how small is too small, wheel-wise?

I've been riding my 20" in the carpeted living room exclusivly for the last
couple of months. I find the smaller wheel much easier to control than the 24" I
was used to. Is a 16" even easier? Does it start getting harder with smaller
sizes at some point?

Yesterday I took the 20" on the bus for the first time. It fit under the seat
much more easily than the 24" (obviously.)

It was my first city commute ride since I first managed to idle and I thought
I'd be idling away at every traffic light but instead I was happy to grab a
light pole and rest.

Anyway, I started thinking, if you built a geared non-girrafe unicycle where the
rim went around a big hub, rather than the wheel turning on an axle, you'ld have
room inside the wheel for your gear train. The crank would turn around the
center like usual. The machine, if it could be built, would also be adaptable to
wheelchairs.

I've seen a gas powered wheel-thing with the same idea. The rider sat inside
the wheel and the wheel turned around him. Clear as mud, I'm sure unless
you've seen it.

Would it be too much friction to be practical for a person pedaled vehicle?

jh

Rick wrote:
[color=blue]> A collapsible giraffe would be really convenient![/color]

There's a busker in York, UK (probably elsewhere too), who has an exploding
giraffe. A small explosive charge goes off halfway down the seatpost, and
the uni snaps in two. Pretty amusing! I didn't see how he falls, but I'm
guessing it's pretty safe... the explosion takes your attention away from
how he gets off.

Cheers,

Stu

John hoy wrote:

[color=blue]>Yesterday I took the 20" on the bus for the first time. It fit under the seat[/color]
[color=blue]>much more easily than the 24" (obviously.)[/color]

Anyone ever put together a collapsible uni? Seems like it would be pretty easy
to do; flip up pedals, quick release on the seatpost, clips to hold the pieces
together, etc. A collapsible giraffe would be really convenient!

Rick