Flex in a paddle

How much, is too much, or too little, flex

and what are pros/cons of paddle flex ?

How is it labled, marketed, known upon purchase ?

If it flexes a lot, is the paddler pulling to hard

or, perhaps it made to do that for some reason ?

Too little, too much . . .

– Last Updated: Dec-12-12 5:04 PM EST –

Flex can come from the blade, the shaft, or both.

Too little flex and you may begin to feel it in your bands, wrist, and shoulders. When switching to a paddle with less flex, you may notice that the paddle feels stiff and a little bit "dead" in your hands. A stiffer paddle is more efficient and therefore well-suited for anyone looking to get a boost in speed or power.

A moderate amount of flex gives a paddle a lively feel. The paddle provides a crisp little "snap" at the end of the stroke. It can be more forgiving on the joints and is well-suited for long-distance touring.

Too much flex results in a loss of power and efficiency. No one wants to propel their boat with a noodly paddle -- but there are some of these paddles out there. These paddles are usually in the less expensive -- and that is probably their only asset.

I don't know of any manufacturer using a rating system for paddle flex -- but it's a good idea.

personal taste
how much is too much is a matter of taste.

stiff paddle:

pro: more power in a sprint.

con: more damage to your joints

Only seen it labeled in racing blades. Epic paddles and other racing blades are available in different stiffness shafts.

If it flexes a lot, is the paddler pulling to hard

or, perhaps it made to do that for some reason ?

Pulling hard and flexing the shaft a lot only happens in a sprint and starting off fast. If you are trying to go fast by pulling hard all the time, you’re doing it wrong. A wood greenland stick flexes a lot and will lose out to a carbon blade in a the first few strokes but over a day’s paddle or even an hour it won’t matter. Just ask Joe O’Blenis.

My Opinion

– Last Updated: Dec-12-12 5:23 PM EST –

I really think it's a personal preference thing. Coming from a road bicycle background; side to side flex in a bike frame is a bad thing. Energy that should be devoted to forward motion is lost. Fore and aft flex absorbs road shock and less forward energy is lost. I ain't no fizzicyst but when your paddle flexes forward and back, very little energy is lost. If it feels good, enjoy it.

As Kudzu says, if the flex is in the paddling direction, and the unflexing happens underwater, not much energy is lost.

If the unflexing happens upon exiting the water (i.e. you’re still pulling hard when the blade leaves the water) then the energy that went into flexing will be lost - it goes into flinging that paddle blade full of water backwards.

Rating systems for flex
Should more manufacturers address the issue of flex ?

It is a highly repetitive motion involving action/reaction

Isn’t That What the “fizzicyst” Describe
As Elastic Potential Energy (EPA)?

I like a little flex
I have had super stiff paddles and recently changed to a paddle with some flex for whitewater. For me the flex seems to give it more feel. Similar to riding a steel bike frame over an aluminum frame. Or a wood handled tool compared to a steel handled tool. It’s hard to describe but no flex just doesn’t have the feel that I prefer. It is likely preference.

Paddle flex
Since it’s pretty much a personal preference thing, I don’t see any point in rating flex as a marketing tool. The degree of flex is easy to determine when you examine a paddle. Some like it stiff, some like flex.

Use whatever you prefer.

Indeed it is…
…and now all we have to do is to get manufacturers to measure and list an effective spring constant for their paddles. OK, probably not gonna happen…

The topic was indeed FLEX

– Last Updated: Dec-13-12 1:29 PM EST –

Many sports that involve a ""stick"" also involve FLEX
- golf (huge, huge range of variability here)
- baseball (some like aluminum some like wood)
- hockey (material changed thru the years)
- lacrose ( differet flex for different positions)

Kayaking paddles are made of a multitude of materials

Marketing that "Flex" thingy (as ambiguous as it might be)
- might actually be a topic/subject people latch onto

Once you buy a paddle - you're stuck.
Hopefully you had a chance to demo it somewhere.
Maybe a buddy lent you one for a session.

Picking one off the shelf or off the internet is tough

People are unique - no doubt about that.
We all paddle various conditions, weather, etc., etc.
Some days we go hard, some days we cruise, others we float

SIDENOTE - something wonky happened here -
other people had replied below Jerry and now
its gone, lost, invisible, etc.

