A road bike, is a bicycle designed for competitive and leisure cycling on the road. Road bikes used for racing will traditionally have a more aggressive riding position and will be considerably lighter than other road bikes. The most important characteristics about a road bike are its weight and stiffness which determine the efficiency at which the power from a rider's pedal strokes can be transferred to the drive-train and subsequently to its wheels. The drop handle bars are positioned lower than the saddle in order to put the rider in a more aerodynamic posture. The front and back wheels are close together so the bicycle has quick handling. The gear ratios are closely spaced so that the rider can pedal at their optimum cadence.
Time Trial Bike
A Time Trial bike, often known as a TT bike is built purely for speed. The riding position is optimized for aerodynamics and ultimately speed, often resulting in reduced rider comfort. A TT bike will be ridden on the road in either an individual timed effort or as part of a team, known as a team trial (TTT). To improve aerodynamics, a TT bike will often be ridden with a disk wheel on the back and a 3 or 5 spoked carbon fiber front wheel.
MTB / Downhill
A mountain bike (abbreviated MTB or ATB, for all-terrain bicycle) is a bike created for off-road cycling. Mountain bikes are typically ridden on mountain trails, canal towpaths, single tracks and other unpaved environments. These types of terrain commonly include rocks, washouts, ruts, loose sand, as well as obstacles such as logs, vertical drop offs, and smaller boulders. Mountain bike construction differs from a typical bicycle in many ways. The most noticeable differences are the inclusion of suspension on the frame and fork, larger tires and more durable heavy duty wheels, more powerful brakes, and lower gear ratios needed for steep grades with poor traction.
Downhill mountain biking (DH) is a genre of mountain biking practiced on steep, rough terrain that often features jumps, drops, rock gardens and other obstacles. Downhill bikes are heavier and stronger than other mountain bikes and feature front and rear suspension with over 8 inches (200mm) or (20cm) of travel, to glide quickly over rocks and tree roots.
Hybrid bikes blend characteristics from more specialized road bikes, touring bikes and mountain bikes. The resulting "hybrid" is a general purpose bike that can tolerate a wide range of riding conditions and applications. Their stability, comfort and ease of use make them popular with novice cyclists, casual riders, commuters, and children. Hybrids typically borrow the flat, straight handlebars and upright seating posture of a mountain bike, which many cyclists find comfortable and intuitive. Hybrids also employ the lighter weight, thinner wheels and smooth tires of road bikes, allowing for greater speed and less exertion when riding on the road. Hybrid bikes often have places to mount racks and bags for transporting belongings, much like a touring bike.
Similar to the commuter bike, the city bike is optimized for urban commuting. The city bike has mountain bike heritage, gearing, and strong yet lightweight frame construction it usually features mountain bike-sized (26-inch or 660 mm) wheels, a more upright seating position, and fairly wide 38–50 mm heavy belted tires designed to withstand road hazards commonly found in the city, such as broken glass. Using a sturdy welded chrome or aluminum frame derived from the mountain bike, the city bike is more capable at handling urban hazards such as deep potholes, drainage grates, and jumps off city curbs. City bikes are designed to have reasonably quick, yet solid and predictable handling, and are normally fitted with full fenders for use in all weather conditions. A few city bikes may have enclosed chain guards, others may have suspension forks, similar to mountain bikes. City bikes may also come with front and rear lighting systems for use at night or in bad weather.
A BMX bike is an off-road sport bicycle used for racing and stunt riding. BMX means bicyclemotocross. Though originally denoting a bicycle intended for BMX Racing, the term "BMX bike" is now used to encompass race bikes, as well as those used for the dirt, park, street, flatland and BMX freestyle disciplines of BMX. BMX frames are made of various types o of steel and aluminum. The introduction and widespread popularity of the cassette hub has ushered in the use of smaller gearing on BMX bikes. Advantages of smaller gearing hubs include lighter weight, and more clearance when grinding. The free wheel hub is all but extinct due to several factors. The smallest freewheels that can be made is with 8 teeth, which is smaller than most riders prefer. Also, they are less consistent than cassette hubs, and skip or jam up far more frequently. On most freestyle, street, and park BMX bikes, the wheels have 36 spokes. Race bike wheels also usually have 36 spokes and bike wheels vary in size, from 16" to 26", with 20" being the most popular.