# Bag of Wonder: The Bicycle > Ride along the street with Raphael and Leonardo, count the wheels, see the chain and brakes glow, then pull a real bicycle apart. Ring the bell! A free interactive 3D exhibit for children aged 2 to 6, from Curiosity's Child in Troy, Michigan. - Interactive exhibit: https://bagofwonder.com/look-inside/bicycle/ - Ages: 2 to 6. The story is pitched at the youngest; the tap cards give older children more to chew on. - Cost: free, with no sign-in, no ads and no tracking. - Works on: phones, tablets and computers, in a web browser. Sound on for the narration. ## What it is Ride along a street with Raphael and Leonardo, then pull a real bicycle apart: wheels, pedals, chain, brakes, bell. Free, narrated 3D for ages 2 to 6. How to play: press play to hear the story (read aloud in Kelly's voice, with the words on screen). Slide the time slider back and forth to see any part again. Slide "Pull apart" to see what is hidden inside. Tap any glowing button for a fact. ## The story 1. Good morning, poppets! This is my street. Big brother Raphael and little brother Leonardo live just down the road, and I often see them out riding with their family. 2. Before anybody rides, the helmet goes on. Raphael's helmet is orange, and Leonardo's is yellow. Helmets on first, poppets, every single ride! 3. This is Leonardo's trike. Let's count its wheels: one, two, three! Three wheels, so it stands up all by itself. Whatever Raphael does, Leonardo says, "Me too!" 4. Raphael's bike once had training wheels: two big wheels, and two little ones, so four wheels in all. Then, one day, the little wheels came off. 5. Now Raphael has just two wheels! Dad runs along, holding the seat. Then Dad lets go, and off Raphael rolls, all by himself! 6. Wobble, wobble, oops! A little tumble. Dad is right there, and Raphael is laughing. Time to try again! A bike is steadier when it is rolling along, and wobblier when it goes very slowly. 7. What makes a bike go? Raphael's feet push the pedals round. The pedals turn this glowing chain, and the chain turns the back wheel. Round and round! Now you try, poppets: lie back and pedal your feet in the air! Your legs are the engine. 8. Now the brakes! This glowing lever is a brake. Squeeze it with your fingers, and the brakes grip the wheel, so the bike slows down and stops. Squeeze gently, slow down, and stop! 9. Here comes the whole family, out for a ride! Mum and Dad walk along together, Raphael pedals his bike, and Leonardo pedals as fast as he can to keep up. 10. At the end of the street, a motorcycle is parked. It has two wheels, just like a bike, but no pedals! How does it go? "When I'm big!" says Raphael. "Me too!" says Leonardo. 11. Look, poppets: a bicycle on our table, with Leonardo's trike, a helmet, and Raphael and Leonardo! ## The parts, and what we tell children These are the tap cards, word for word. - **Frame**: The frame is the bicycle's strong backbone. Everything else is fixed to it: the wheels, the seat, the pedals and the handlebars. - **Front wheel**: The front wheel is the one you steer. Its tyre is full of air, so it rolls softly over bumps, and thin spokes hold the wheel up. - **Back wheel**: The back wheel is the one the chain turns. When it turns, the bike rolls along. Its tyre is full of air, so the ride is soft. - **Pedals and crank**: Your feet push the pedals round and round. Each pedal hangs on a crank arm, and the cranks turn a big toothed wheel that pulls the chain. - **Chain**: The chain is a loop of metal links. It runs from the big toothed wheel by the pedals to a small one on the back wheel, so when your feet push, the back wheel turns. - **Seat**: The seat is where you sit. It stands on a tube called the seat post, which slides up and down, so a grown-up can set it to fit you. - **Handlebars**: You hold the handlebars to steer. Turn them, and the front wheel turns too, so the bike goes where you point it. The rubber grips help your hands hold on. - **Brake levers**: Squeeze a brake lever with your fingers, and the brakes grip the wheel. The wheel slows down, and the bike stops. - **Bell**: Ring, ring! A bell tells people, 'here I come!' so they can say hello and make room. You push the little lever with your thumb, and it rings. - **Kickstand**: When you stop, you can flip down the kickstand, and the bicycle rests on it without falling over, with nobody holding it. - **Leonardo's trike**: This is Leonardo's trike. It has three wheels, so it stands up all by itself, even when nobody is on it. Two wheels at the back, and one at the front that he steers. - **Helmet**: A helmet goes on your head every single time you ride. It has a hard, light shell and soft foam inside to protect your head, and a strap that clicks under your chin. - **Raphael**: Raphael lives just down Ms Daisy's street. He is a big brother, and he rides a bike with two wheels. His helmet is orange. - **Leonardo**: Leonardo is Raphael's little brother, and he rides a trike. His helmet is yellow. Whatever Raphael does, Leonardo says, 'Me too!' ## Getting the science right What we checked, and the myths we steer around: - The story is told by Ms Daisy as a neighbour: Raphael (about five) and Leonardo (about two) are painted storybook brothers who live on her street. The names are story names only. Their family appears as Mum and Dad. - Helmets: a helmet goes on every ride, for every rider. The card says it has a hard, light shell and soft foam inside, and a strap under the chin, which is how bicycle helmets are made. - A trike stands up by itself