'ello 'ello 'ello, what's goin' on 'ere then?

I finally got around to commuting in to wok on the bike yesterday, now that the new rules for going around the campus are in place. I did it more out of a sense of obligation for having campaigned for bikes to be allowed on campus and to show my gratitude, than for the sheer pleasure of it (we are in December for goodness sake and it is freezing cold). Still, it was enjoyable and I even managed to go for a run at lunchtime as well.

Just as I was walking to my bike, dressed up to the nines in winter cycling gear, a security guard approached me and asked me the dreaded question "Is that your bike?". I thought, "Here we go"... Oddly enough he asked me if I understood Spanish before I even uttered a word: in the dark and under all my cycling garb I doubt he could have discerned my nationality and we "foreigners" are in the very minority at work. I can only guess that he made a subconscious connection between people mad enough to commute to work on a bicycle in December and "people from the North". In the end he said, "I'm having this problem with my bike: the chain keeps jumping from one cog to another... Can you recommend what I should do to fix it?"...