Riding to the office this morning, change lanes to pass a slow moving car, go to shift up into the next gear and nothing. Hmm, me thinks, foot must have slipped on the wet gear lever - try to feel for the lever with my foot but still nothing. Okay getting a little worried now so take a quick glance down to see what the problem is. Ahh there's the gear lever, dragging along the road hanging by the linkage mechanism, great. Managed to pull over to the side of the road to inspect the problem - seems the bolt holding the mechanism to the frame had decided to work itself loose. Thinking back I remember succesfully changing gears only a couple of block backs so start walking back in search of the wayward part. Fortunately I was able to find it and put everything back together but made me realise perhaps I should be checking the tightness of such things a little more often.