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Rain Cape Pros:
For commuter bicycling in rainy weather, I find a rain cape combined with
having full wrap fenders is very practical. The cape does not become
a sweat box like rain coat or rain clothing becomes. Under the rain
cape, I can wear normal clothing and mostly keep my feet and pant legs dry
and clean. The rain cape is easy to take on and off, so that I can
just remove the cape at a store or at work and be ready for normal pedestrian
activity. The rain cape can also be practical, if awkward, for just
walking in the rain. The cape is loose enough that I can move an arm
out for signaling my turning intentions.
This bright yellow looks eye catching and I like having bright clothing
and reflective clothing at night for bike riding. Even with very bright
clothing I have had numerous occasions when I have stopped at a 4 way stop
and the cross traffic auto drivers still do not see me (especially people
making the very common rolling right turn). I have no doubt that, even
though I stopped and waited my proper turn at the 4 way stop and took a position
in the center of the lane so I was more visible, for those drivers who did
not see me, they must think that I just leapt out madly in front of them
and they probably wish I would follow the rules of the road.
Rain Cape Cons:
I find that the cape somewhat restricts my ability to look backward over
my shoulder if I am holding the frabic streatched tight.
Also, when going over 20 mph down a steep hill, I have felt some vibration
turbulence that made the bike feel less steady than without the cape, probably
because the way I hold the cape over the handle bars will transmit wind
turbulence directly to the steering.
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In order to estimate the wind drag of this rain cape, I performed a coasting
test measuring average speed and maximum speed coasting down a 3.6 % paved
slope on a day with no wind, slight rain, temperature of 47 degrees F, and
humidity 90%. I coasted the same section once with the rain cape as
shown and once with fleece jacket, moderately snug fitting.
Using a power calculating spread sheet I found on the web years ago
(based on Bicycling Science by David Gorden Wilson), I could
enter the data and adjust the coefficient of aerodynamic drag parameter
to match the two results so that for the known slope the calculation gave
a zero effort power input for the known speeds. In the case of
the performance without the rain cape I estimated a coefficient of drag
at 1.2, and this projected into a number of 1.4 to 1.5 for the rain cape
performance. This calculation implies an extra energy effort of 43
to 64 kcal per hour is needed to pedal at 12.4 mph (20 kph) with the rain
cape on as opposed to a fleece jacket over a sweater all zipped up snug.
These calculations also included the known 3 watt resistance of my
shimano hub generator.
I made this cape from goretex bought at a cheap price as a remnant sale.
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