noun, noun phrase
The arm of the crankset that connects the chainring to the bottom bracket.
Example usage: The chain was rubbing against the crank arm on my mountain bike.
Most used in: Mountain biking and road cycling.
Most used by: Cyclists who are familiar with the parts of a bicycle.
Comedy Value: 2/10
What is a Crank Arm?
A crank arm is a cylindrical rod that transmits power from the cyclist’s legs to the chainring. It is one of the major components of a bicycle drivetrain. It is connected to the bottom bracket axle and the chainring.
Crank arms come in various lengths, ranging from 165mm to 180mm. The length of the crank arm is determined by the type of bike, the rider’s style, and the rider’s height. For example, a mountain bike rider may need a shorter crank arm than a road cyclist, while a taller rider may need a longer one. Generally, shorter crank arms are better suited for climbing and longer crank arms are better for descending.
Crank arms are typically made from aluminum or carbon fiber. Aluminum is the most common material used for crank arms due to its affordability and durability. Carbon fiber is lighter and stiffer, but is more expensive and less durable than aluminum. The type of material used for an individual’s crank arm will depend on their budget and riding style.
The average weight of a crank arm is approximately 150-200 grams, depending on the material used and the length of the arm. The weight of the crank arm is an important consideration for riders who are looking to minimize the overall weight of their bike..
The Origin of the Cycling Term 'Crank Arm'
The term 'Crank Arm' is commonly used by cyclists to refer to the arm attached to the pedal axle on a bicycle. The term is believed to have originated in the late 1800s in England and France, when the crank arm was first used on bicycles.
The first crank arms were made from metal, typically steel or iron, and were designed to provide riders with a more efficient way to propel the bicycle forward. The crank arm was used to transfer the rider's pedaling motion to the rear wheel, allowing the bicycle to move faster and more efficiently.
Today, modern crank arms are typically made from lightweight aluminum or carbon fiber, and come in a variety of sizes and shapes. The crank arm is one of the most important components of a bicycle and is essential for providing riders with efficient power transfer and performance.