Glossary of Bike Terms

BikeParts-44

Aftermarket: Parts or accessories not supplied from the original bicycle manufacture.

Araya wheels: Japan’s leading bicycle wheel manufacturer. Araya’s wheels are very well made, and considered one of the best on the market.

Bottom Bracket: The bearings and spindle, located in the lowest part of the frame, to which the crank is connected.

Center-pull Brake: A brake in which the main cable runs down the center line of braking device and pulls the pressure from the center of the brake. This type of brake was popular from the late 1960’s to the early 1980’s. Center-pull brakes are a good choice for bicycles that have a long reach from the mounting point to the rim.

Chain: Modern bicycles use a roller chain to connect the crank to the rear drive wheel. Chain drives are among the most efficient means of power transmission known.

Chain Guard: Any of several types of protective baffle device used to prevent the bicycle chain from entrapping a riders pants leg, or soiling the cyclist’s leg or clothing. Getting your clothing (mostly a pants leg) caught in a bicycle chain can be an inconvenience on any bike, and in some cases very dangerous.

Coaster Brake: A type of rear bicycle hub that incorporates an internal brake which is operated by the rider pedaling or pushing backwards. Called a “coaster brake” because it combines the functions of the brake and freewheel (“coaster”) in a single unit. Bicycles equipped with coaster brakes will have an external lever, attached to the left side of the rear hub, extending to a frame mount, as noted in the photo below.

Crank: The arm which connects the pedals to the bottom bracket axle. Sometimes called a “crank arm.” In simple terms, the crank is used to turn the front sprocket and power the chain to the rear wheel.

1 -piece Crank: A one-piece crank consists of a single steel forging axle-type device which allows the bicycle rider to turn the chain and propel the bike. Installed through the frame and connected to the front sprocket. One piece cranks are commonly found on older American made bicycles, and many current low-end bikes.

3 -piece Crank: Nowadays many bicycles are equipped with a three-piece crank. A three-piece type crank consists of three pieces; the left arm crank, the center axle, and the right arm crank. Installed into the frame and connected to the front sprocket, three-piece cranks use either cotters or tapered cotterless attachments. Generally much stronger than a one-piece crank, the three-piece is also more expensive to produce.

Derailleur: The assembly or mechanism that “derails” or moves the bicycle chain from one sprocket to another, in order to change gears. The derailleur is operated by a cable.

Dia-Compe brakes: Once the leading Japanese bicycle brake manufacture. Countless bicycle manufactures have used Dia-Compe brakes. The company has a reputation for being of high-quality.

Fork or Forks: Usually referring to the front fork, the part of the frame-set that houses the front wheel and or fender. The fork is attached to the main bicycle frame and consists of the two blades (most are round, some flat) that travel downward to hold the the front axle, and allow the rider to steer.

Fixed-Gear or “Fixie”: A rear drive system that lacks a freewheel, meaning you can’t coast without the crank turning. There usually is only a single gear ratio.

Frame: The skeleton of a bicycle to which the wheels and most other parts are connected. Frame below includes the forks.

Frame size: The height of the bicycle based on measuring the size of the seat post tube.

Hand brake: A brake that slows the bike via hand pressure or squeezing a lever attached to the handlebars.

Handlebar or Handlebars: Handlebars are the wide (mostly) chrome tubes that attach to the top of the forks allowing the rider to turn the bicycle.

Kickstand: A steel prop for holding a bicycle upright while parked. They are called “kickstands” because they are operated by the foot.

Lug or Lugged (frame): A short angled tube used to join and reinforce two or more tubes of a bicycle frame. Generally known to improve the overall strength of the bike frame as a unit. Can also be a bit stylish is appearance.

Pedal or Pedals: Connected to the crank arms, the pedal is the part you put your foot on. The axles of the pedals are threaded into the crank.

Quick-release lever: A single lever used on seat posts and some wheel hubs, which replaces the locknut for quick and easy, no-tool removal or adjustment.

Saddle: A bicycle seat, sometimes referred to as a saddle.

Safety Levers: Shortly after the American introduction of the road bike, Dia-Compe invented a bolt-on extension that allowed the bicycle (hand) brake levers to be operated from the top and middle of the handlebars. These levers made it much easier for riders to brake while holding the handlebars in a more comfortable up-right riding position. Soon, nearly every bicycle manufacture around the world offered safety levers on all of their road bikes.

Seat Post: The removable and adjustable (sometimes chrome) tube that the saddle mounts onto.

Seat Tube: The frame tube that connects between the top tube and the bottom bracket. The seat post inserts into the top of the seat tube.

Single-Speed: While any bike that doesn’t have multiple gears or speeds is technically called a “single-speed” bicycle, this term generally refers to a bike with a one-speed freewheel and coaster brakes.

Spoke or Spokes: One of the wires connecting the outside wheel to the hub of a bicycle. A conventional spoke has a head, appearing somewhat like the head of a nail, to keep it from pulling through the bicycle hub. On the other end the spoke is threaded, and a special adjusting nut is attached and fits through the wheel.

Twenty-four (24) inch: These terms are frequently used to help describe a bicycle size, but they do not refer to the frame size, they instead tell the bicycle wheel size or diameter. There are many different tire sizes that can be mounted on these wheels.

Twenty-six (26) inch: These terms are frequently used to help describe a bicycle size, but they do not refer to the frame size, they instead tell the bicycle wheel size or diameter. There are many different tire sizes that can be mounted on these wheels.

Twenty-seven (27) inch: These terms are frequently used to help describe a bicycle size, but they do not refer to the frame size, they instead tell the bicycle wheel size or diameter. There are many different tire sizes that can be mounted on these wheels.