Not everybody learns to ride a bicycle on training wheels. And if you are someone who didn't, you might be overwhelmed when looking into making a new bike purchase. If you are a beginner adult looking to purchase a bicycle, you'll want to make sure you end up with the right size bike and a type that fits your needs.
Decide what kind of riding you will be doing most. If you are interested in doing distance trips, a road bike might be right for you. A mountain bike works best for off-road trails. If you are looking for a way to get around town, a hybrid bike or an urban bike are likely better fits. The weight of the frame, types of tires, handlebars and suspensions are the main things that can vary between types of bikes.
Check that the bike fits you. The easiest way to get an idea of what size you need is to stand over the bike, straddling the frame. You should be able to stand comfortably with at least 1 inch of clearance for road bikes and closer to 2 to 4 inches for mountain bikes. If possible, take the bike for a quick spin to make sure your legs feel comfortable on the pedals and your arms are comfortable on the handlebars. Both your arms and legs should have a slight bend when stationary. Women and shorter men can take advantage of women-specific designs.
Pick a bike in your price range. If you are a beginner, chances are you will not need a top-of-the-line model and should start with something more affordable. This way, you can make sure you find a type of bike that works for you without breaking the bank. Decent beginner bicycles normally cost a few hundred dollars, but premium bikes can easily run over $2,000.
Consult with specialists at an independent bike retailer to find a bike that fits your size and cycling needs.