Rocket wheels his bike into the shop with a groan. The back tire is squished flat.
"It was fine yesterday!" he says. "Now it squishes like a sponge."
Raven kneels beside the wheel. "What do you notice?" she asks. "Where could the air have gone?"
Nova hovers low over the tire. "Air needs a way out," she says. "Detectives look for clues."
Rocket grabs his shop notebook. A new case begins!
Many bike tires have an inner tube inside them.
The tube is a rubber ring that holds the air.
Air comes out when the tube gets a hole, called a puncture.
When the air leaks out, the tire goes soft and flat.
Sharp things can poke a hole, like glass, nails or sharp points.
| Part | Its job |
|---|---|
| tire | The outside layer that touches the ground |
| inner tube | The rubber ring inside that holds the air |
| rim | The hoop the tire sits on |
| valve | The small stem where air goes in |
Fixing a flat is a mystery to solve.
First we find the hole. Then we find what made it.
Then a grown-up seals the hole and puts the tire back.
This week you are a leak detective. Your shop notebook is your case file.
| Statement | True or false? |
|---|---|
| Many bike tires have an inner tube inside. | ? |
| A tire goes flat when air leaks out. | ? |
| The valve is where air goes in. | ? |
| A feather is likely to poke a hole in a tube. | ? |
Great detective start! Tomorrow we learn how to track down a hiding hole.