Change and a $20 bill: In case your cell phone’s battery dies, it’s nice to still be able to use a payphone if you need to. Also, the $20 is a great thing to have in case you lose your wallet or have some other mishap. I’d rather be able to sit in a coffee shop or fast food restaurant when it starts raining while I’m waiting for my friend or cab ride, and a hot cup of tea or coffee or the beverage of your choice and a snack makes it all the more pleasant. Just try to remember, this is for emergencies, and if you use it, replace it ASAP!
Any bike that gets ridden seriously as transportation or on long rides needs at least a basic tool/emergency kit, and the knowledge to use it, unless the rider is always in a position to call a friend with a car or a cab when their bike needs a quick fix on the road. If you never travel more than a few miles, this can be overkill, and calling a friend or a cab may be just the ticket, but if you want to be more self reliant, this is something you should seriously consider. This list may sound like an awful lot of stuff to carry, but really, it only weighs a few lbs and fits in a small, under-seat bag that comes off quickly so I don’t have to leave it with the bike if theft is a concern. If you always carry a regular rack top bag, you can also just put all this in a small nylon bag and throw it in there, but I prefer an under-seat bag.
I bought this book to supplement "Anybody's Bike Book" because I always like to get a second opinion. This book uses photos extensively rather than drawings as in the other book. They are well composed and quite helpful providing additional detailed information in a clear, conciseful manner. Information is provided in heirarchy format and geared from initial purchase to daily maintenance of my two wheeled friend. Good book!
Whether you ride a single, 7, or 10 speed bike or anything in between, you will need a slightly different chain. The major difference is that they come in varying widths to accomodate the different spaces between the gears, but quality of construction is also a factor in choosing a chain. Inspecing the chain should be a part of your regular cycle maintenance procedure- It’s important to keep a chain well lubricated, but oil will also attract dirt and so different oils for specific riding conditions are available. Remember to clean your chain regularly to get the longest life out of it and the gears.