On Tue, 30 Sep 2014 18:42:10 +0100
Mrcheerful wrote:

That would all depend upon having a nice even level road.

Or a nice knobbly mountain bike.

In the
event of disaster neither of those are likely, whereas feet can climb
over things very easily and going up hill (necessary to escape tidal
waves ) is quite natural and simple on foot. I would imagine that
poor quality knee joints are not too hot for cycling in any case.

Actually my knees work quite well on a bike because their movement is
constrained by the pedals, so they tend not try to twist out of
alignment, which they can do when I'm walking, particularly on uneven
ground.