On 17 May 2004 17:17:23 -0700,
[email protected] (Chalo) wrote:
>
[email protected] wrote:
>
>> David Damerell writes:
>>
>> > Lately I have had the urge to get a penny-farthing. I'm
>> > wondering if any r.b.t. types already own such bikes,
>> > or know of competent manufacturers - Google suggests
>> > some people still make them, but are they any good?
>>
>> No.
>>
>> Consider that most bicycling on the level is done in a
>> gear above 85 inches (the way gears were measured in
>> respect to these bicycles) which means a wheel diameter
>> of 85 inches. A 52-13 for instance is a 108 inch gear for
>> comparison. Your inseam minus about 2 inches times two is
>> the largest wheel radius you can ride. That's about a 62
>> inch high wheeled bicycle. You'll need to do a lot of
>> spinning.
>
>The only single-speed bikes geared as high as 85 inches are
>those for the velodrome, which has no hills, corners, or
>bad surfaces. A BMX bike typically uses a 55 inch gear, a
>single-speed MTB about 52 inches, and a balloon-tire criser
>anything from the mid-50s to the mid-60s.
>
>When I was exceptionally fit and I lived in the gently
>rolling terrain of Austin, Texas, I used an 81 inch gear
>on my fast cruiser. Here in hilly Seattle, all my one-
>speed bikes sport something around 64 gear inches-- even
>the fixie.
>
>By using shorter cranks, one can use a larger wheel and a
>higher "gain ratio" at the same time. High speed is thus
>available to a high-wheel rider who opts to sacrifice hill-
>climbing and acceleration.
>
>High-wheeling is by nature a more leisurely activity than
>your own riding, if you use an 85 inch gear to cruise
>around. If you could only choose one, though, I bet you
>would not ride a gear quite that high.
>
>> On top of that, you can't stop worth a damn because rider
>> CG is close to vertically above the ground contact point
>> of the wheel, so forward dismounts are a skill to master.
>
>Another reason to keep speeds modest when riding the wheel.
>
>> They are nice to view in museums but don't ride them.
>> They have solid tires and the rider sits directly in line
>> with road shock on no cushioning.
>
>The gentle vertical accelerations imparted by a four to six-
>foot wheel rolling over irregularities require none of the
>cushioning a squishy tire imparts. You will remember that
>it was Dr. Dunlop's invention of the air bladder tire that
>allowed safety bikes to come into general use. Those were
>the bikes whose ride qualities suffered for lack of
>cushioning.
>
>> The riders crotch must be as close to the wheel as
>> possible to get a reasonably large gear. You can imagine
>> who won races in those days. They were pretty tall.
>
>I can find no virtue in a technology on the basis that it
>confers a competitive advantage to short people, Jobst. I
>wonder why you would! ;D
>
>Chalo Colina
Dear Chalo,
Nice point about huge wheels rolling more smoothly.
Tiny but inquiring minds now want to know your preference.
Penny-farthing or tall-bike?
One of Leona's Little People