Evaluating Flex

– Last Updated: Dec-13-12 2:36 PM EST –

You make a good point that picking a paddle "off the shelf" is a tough way to know what you are getting. Fortunately, I think if a person pays attention to such things, he can get a fair idea what sort of flex is there before the purchase. I have two "identical" cedar paddles purchased many years apart. The second one was a quick replacement of the first, which is broken (until such time as I take on the rather big project of fixing it). The new one turned out to be MUCH too flexible, but it turns out that the difference is perfectly apparent simply by grasping each paddle the normal way and forcing the tip of the blade against the floor, in a motion similar to pulling the blade through the water (I actually can test the broken paddle this way too because the broken spot only yields in one direction).

In the "old days", a person experienced with high-quality road bikes could get a pretty accurate idea of the flex in a bike's frame by standing alongside it while grasping the seat and handlebars, then pushing sideways on the crank hub with one foot. I bet a person who wants to, could develop a feel for paddle flex in similar fashion.

I use slalom paddles for paddling
whitewater, and my Mitchell is flexible in both the glassed wood blade, and in its carbon shaft. Mitchell calibrated the flex very effectively. Gives excellent feedback, and on forward strokes, the flex makes the slightly trailing blade act like a bent shaft. I’m sure I get that energy back before the stroke is finished.

The Mitchell’s flex has also saved the blade on occasions when a hard stroke has hooked a rock on the bottom. I can feel the blade bend and then slip off.

But it is awfully easy for a paddle maker to crank in too much flex. A little is good, more is not better.

I prefer a bit of flex.
I like the Epic burgundy shaft flex. Their green shaft seems a bit stiff for my liking.

I recently switched from a one-piece fiberglass to a one piece carbon fiber (same design, lighter weight) for running Class II-III whitewater.

The CF paddle is lighter and more responsive and probably a little more durable. It is stiff and when you bang a rock or something you definitely feel it in your arms. I notice the difference most when accelerating (including changing direction).

For my rec boats, I have a couple of CF sharf/poly blade combos and I really like those as well. I’m not crazy about most of the aluminum shart paddles I’ve picked up in stores. Some have a noticeable wobble where the two pieces connect. If you hold a paddle in the center and shake it back and forth, you can feel the stiffness of the shaft and compare paddles to some degree. And you kinda know that plastic will flex more than glass and glass more than CF.

It boils down to what you need your paddle to do and whether or not it makes much difference to get something “better” – whatever “better” means to you.


Testing flex

– Last Updated: Dec-13-12 5:51 PM EST –

Someone suggested - grasping each paddle the normal way
and forcing the tip of the blade against the floor...

Doesn't that only test the "blade" at the tip ?

Wouldn't you want to put the entire "flat" area
of the paddle against a pole, column, wood beam, etc.
and see how the shaft flexes as well ?

I'm thinking - Blade Flex - does not equal - Shaft Flex
in fact they are often made of 2 different materials;
further complicating the touchy feely combo thingy.

Usually we submerge the blade a good ways to get some bite
in the water before the push/pull action takes place

Quite correct

– Last Updated: Dec-13-12 7:17 PM EST –

Yep, to know more about what's going on, you'd want to do something like that. In the example I gave, it actually was the blade portion which was responsible for "too much flex" in the newer version of those two paddles, and the flex could be seen as well as felt when tested in that way. I suppose in the interest of keeping things simple, one could do the same test I suggested, once pushing against the tip of the blade, once pushing against the base of the blade (thus feeling shaft flex only), and maybe once halfway in-between. That's still pretty crude though, and like the bike-frame example I mentioned, none of it would mean much without the experience to make a good interpretation.

One could devise complex tests that really explain things properly, and in an ideal world the paddle manufacturers would publish the specs. One would still need to experience the use of various paddles to interpret the specs though. Further, in the case of wood paddles, like the cedar ones I mentioned, two "identical" paddles might well have a night-and-day difference between them.

What system
If you talked to a manufacturer which direction

would you encourage them to go ?

  • color coding the shaft
  • numbers perhaps 1 thru 5
  • simple text perhaps hard, medium, soft

    Standardized across the board for all disciplines
  • other scenarios, systems, ideas ?

If your shoulders or biceps are stiff…
Use a paddle with more flex. I use a Lumpy that is really flexible compared to my other paddles, it gets the most miles per day. An Aquabound fiberglass paddle for rivers and surfing get the most waves per day for me. For a one day race I think the light stiff carbon shaft and blade paddle I have works best, but only for one day and then an off day after that.