max power. Choosing a larger blade might or might not result in higher max power (and speed).

Efficiency is another issue. Energy is lost in (at least) two places; at the interaction of the blade and the water, and in the muscles of the body. If a paddler wants to be most efficient at, say, 4 kts, there will again be a particular combination of blade size, paddle length and stroke rate that depends on that particular paddler’s body capability, and, very importantly, his technique.

True

– Last Updated: Jun-25-13 12:42 AM EST –

I think the Epic statement is trying to say that the paddle creates more power, therefore you will necessarily go faster.

But there is another issue - as drag increases with speed, large increases in power will create relatively modest speed increase of the boat. Just because the paddler moves the paddle faster and expends more power doesn't mean the boat always speeds up proportionately.

Right
And The Discovery Channel almost always gets “force” and “Pressure” wrong.

Laypeople often misuse technical words.

yes, but sounds sexy
You are right, power-per-stroke is somewhat pointless, since power is work done over a given time.

Of course, paddles, especially Epic, are “scientifically” designed to perform for quite narrow range of speeds, so one could then retort that the perfect stroke is defined, then the power is maximized. As a matter of fact, if one were to observe K1 sprints at the Olympic or World Championship level they would notice that the top paddlers are going at it stroke per stroke. To get a bit deeper into details, if your stokes were 1 second, power-per-stroke and work-per-stroke would have exactly the same numerical value.

Now, all this pseudo-scientific BS aside,

“Power” is sexy, “Work” is chore!

Larger Blade does note equal more Power
A larger blade does not equal more power unless you are strong enough to pull it through the water. That is like saying if I get a huge bike gear I will have more power. Not true if I can’t push the peddles. I think many people paddle with blades to big for them. Just because gold medal winner Greg Barton can use the Epic Large Wing paddle does not mean it will work the same for little old me.

I really like big blades, but the engine has to have enough power to drive them. People tell me that such-and-such paddle is really powerful. I tell them that I hope they have the power to use it!

I’m more of a low-cadence, big blade, kind of guy. I think it’s fun to really dig in and that big ol’ blade grabs hard and bites back. Not strong enough to do that for any distance, but sprints are a hoot!

Yeah, most folks, myself included, don’t know the technical definitions of certain words like power, work, etc. In physics, those definitions are critical in order to communicate efficiently, but most of us don’t have that background. I knew a lot of that stuff years ago, but then, that was years ago!

That is absolutely true for me
For a long time I was using an Epic wing and did great with it, but as I got older, it was working me harder and harder.

I switched to a ONNO much smaller wing, and did just as good if not better and was much less beat at the end of a race.

I sold the Epic to some one on P-net back a few years ago and have used the smaller one ever since with great results. ( it absolutely made up the difference on my getting older)

Jack L

Wing reflections
I’d put myself in the well conditioned, broad shouldered, high angle, high motor, power stroke category. I usually use a carbon werner, but acquired an Epic Mid Wing for a great deal.

A few weekends ago I tested the epic over a weekend to see if I’d want to transition from the bigger bladed werner to the wing. What I learned is that it does take a well conditioned motor to power a wing paddle all day. Towards the end of day one, my form started to breakdown and I was a lot more tired than my usual blade. There is no cheating with a wing, you have to be on your mark and properly stroking to take advantage of the technology.

By the end of the day I did feel beat up and more tired and found myself looking to switch back to my regular touring paddle.

In summary, I’d use the wing again for a day paddle and most definately a race. I have the conditioning to power this blade for a race length outing and a day of start and stop day paddling. I’d need to spend some serious time with the blade to make it my everyday stick or to have enough conditioning to use it over an extended touring trip. Plus you have the added bracing reliabiliy of a traditional euro paddle.

The “barton-like” guys in the surf skis are carrying a lot less weight and only have to think about straightline speed. Some on this board do use wing paddles full time, but I’m guessing you are on the water more than me to build the stamina.

the assumption is you have a truly awesome kayak (an Epic of course) that has a high hull speed. It’s also assumed YOU are an incredibly strong paddler and the only thing that’s been holding you up is that wimpy toothpick you call a paddle. With those assumptions I think you can make an argument that their paddle could give you more power.

Marketing - A world of its own
Never confuse marketing with the real world.

More enginnering stuff
You don’t pull the blade through the water. The blade sticks and you pull the boat through the water.

In reality the blade does have some slip, like slip in a boat propeller, but it is less than you think. So in this case a larger blade might have less slip or it might not depending on the force being applied to it.

I think you should get one of the strain gauges with telemetry recording capabilities for your paddle like the Olympians are using these days to get the exact right paddle for your body and paddling style.

I think it was to make g2d get po’d
jack L

Slick tech for paddle data capture
I wrote an article back in 2010 about it