Bicycle Frame
For a bicycle to carry an average fully grown adult (130-180lbs), the bicycle needs to be sturdy. The bicycle needs to be able to support someone on top of it without snapping or breaking. To do that, the bicycle is made of mostly inexpensive steel rods filled with air or lighter alloys based off of steel or aluminum. The specific shape of the bicycle usually two triangles shaped to make a diamond is specifically used to distribute weight across the bike. The bicycle is designed to be slightly flexible in order to absorb shock and make the ride more comfortable.
Braking System
The braking system in a bicycle works because of friction. When you pull the brakes, rubber pads clamp onto the wheel and turns the kinetic energy when you move into thermal energy, decreasing kinetic energy, until you stop.
https://www.pexels.com/photo/wall-sport-green-bike-2242/
Article Page: http://www.explainthatstuff.com/bicycles.html
Video for Bicycle Gears
