Introduction to Bike Design

Posted by tan xiao yan on

The bike design refers to the ideation and feature of two-wheel, human-powered, pedal-driven vehicles, and their use across various aspects of human’ lives from leisure to sport to basic transportation. The basic parts of the bicycle are composed of 25 parts, including the frame, tire, pedal, brake, chain, etc. All of these are necessary. While among them, the frame is the skeleton of the bicycle, bearing the largest weight of people and goods. According to the operating feature of the parts, it can be divided into guidance system, driving system, braking system:

Guidance system: consist of the handlebar, fork, front axle, front wheel and other components. The rider can change the driving direction and keep the body balance by manipulating the handlebar.

Driving (driving or walking) system: consists of the pedal, middle axle, crank, chain, freewheel, rear axle, rear wheel and other components. The pedal force from a person's foot is driven by a crank, a sprocket, a chain, a free wheel, a rear axle, etc., so as to keep the bicycle moving forward.

Braking system: It is composed of brake components, riders can manipulate the brakes at any time, so that the driving bicycle can be slowed down or stopped, to ensure that the driving safety.

In addition, in order to be safe and beautiful, it also, also fitted with lights, bracket, bell and other components from the practical aspect.



The frame part is the basic structure, the skeleton and also the main body of the bicycle, where the other parts are installed directly or indirectly on. There are many structural forms of the frame, but mainly can be divided into two categories: men's frame and women's frame. Because THE bicycle’s drive relies on the human body's own driving force and cycling skills, the frame becomes the support of the shock load generated in the riding, and also the important structure to make human body’s carry comfortable and safe. The quality of the frame parts manufacturing accuracy will directly affect the safety, stability, and brisk-ride experience. The ordinary spokes are of the equal diameter in order to reduce the gravity, and there are also large in two ends, the small in the middle of diameter spokes, and in order to reduce the air resistance spokes are flat streamline.


It has two kinds: soft-side and hard-side tire. The cross-section of the soft-side tire is wide to wrap the inner tube completely, and larger area touching the ground, suitable for a variety of roads. Hard-side tire weight is light and has small area touching the ground so it is suitable for the flat road to drive, bearing advantages like small resistance, brisk driving and others. The decorative pattern on the tire is designed to increase friction with the ground. The tires of mountain bikes are wider, and the deeper pattern is also suitable for riding on cross-country mountains.


The pedal part is assembled on the left and right crank of the middle axle part, a device turning the flat power into the power. When riding, pedal force firstly is on the pedal parts, and then the pedal axis rotates the crank, chain wheel, middle axle, chain freewheel so that the rear wheel can rotate to make the bicycle forward. Therefore whether the structure and specifications of pedal parts are appropriate or not, will directly affect whether feet position of the cyclists are appropriate or not, the bicycle can be driven smoothly or not.


The front fork part is in the front of the bicycle structure whose upper end is connected with the handlebar part, the frame part cooperates with the front tube while the lower end cooperates with the fore axle component, composing of the bicycle guidance system. It plays a guiding role in the bicycle when turning the handlebar and front fork to make the front wheel change direction. In addition, it can also play a role in controlling cycling.


Chain, also known as block chain or roller chain, installed on the wheel and free wheel. It passes the pedal force from the crank, sprocket to the freewheel and the rear wheel, driving the bicycle forward. Sprocket


made of high-strength steel to ensure that it reaches the required pull.


The screw in the freewheel is screwed to the right end of the rear axle, maintains the same plane with the sprocket, and connects the chain to the sprocket to form the driving system of the bicycle. From the structure can be divided into two categories, single-speed freewheel and multi- speed freewheel. Single- speed freewheel is also known as single sprocket free wheel. Its working principle of single-speed freewheel is: when stepping forward, the chain drives the freewheel forward, at the same time the freewheel internal teeth and screw block contain each other, the turning force from free wheel pass through the core, causing the core drives the rear axle and rear wheel rotating, consequently, the bicycle moves forward. On the basis of a single- speed freewheel, multi- speed freewheel adds a few pieces of the freewheel, combining with the sprocket on the axis to form different transfer ratio, thus changing the speed of the bicycle.


Saddles are based on the preference of riders. The short-distance riders favor the cushioned saddles for their narrower which allow more room for leg swings. The riding position will affect the comfort. With comfort bikes and hybrids, cyclists sit high over the seat, their weight directed down onto the saddle, such that a wider and more cushioned saddle is preferable.


Bicycle brake may be in rim shape, working by the friction pads’ compression against the wheel rims; the hub brakes, where the mechanism is contained within the wheel hub, or disc brakes, pads acting on a rotor additional to the hub.