How to choose a bicycle?

To figure out how to choose which type of bike is best for you, ask yourself where and how often you plan to ride, what you will use your bike for, and how much you are willing to invest. 

Get to know the different types of bikes

 There are many different types of bikes that offer a wide range of capabilities. If you live in a city, you probably want a bike that’s built for roads. If you live somewhere where you can bike on trails, then a mountain bike might be more your speed. Here, we will mostly consider the widely used 3 categories of bikes - Hybrid, mountain bike (MTB) and roadies.

• Choose a mountain bike if you like going over large bumps and dirt. Many mountain bikes have at least a front suspension to improve comfort and steering control on rough surfaces. Mountain bikes can also be good for general urban riding, due to stability and for going over curbs and the like. Beginners may find mountain bike handlebars and controls easier to use.
• Choose a road or touring bike if you’re riding on mostly flat roads and terrain. These bikes typically have drop handlebars that allow for several hand positions and postures. Touring bikes provide more comfort if you plan on carrying a lot with you because these bikes are outfitted with the necessary mounting bolts for cargo. Touring and road bikes also offer different gears which help you change resistance if you encounter a hill or strong winds.
• Hybrid bikes are good if you find more comfort in sitting upright and want a more padded saddle. Tires on hybrid bikes are wider and more durable than both road and touring bikes, and can be ridden on different terrains with ease. 

Bike Fit to consider

  The fit of the bike is essential to consider. Different bikes have different dimensions for varying body types. Make sure the saddle height isn't too high for you. Mounting and dismounting should be comfortable and easy. 

• Make sure you have a good reach to the handlebars. When gripping the handlebars, you want a slight bend in your elbow. You should be able to easily grip your handlebars without having to bend over too much, even on road or racing bikes. When riding you want to be able to keep your head up without straining your neck. If you’re reaching too far forward and looking at the ground, your handlebars are too far away from your seat.
• Frame size and seat height will affect comfort as well. Look for a bike that you can easily adjust the seat height on. You should be able to easily touch your feet on the ground and maintain control over your bike.
• While you can make adjustments to most bikes, you want to look for one that provides you with a good saddle position. You want your knee to be directly above the ball of your foot when your pedal is in the 3 o’clock position. This will provide consistent movement and make it easier on your knees.
• Check wheel size. Bikes come equipped with tires from 12" for children's bikes, up to a standard 26 or 28 inch (66.0 or 71.1 cm), for adults, and even higher for specialized racing bikes. Larger wheels may improve your speed, but if your wheels are too large for your body, riding will be more difficult.

 Test ride a bike before you buy it. If you can't get the bike shop to let you try a bike out, go to another shop, or borrow one from a friend. It is easier to get a bike that fits than to adjust and get acclimated to one that doesn't.

• Ride the bike around the block to get a good feel for it. You should feel comfortable and in control at all times. Make sure you can easily reach the handlebars and all the components, like shifters and brakes.
• Test the gears and brakes. See how easy it is for you to shift gears and brake quickly. The bike should be responsive and shouldn’t take too much effort to adjust gears or brake.
• Practice turning corners. You want to be comfortable with maneuverability. Some bikes are lighter than others and require more precision when maneuvering. If you don’t feel comfortable on the bike, try out other ones to find something that feels natural.

 Test the weight and materials. No matter the type of bike, there are different weights and materials in every one.

• If you’re looking at a mountain bike, ask about the frame weight and how it affects performance. Though mountain bikes will typically be heavier than road bikes, you may find that for you, a heavier one will be harder to operate on the terrain. Check out the quality of the suspension. Full suspension mountain bikes are meant for serious off-road riders. You may not need the best suspension of you’re not solely riding over extremely rough terrain.
• Road bikes and touring bikes offer a lot of options in the way of frames and frame construction. The more performance-based options might use a carbon frame. Carbon is a very lightweight material that helps with performance and speed. However, carbon frames can be more expensive. The material and shape of your frame can affect your comfort and speed, but might not be necessary for your type of riding. While carbon is popular for its lightweight nature, it’s easily damaged. Aluminum frames may be heavier, but are more durable and often less expensive. 
• Get a bike with the right tires for your needs. Thinner tires, often on road bikes, are fast and lightweight. However, thinner tires aren’t good on rocky terrain and puncture easily. Touring bikes have slightly thicker tires with more tread, which allows for more versatility in terrain. The tread also helps grip on wet or slippery roads.

References : wikiHow.com