5 things every urban cyclist must carry

I'm very bad at heeding my own advice. I've been caught. I've been stranded. I hereby vow to never again leave my house on a bicycle without these five items:

1. Spare inner tube of appropriate size (If you switch bags and bicycles, this is crucially important. If you have multiple bikes, attach a tube to each using a small under-seat pack), tire levers and a working bicycle pump.
2. An emergency clothing layer. A windbreaker doesn't seem like much, but it will make a huge difference if you're heading into that north-west Chicago wind, as I often do on my way home.
3. Food. Especially if you are susceptible to those nasty blood sugar fluctuations. I find most energy bars unpalatable, but if you can stand them they are the most packable. I bring nuts (when I don't forget, that is).
   

   

   
   
4. Your bike lock AND KEY!
5. Extra carrying capacity. When I decide to "travel light", that's usually when I wind up finding something great to bring home. Even a bunji strap will do it. A collapsible pannier is even better.

And, finally, emergency cash, in case you forget any of the above.