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Old October 17th 10, 08:37 PM posted to alt.rec.bicycles.recumbent,rec.bicycles.soc
Tom Sherman 起豺_2_]
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Default Pre-WW2 Czechoslovakia (I think) 'Bents (and other things)

On 10/17/2010 2:24 PM, Edward Dolan wrote:
"Tom Sherman wrote in message
...
On 10/17/2010 11:38 AM, Edward Dolan wrote:
"Tom Sherman wrote in message
...
I like the small wheel 'bents (in the first 58 seconds of the video).
Also
note that there is a bike very much like what became the "standard" SWB
'bent configuration in the US in the 1990's.

http://www.youtube.com/watch?v=jdlpJqHxLxk.

Those small wheel recumbents have wheels that are too small. You will
feel
every crack in the road with such wheels. However, note that the tires
were
fat. That is to absorb road shock, but what does it do for road friction?

For a given inflation pressure (and similar tire construction), a wider
tire will have LESS rolling resistance than a narrower tire, since the
casing deforms less at the contact patch.


Even so, does not a large wheel ride smoother than a small wheel?


All else being equal, which it is not with the small wheel using a wider
tire at a lower pressure (since the skinny large tire needs to be
inflated quite hard to reduce pinch flats).

Also, do
you not get a flywheel effect from a larger wheel?
[...]


Rotating inertia of a bicycle wheel is practically insignificant
compared to that of the whole bicycle and rider.

Try this experiment: Put the bicycle in a work stand or upside down, and
spin the rear wheel up very fast with the cranks. Wearing a HEAVY
leather glove, grab the wheel by the tire (being careful not to put your
fingers in the spokes) and see how easy it is to stop the wheel.
Alternatively, use the brake to stop the wheel, and see how fast it
stops. Now compare the stopping distance and time if you were riding at
an equivalent speed on a flat surface.

--
Tom Sherman - 42.435731,-83.985007
I am a vehicular cyclist.
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