A bicycle, also called a pedal cycle, bike, push-bike or cycle, is a human-powered or motor-powered assisted, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A bicycle rider is called a cyclist, or bicyclist.
A tandem bicycle or twin is a form of bicycle designed to be ridden by more than one person. The term tandem refers to the seating arrangement, not the number of riders. Patents related to tandem bicycles date from the mid 1880s. Tandems can reach higher speeds than the same riders on single bicycles, and tandem bicycle racing exists. As with bicycles for single riders, there are many variations that have been developed over the years.
A bicycle wheel is a wheel, most commonly a wire wheel, designed for a bicycle. A pair is often called a wheelset, especially in the context of ready built "off the shelf" performance-oriented wheels.
A derailleur is a variable-ratio bicycle gearing system consisting of a chain, multiple sprockets of different sizes, and a mechanism to move the chain from one sprocket to another.
A touring bicycle is a bicycle designed or modified to handle bicycle touring. To make the bikes sufficiently robust, comfortable and capable of carrying heavy loads, special features may include a long wheelbase, frame materials that favor flexibility over rigidity, heavy duty wheels, and multiple mounting points.
A trailer is an unpowered vehicle towed by a powered vehicle. It is commonly used for the transport of goods and materials.
A sprocket, sprocket-wheel or chainwheel is a profiled wheel with teeth that mesh with a chain, track or other perforated or indented material. The name 'sprocket' applies generally to any wheel upon which radial projections engage a chain passing over it. It is distinguished from a gear in that sprockets are never meshed together directly, and differs from a pulley in that sprockets have teeth and pulleys are smooth except for timing pulleys used with toothed belts.
A bicycle fork is the part of a bicycle that holds the front wheel.
A single-speed bicycle is a type of bicycle with a single gear ratio. These bicycles are without derailleur gears, hub gearing or other methods for varying the gear ratio of the bicycle.
A fork end, fork-end, or forkend is a slot in a bicycle frame or bicycle fork where the axle of a bicycle wheel is attached. A dropout is a type of fork end that allows the rear wheel to be removed without first derailing the chain.
On a bicycle, the cassette or cluster is the set of multiple sprockets that attaches to the hub on the rear wheel. A cogset works with a rear derailleur to provide multiple gear ratios to the rider. Cassettes come in two varieties, freewheels or cassettes, of which cassettes are a newer development. Although cassettes and freewheels perform the same function and look almost the same when installed, they have important mechanical differences and are not interchangeable.
A freehub is a type of bicycle hub that incorporates a ratcheting mechanism.
A tow hitch is a device attached to the chassis of a vehicle for towing, or a towbar to an aircraft nose gear. It can take the form of a tow ball to allow swiveling and articulation of a trailer, or a tow pin, or a tow hook with a trailer loop, often used for large or agricultural vehicles where slack in the pivot pin allows similar movements. Another category is the towing pintle used on military vehicles worldwide.
A bicycle trailer is a motorless wheeled frame with a hitch system for transporting cargo by bicycle. It can greatly increase a bike's cargo capacity, allowing point-to-point haulage of objects up to 4 cubic yards in volume that weigh as much as half a ton.
A rowbike is an example of a rowing cycle, hybrid fitness/transport machine that combines a bicycle, and a rowing machine. "Rowbike" is a trademark of the Rowbike company. The Rowbike was invented by Scott Olson, the creator of Rollerblade inline skates. "Rowling" is a combination of rowing and rolling, and is sometimes used in place of rowing when describing a Rowbike.
A belt-driven bicycle is a chainless bicycle that uses a toothed synchronous belt to transmit power from the pedals to the wheel.
The following outline is provided as an overview of and topical guide to bicycles:
A quick release skewer is a mechanism for attaching a wheel to a bicycle. It consists of a rod threaded on one end and with a lever operated cam assembly on the other. The rod is inserted into the hollow axle of the wheel, a special nut is threaded on, and the lever is closed to tighten the cam and secure the wheel to the fork. Wheels equipped with quick release mechanisms can be removed from the bicycle frame and replaced without using tools by opening and closing the cam lever, thus more quickly than wheels with solid axles and nuts. On the negative side, a quick-release hub renders a wheel more vulnerable to theft and care must be taken to ensure that the mechanism is properly tightened.
