As you could probably guess, your bicycle will be one of the most important pieces of gear you will need for your trip. I'm not saying you need the most expensive top of the line bike though. With how easy it is to find information on the internet nowadays, it is very easy to get stuck in the trap of over thinking what you need. If you venture to any web site where enthusiasts hang out you'll quickly start to think you need top of the line everything to survive. This is nowhere near true though. People have been riding long distances by bicycle for ages now and used whatever they had on hand. I know of one guy out there on the road recently who was crossing the country on a department store bicycle and was making good headway. If you can afford a brand new Surly Long Haul Trucker, Trek 520, Fuji Touring, etc. I highly recommend investing in one. A bike set up for touring will make your journey so much easier on your body. If you can't afford a brand new bike, it's time to hit up garage sales and craigslist or make do with what you have. Here are some simple guidelines for what will make your life easier:
- Good fit. Having a bike that fits you properly is probably the most crucial thing to look for in a bike. A bike that is not the right fit for you will start to give you pain in your hands, back, shoulders, etc. in no time, especially when you are doing 50+ miles a day. You can search online for the guidelines on what is a good fit (REI has a pretty good short video on it here) You can also have your local bicycle shop do some measurements on you to find what you need. Bicycle shops run on very low margin though, so if you don't buy a bicycle from them please go back to them for service or buying accessories so we can help support local business.
- Gearing. If you will be riding up any hills at all you will want a bike with a triple chain ring (The sprockets up front). I myself did not heed this advice and climbing hills was gruesome at times. I could just imagine if I were riding in mountainous terrain.
- Braze-ons for accessories. If your bike did not come outfitted with fenders and racks you're going to need them. The fenders will help to keep you dry in the wet and the racks will give you a place to strap your panniers and other stuff to. To add these accessories though, your bike is going to need to have the bolt holes (braze-ons) to attach them with.
- Multiple hand positions. When riding long distance you're going to want a bike that has handlebars with multiple places to put your hands. This will allow you to switch up your stance as you are riding for different comfort levels
- Wide Tires:This is something I wish I had thought about more. I took off on my first trip on standard road bike 700x23 skinny tires. Although they may roll a lot quicker, you have to be super careful with every pothole, rock, storm drain etc. Also you can not ride over bridges with metal grating. Get yourself some wide tires.
For more information on buying a bicycle please check out this other great Instructable http://www.instructables.com/id/Buying-used-bikes-for-beginners/