He's finally reached the end of the D.E.N.N.I.S. System and is trying to Separate Entirely

As an added note, eggs with a spot of blood are forbidden by the laws of Kashrut, if I recall correctly.

How unreasonable is the lack of bikes? Presuming that the production of new inner-tube tires is impossible, how long would bike tires last before being destroyed? Is it possible that there were bikes, but people stopped using them as they became too much of a headache to repair and maintain?