how much you would like to spend.
10 speed gears or none at all.
These bikes are fun, relaxing and safe and will probably be cheaper than more specialised bikes.
some have suspension like mountain bikes.
These bikes are easy to adjust to suit the rider's needs.
a frame designed for strength rather than lightness.
Mountain bikes or hybrids are also useful for touring, especially if travel includes off-road tracks or gravel roads. There is a trade-off between greater speed and comfort of a standard tourer and off-road handling on a mountain bike.
Racing bikes are designed for speed but are not generally used for commuting because these bikes are vulnerable to potholes or gravel. Racing bikes with advanced technologies can also be expensive.
Mountain bikes usually have suspension for a smoother and faster ride on rough tracks. These bikes are suited to all surface conditions and are increasingly popular for being fun to ride in all weather conditions. Mountain bikes are good for commuting and are available in a wide range of prices. Mass-produced basic models are relatively cheap. Racing mountain bikes with full suspension can be expensive.
Bicycle motocross bikes are designed for specialised racing and performing tricks. Many people assume bicycle motocross are children's bikes but these bikes can be enjoyed by adults. The bikes generally come in two sizes: 500 mm (20 inch) wheels and 600 mm (24 inch) wheels.
Bicycle motocross bikes are not the best bikes for commuting. The low seat position means that riding long distances can be uncomfortable and the absence of gears makes hills difficult to negotiate. Like mountain bikes, basic mass-produced models can be inexpensive and top-of-the-range models are relatively costly.
Folding bikes are good for commuting as these bikes are easy to store and transport. Many fit in a conventional suitcase and are able to be carried onto trains.
The range of folding bikes is growing and there are bikes suitable for commuting or use on road, off road or for racing. Folding bikes can be slightly more expensive than an equivalent non-folding model but the added convenience can make these bikes good value.
back, shoulders and neck support.
The disadvantages of recumbents include poor visibility in heavy traffic, being too close to exhausts and the undersides of trucks, and be expensive as these bikes are not manufactured in large numbers.
Tandems help people share the joy (and effort) of cycling. The two riders on a tandem create about the same air resistance as one rider but have twice the strength to overcome it. These bikes can be ridden with less effort (or faster with the same effort) compared to one-person bikes. Tandems are excellent for general road use and touring.
Tricycles are available for children and adults and can be either ridden as a recreational or transport vehicle. The large step-through frame and wide rear seat make these bikes popular with people who have balance or mobility difficulties and provide a safe way to exercise.
Bicycles can be as innovative and weird as your imagination. Bicycle machines are usually built by enthusiasts or specialised frame builders. Some important innovations used in mainstream bicycles have come from experimenting.
Fit is important as it determines the level of safety and comfort. Bike frames come in different sizes and seats and handlebars can be changed or adjusted to size.
The following section discusses choosing the correct size bike for adults. The rules for children's bikes are slightly different.
Ensure a comfortable clearance between the top bar and your crotch when you straddle the frame – 25 to 50 mm (1 to 2 inches) on a road bike and 40 to 100 mm (1.6 to 4 inches) on a mountain bike. The distance is larger for mountain bikes because of the triangle shaped frame. When the bike does not have a top bar, you can estimate where the bar would go – just below where the adjustable seat post meets the tube.
Adjusting the seat height is easy and crucial to comfortable pedalling.
Your leg should be just less than fully extended at the bottom of the stroke.
Ensure you are not tilting your hips side to side to reach.
For comfort, most people find that the seat itself should be level or very slightly upturned.
The choice of handlebar height depends on the type of riding you usually do and personal preference. Lower handlebars put you in a crouching position that gives less wind resistance and the ability to apply more power to the pedals. This however can create strain on your back and neck. Higher handlebars put you in a more upright position, recommended for comfort, seeing and being seen. Most people find riding in a more upright position puts less strain on their back and neck. You might need to change the head stem to modify the handlebar height.
Frame size and seat height are the major considerations in getting a bike to fit. Bikes are designed so that once these are correct, the bike will be a good fit for the average rider.
Some riders will continue to experience discomfort after standard adjustments are made due to body proportions or riding style. Finer adjustments can be made by adjusting the seat forward and backward. To adjust the handlebars forward or backward you will probably need to buy a new head stem.
It is better to have your bike retailer supply the right size bike for the rider rather than trying to modify the bicycle to suit the rider.