Inner tube

Have you ever seen a bicycle tire? Well, inside that tire, there's something called an inner tube. It's like a little balloon, made of rubber, that you blow up with air. The inner tube is what keeps the tire firm and helps the bike roll smoothly.

Think of it like a pillow inside a pillowcase. The pillowcase is like the bike tire and the pillow is like the inner tube. Without the pillow, the pillowcase wouldn't be very comfy, and without the inner tube, the bike tire would be flat and bumpy.

If the inner tube gets punctured or deflated, the tire becomes flat, and you won't be able to ride your bike until you fix or replace it. So it's important to take good care of your inner tube and make sure it's pumped up enough before you go for a ride.