From: Guillemot@aol.com
Date: Tue, 14 Mar 1995 22:10:38 -0500
Message-Id: <950314220707_49758190@aol.com>
To: baidarka@imagelan.com
Subject: Traditional Paddles new thoughts
Since I instigated the discussion that resulted in the two-part synopsis I
just posted, I have thought about the wide-vs-narrow problem further. "Wide"
and "narrow" are both relative terms that probably oversimplify the
differences between modern paddles and "traditional" designs. However, most
of the paddles shown in Zimmerly and Chappelle have a relatively narrow blade
length-vs-width proportion when compared to modern kayak paddles. Especially
when compared to white water paddles. Most of the proponents of the
traditional paddles refer to the "greenland style" paddles when speaking of
the advantages of the traditional designs.
I have become convinced that the lowered wind resistance of the atributed to
the narrower blade is a red herring. I typed the paddle dimensions on pg 16
of Zimmerly into my CAD program. From this I compared some measurements with
a "wide" paddle of my own design. Where "Z" is the Zimmerly paddle and "N" is
mine:
Area of the paddle face:
Z: 100 sq in
N: 112 sq in
Assuming both paddles are used unfeathered (I generally build to a 70 deg.
feather), my wide blade has only 12% more frontal area exposed to the wind.
All other things being equal this is not a huge difference.
Now start paddling. Because of the smaller paddle area, the narrow blade must
be moved faster through the water to generate the same force. The force
applied to the water is a function of the velocity of the paddle through the
water. At the same time, the force the air applies to the paddle is also a
similar function of the paddles velocity through the air. As best I can
figure on the back of an envelope, the higher paddle speed required to create
a given propulsion will result in an increase in wind resistance such that
the wind induced drag of the narrow and the wide paddle is about the same.
What I think is more important than the wind resistance question is the
paddling cadence used. Racing cyclists like to maintain a high cadence a
kayak paddler would see the same advantages.
Blade area effects the cadence. I think the force applied will be
approximately inversely proportional to blade area. In other words the
cadence required to go a given speed is also inversely proportional to blade
area. Another factor affecting the paddling cadence is the effective length
of the paddle. This will be related to the location of the center of effort
of the paddle which should be near the geometric center of the blade.
Distance from center of shaft to geometric center of blade:
Z: 33 in
N: 39 in
The cadence needed to go a given speed should be inversely proportional to
the effective length of the paddle. Given the area and effective length of
the two example paddles, this suggests a paddler using Z would have to paddle
at a cadence about 30% faster than when using N to go the same speed. This
probably an advantage. Bicycling I peddle at a cadence in the mid 60s to 70
rpm, a racer uses up near 100. I'm not sure what this means, but it suggests
a professional can maintain a 30% higher cadence then a novice and benefit
from it.
What becomes important is what cadence is a given paddler comfortable at when
paddling. Can the paddler maintain that cadence all day? I think there is an
advantage to the average paddler to use a paddle that promotes a higher
cadence. I also think that the original kayak builders would have had no
problem maintaining a comfortable fast cadence even with todays wide paddles.
Observe the Finlandia Challenge paddled with modern long, wide "wing"
paddles.