What does a gear look like? (GIF)

For every one rotation of Gear A, Gear B rotates twice. This means the gear ratio of this gear is 1:2

Gear ratios (Part 2)

What are gear ratios?

• The gear ratio is the ratio of the number of teeth on the chainring of the crankset to the teeth on the rear sprocket

Rear sprocket

Chainring

Crankset

A bicycle gear

Braking (Part 1)

-Braking uses friction
-Squeezing the levels on the handlebars send small metal cables, causing rubber shoes clamp onto the metal inner surface of the wheels
-This action turns the rider's kinetic energy into heat--slowing the rider down

Bike stability (Part 1)

What keeps a bike upright?

We have concluded that there are two main variables that keep a bike upright: gyroscopic wheels and centripetal force.

-gyroscopic wheels

-two gimbals perpendicular to an axis to keep each other balance

-front and back wheel act as gimbals which are perpendicular to fork, keeping the bike upright when moving

Video

-centripetal force (center seeking)

-movement towards the center

-keeps the bike upright

-when you lean or turn, centripetal force takes action and centers yourself on the bike to keep you upright while still turning

Gear ratios (Part 1)

Our group rode a bike 15 meters with different gears, affecting how many times the pedals rotated. These are the results: 

-L is left/front gear and R is right/back gear

From this data, we have concluded that the lower the gear is, the easier it is to pedal, resulting in more pedal rotations.

Preview

Check out all the hard work we've done. Be prepared for some mind blowing biking physics coming your way soon!

Objectives + Variables being tested

Our mission as a group is to understanding riding a bicycle and the physics behind it. We have decided to explore three variables:

1. Gear ratios
2. Bike stability
3. Braking

By understanding how these three things work, we will hopefully be able to ride a bike more effectively (and teach Celina how to ride a bike!)