Helen Deborah Vecht wrote:

"JNugent" typed

Do unicycles?

If they operate in the same way as bicycles, the answer must be
"yes". Not that you see too many of them.

You obviously don't see them, or look at them then. Unicycles are
driven directly without gears, cog or a chain...

Not all of them, clearly.

The only one I have ever seen "in the flesh" definitely had a crank wheel
attached to the pedals and a gear chain driving the wheel.

It er... some years ago...

I have not seen another these last... thirty+ years?

Is it known that any are in use as pukka transport?