because three wheels make a stable base, even with nobody on it. Leonardo's trike has its pedals on the big front wheel and two wheels at the back, as most toddler trikes do. - Training wheels (stabilisers) are two small extra wheels beside the back wheel. In the pictures they come off when Raphael is ready, and a grown-up holds the seat and runs alongside while he learns, then lets go. - How a moving bike stays up, said for a five-year-old: a bike is steadier when it is rolling along and wobblier when it goes very slowly. This is true (balancing is easier at a walking pace and above, because the rider's small steering moves put the wheels back under the bike). The page does not say gyroscopes or wheel spin keep a bike up, because that is not the main reason. - Chain: the pedals turn a big toothed wheel (the chainring); the chain, a loop of metal links, runs from it to a small toothed wheel (the cog) on the back wheel, so pedalling turns the back wheel. The chain stage shows the chain glowing red with a pulse running along it; the glow is painted by hand over Kelly's picture. - Brakes: squeezing a brake lever pulls a cable (or pushes fluid) so the brakes press on the wheel and slow it. The cards say the brakes grip the wheel; the model's levers are shown on the handlebars. A grown-up checks them. - The bicycle on the table is a real 3D model (CC BY, by Miguel Vega), cut into its parts for this page, with a bell and a kickstand made for the page added. It is drawn at the size of a child's 20-inch bike. The trike (Marousiya) and the helmet (AT design studio) are also CC BY. The frame is recoloured red to match Raphael's bike. - The bell rings when tapped: its sound is made in code. Safety: the "Now you try" invitation is to lie back on the carpet and pedal your feet in the air (no props, nothing touches another child). - The parked motorcycle is only a picture: nobody is on it. The question "How does it go?" (it has two wheels and no pedals) leads to a later exhibit; the story does not answer it. ## How to use it with children Watch the whole story with the sound on. At the pedals, lie back and pedal your feet in the air together, then pull the bicycle apart and find the pedals, the chain and the back wheel. Tap the bell! Ask more than you tell, and let the child drive. Then step away from the screen: count the wheels on every bike and trike you see this week. Find the chain on a real bike (a grown-up can show you, with fingers well away from it), and look at how the pedals, the chain and the back wheel are joined. Try on helmets, and click the strap. A few minutes together is plenty. The exhibit is a doorway to the real thing, not a replacement for it. ## Credits and licenses The real scans, maps and photographs belong to their makers, under the licenses below. The words, story and code are Curiosity's Child's. - The bicycle: [a bicycle by Miguel Vega (vmek3d)](https://sketchfab.com/3d-models/bicycle-sketchfabweeklychallenge2023-7df4888624e2481fab5900140c1d238f) (CC BY), cut into its parts for this page, with a bell and a kickstand added - [the tricycle by Marousiya](https://sketchfab.com/3d-models/tricycle-d30c207f4c0246588f766b0dd49b459c) (CC BY) - [the helmet by AT design studio](https://sketchfab.com/3d-models/bicycle-helmet-a96b92642ebf4f9caf843a9b490dda93) (CC BY) - The street, Raphael, Leonardo, their family and the painted scenes are watercolour paintings and clips Kelly made for this page with Grok - The display table is a real scan from Poly Haven ([side table](https://polyhaven.com/a/side_table_01); CC0) - Real sounds from Freesound ([CC0](https://creativecommons.org/publicdomain/zero/1.0/), thank you!): [song sparrows in a summer backyard](https://freesound.org/s/818450/) (kvgarlic) and [a summer meadow with wind](https://freesound.org/s/639459/) (Garuda1982) - The bell's ring is made in code - Music-box tune made for this page - Narrated by Kelly, in her own voice ## More on the Things That Go shelf - [The Electric Car](https://bagofwonder.com/look-inside/car/index.md): An electric family car’s whole day: buckle up, drive the lanes, swish through the rain. Then pull it apart! - [The Excavator](https://bagofwonder.com/look-inside/excavator/index.md): Dig, scoop and pour! Meet Patrick, fill the dump truck, then pull the excavator apart. - [The Gas Station](https://bagofwonder.com/look-inside/gas-station/index.md): Fill up the car, look inside the pump, and find the giant tanks under the ground. Click! Full! - [The Airplane](https://bagofwonder.com/look-inside/airplane/index.md): Pack a suitcase, buckle up, take off, glide above the clouds and land. Then pull the airplane apart! - [The Train](https://bagofwonder.com/look-inside/train/index.md): A long freight train rumbles by: look inside the cars, cross a big bridge, count the cars. Food travels too! Then pull it apart. - [The Mayflower](https://bagofwonder.com/look-inside/mayflower/index.md): Sail across the Atlantic in 1620: tall sails, a hundred people below deck, a storm, then Land ho! Blow like the wind, count nine weeks, and pull the ship apart. ## About Bag of Wonder A free library of interactive 3D "look inside" science exhibits, made at Curiosity's Child, a licensed home daycare in Troy, Michigan. Secular and science-based; welcoming to all. - All exhibits and how we make them: https://bagofwonder.com/llms.txt - For grown-ups and AI assistants: https://bagofwonder.com/look-inside/about/ - To cite: "The Bicycle", Bag of Wonder, Curiosity's Child (Troy, Michigan). https://bagofwonder.com/look-inside/bicycle/