Anatomy of a Mountain Bike

Fig.1 Anatomy of Mountain Bike (Image by Wikimedia Commons)

The bike is a simple and cheap mean for transportation and leisure. It is used from people of all ages and genders. The design is very simple compromised by 2 triangles that make the frame, a set of 2 wheels and a fork. It also has a seat and a handlebar for steering. All these are shown in more detail Fig. 1.

Despite of the simplicity in the design they are many complicated mechanics that have to work together so that the bikes moves efficiently. The bike parts are essential in understanding the bike, how it moves and what needs to be done to improve the experience. Every amateur cyclist should know these parts.

The purpose of these parts is summarized below:

Static Parts

These parts physically create the bike but do not enable it to move.

Frame: The frame is made of 2 triangles attached to each other. Each triangle line (called tube) has a specific name as seen in the picture above. These triangles have specific angles depending on the type of bike (road, MTB etc) and its intended use (racing, leisure). The angles and the length of the tubes are generally referred to as bike geometry.

Fork: An arch with a vertical tube at the top to attach to the head tube and handlebar. There are 2 types of forks. Suspension and stationary.  Both have the same task of securing the front wheel and steering the bike. The difference is mainly on the type of cycling they are intended (road, off-road).

Wheels: These are the only parts of the bike that touch the ground. They are 2 circles(rims) that have rubber tires attached to them and they connect to the fork and the rear triangle. The rims have spokes attach to them that extent to the center of the circle and attach to a device called the Hub. The rear wheel has a cassette attach on the Hub.

Seat post and Sate: Seat post is connected to the middle of the frame and is a height adjustable tube to regulate different heights of people. The seat is attached to the seat post and it is simply a seat for the cyclist

Handlebar: This part is a piece of metal, flat or curved, depending on the type of bike that is used for steering. It accommodates the shifters and the brake levels.

Drive train:

These parts enable the bike to move when force is applied to them

Crankset: Consist of chainrings, cranks and pedals and it is attached to the center of the frame at the bottom part below the seat post. Cranksets can have one, two or three chainrings. The cyclist applies pressure to the pedals in a clockwise direction for the bike to start moving.

Chain: A set of links that transfer power from the cyclist to the bike. The chain connect the crankset to the rear cassette/wheel combination

Cassette: A set of sprockets that are attached to the rear wheel. This is the part that the chain is attached to. Their use is to offer heavier or lighter gears to the cyclist.

Derailler Front/rear: Mechanical parts that are controlled by the shifters to change the position of the chain either on the chainrings or the sprockets. This function offers the cyclist ‘lighter’ or ‘heavier’ gears

Shifters: Shifting levels attached to the handlebar and control the derailleur’s via a steel cable.

Brakes: Disk or Rim brakes are mechanical parts that are used to stop the bike by applying friction either to a disk or the wheel rim

Brake levels: Control the brakes either via a steel cable or by a hydraulic system

The above summary should give a basic understanding of a bike and demystify what more experienced cyclists are talking about at their coffee brakes.

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Coach Chris

UCI Level 2 Coach
CCF certified instructor