Rocket rolls an old bike into the garage. "Welcome to our Bike Shop!" he cheers.
He grabs a wrench. Then he stops. "Wait. Which part do I fix first?"
Raven walks slowly around the bike. "What do you notice?" she asks. "I see many parts."
Nova hovers above the seat. "Big machines are easier in groups," she says. "Which parts help each other?"
Rocket sets the wrench down and opens a notebook.
For twelve weeks, you will learn how a bike works.
You will also learn how to help keep a bike safe.
No bike at home? That is totally fine.
You can use the pictures and tables in each lesson.
You can also use a drawing, a toy car or a rolling can.
Or look at a family member's bike, with their OK and a grown-up nearby.
A system is a group of parts that work together to do a job.
A bike is a system. Its job is to carry a rider.
We can sort the parts into five smaller groups.
Each group has its own job. All five groups work together.
| Group | Main parts | Its job |
|---|---|---|
| frame | top tube, down tube, seat tube | holds all the parts together |
| steering and braking | handlebars, fork, brake levers, brakes | turns the bike and slows it down |
| drivetrain | pedals, crank, chain, gears | turns the back wheel |
| wheels | hub, spokes, rim, tire | roll and grip the ground |
| saddle area | saddle, seat post | holds up the rider |
| Statement | True or false? |
|---|---|
| A bike is a system of parts. | ? |
| Each part of a bike has a job. | ? |
| The saddle is part of the drivetrain. | ? |
| The frame holds the other parts together. | ? |
Every bike shop keeps notes. You will keep a shop notebook too.
Use any notebook or some folded paper.
You will add to it every day of this course.
Great start, shop mechanic! Tomorrow we look closely at the frame, the saddle and the steering.