Bike Parts

Bicycles can be relatively simple, or very complex depending on the variety. Here is an overview of the many different parts that make up your bicycle.

Drivetrain and Gearing

The drivetrain includes the pieces of the bike that propel the bike forward. It includes the pedals, cranks, chainrings, chain, sprockets and derailleurs. The pedals are attached to a set of cranks. The cranks rotate a chainring which causes a chain to transmit power to the rear wheel. Sprockets are found on the rear wheel and push the bike forward. The derailleurs are used to allow you to switch gears, or change the ratio of pedal strokes to rotations of the rear wheel.

The derailleur system normally consists of two derailleurs. The front derailleur is used to select the chainring. The rear derailleur selects the appropriate sprocket. Most bikes have two or three chainrings, and between 5 and 11 sprockets on the rear wheel. The number of gears on your bike can be calculated by multiplying the number of chainrings by the number of sprockets. For functionality purposes, many gears overlap or require the chain to run diagonally, so the number of usable gears will be fewer.

Different gears and ranges of gears are appropriate for different people and styles of cycling. Since your legs are most efficient over a narrow range of pedaling speeds, having a variety of gear options will help you to maintain an optimum pedaling speed while covering various types of terrain. You'll want to select your gear based on the circumstances in which you are biking. Ideally you would use a high gear when going downhill, a medium gear when biking on a flat road, and a low gear when going uphill or against strong winds.

Steering and Seating

Handlebars are used to turn the fork and the front wheel. Three styles of handlebar are common. Upright handlebars curve gently back toward you offering a natural grip and comfortable upright riding position. These are usually found on leisure bikes such as cruisers. Road bikes typically feature drop handlebars. This type curves forward and downward, allowing you to ride in a more aerodynamic crouched position. You can also choose to ride in a more upright position thanks to the upper flat sections found on this type of handlebar. Mountain bikes generally feature a straight handlebar that sweeps slightly backwards and upwards. These handlebars usually have wider widths which gives you increased leverage against the wheel and can provide better handling.

Saddles also vary with rider preference. If you are looking for comfort, cushioned saddles are a lot softer and wider. These are often found on bikes such as cruisers and hybrids. For racing bikes, narrower and harder saddles are usually what you'll find. These allow more room for your legs to swing and are more efficient overall.


Different types of brakes are available for your biking needs. Rim brakes use friction pads that compressed against your wheel rims to slow the bike down. Internal hub brakes use friction pads that are contained within the wheel hubs. Disc brakes use a separate rotor for braking. These are more common for mountain bikes than road bikes, due to the fact that they are heavier.

Most bikes use hand-operated brake systems. Force is applied to brake levers found on the handlebars and transmitted via cables or hydraulic lines to the friction pads, which apply pressure to the braking surface that slows the bike down. Internal hub brakes may be either hand-operated or pedal-actuated.


Suspensions serve two purposes: keeping the wheels in contact with the ground which will help improve your control, and improving comfort by isolating you as a rider from jarring due to rough surfaces. Bicycle suspensions are used primarily on mountain bicycles due to the rough terrain where these bikes are typically used. They also common on hybrid bicycles and recumbent bicycles. Road bicycles tend to have no suspension.

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