Ian Smith wrote:

On Tue, 24 May, JNugent wrote:
Ian Smith wrote:

Neither does my unicycle. Nor is it covered in black grease (or any
other sort of grease). There's a small amount of grease sealed
within the pedals, and an even smaller amount sealed within the
cartridge bearings.

The tyre, pedal ends and seat (ie, all extremities) are all black
rubber, so not liable to scratch dig or gouge anything.

...but still containing enough road dirt to be easily able to foul
the clothing of an adjacent passenger, perhaps on their way to a
night out?

Oh, _road_dirt_? You mentioned hardened steel spikes meaning that
well-known sub-class of hardened steel spikes, "road dirt". Or is
"road dirt" a superset of hardened steel spikes? I forget. Whatever.

Road dirt. The stuff that fouls translucent grease and turns it black, as it
does to most of what it comes into contact with, not excluding clothing.

Yep, I agree. Loads more road dirt on pretty much all my rucksacks
than on the unicycle. I'm all for banning road dirt from the
underground.

Everyone must henceforth take off their shoes at the top of the
escalators.

Whatever your views on where the balance should be struck between
the rights of cyclist passengers and the rights of pedestrian
passengers, you *can* see why bikes (and, if appropriate, unicycles)
are banned on the Underground?

I understand some reasons. None of them are to do with hardened steel
spikes, black grease, or for that matter, road dirt.

We must differ on that.