Clive George wrote:

"JNugent" wrote:

I think he mentioned them as a way of highlighting the idiocy of
banning a unicycle...

Why?

Do rucksacks also have hardened steel sharp bits sticking out and/or
covered in black grease as well?

Do unicycles?

If they operate in the same way as bicycles, the answer must be "yes".

Not that you see too many of them.