A 20-inch training wheel bike is built for children roughly 6 to 9 years old who are transitioning from smaller bikes

The "20 inches" refers to the diameter of the wheels, not the frame size. At this wheel size, the bike sits higher off the ground and covers more distance with each pedal rotation than smaller bikes do. Training wheels on a 20-inch bike work the same way they do on any bike — they attach to the rear axle and keep the bike upright while your child learns to pedal and steer without balancing.

A 20-inch training wheel bike is usually the step between a 16-inch bike (which many children ride around age 4 to 6) and a 24-inch or adult-sized bike. The frame geometry is still designed for a child's proportions: shorter reach to the handlebars, a lower seat, and pedals positioned closer to the ground than on an adult bike. This matters because it means your child can touch the ground with their toes while seated, which builds confidence and gives them a way to stop if they need to.

Key Takeaways

  • A 20-inch wheel bike fits children roughly 6 to 9 years old, though the right fit depends on your child's height and inseam measurement rather than age alone.
  • Training wheels add stability while your child learns to pedal and steer, but they also delay the balance skills needed to ride without them.
  • Steel frames are heavier but more durable; aluminum frames are lighter and easier for a child to maneuver, though they cost more.
  • Coaster brakes (pedal backward to stop) are simpler for young riders than hand brakes, but hand brakes give more stopping control on hills or at higher speeds.
  • Your child should be able to sit on the seat with their toes touching the ground, and their legs should have a slight bend when the pedal is at its lowest point.

How to measure whether a 20-inch bike will fit your child

The best measurement is your child's inseam — the distance from the inside of their ankle to the inside of their thigh when they stand with their feet about 6 inches apart. For a 20-inch bike, the inseam should be roughly 18 to 24 inches. If your child's inseam is shorter than 18 inches, a 16-inch bike will fit better. If it is longer than 24 inches, a 24-inch bike may be more appropriate.

Once you have a bike, check the fit in person. Your child should sit on the seat with both feet flat on the ground — their toes should touch, but they should not be on their tippy-toes. When they place one foot on a pedal at its lowest point (6 o'clock position), their leg should have a slight bend in the knee, not be completely straight or cramped. If the seat is too high or too low, most 20-inch bikes have an adjustable seat post that you can raise or lower without tools.

Training wheels versus balance bikes and other learning methods

Training wheels keep a bike upright by adding two small wheels to the rear axle. They work when ready — your child can pedal without falling over on day one. The downside is that training wheels do not teach balance. When you remove them later, your child has to learn an entirely new skill: how to shift their weight and steer to stay upright. This can feel like starting over.

A balance bike (a pedal-free bike where your child pushes with their feet) teaches balance first, then pedaling. Many children who learn on a balance bike transition to a pedal bike without training wheels more quickly because they already understand how to stay upright. However, a balance bike requires a separate purchase, and not every child enjoys the learning curve.

Some families use training wheels for a few months to build confidence, then remove them once their child is comfortable pedaling. Others skip training wheels entirely and use the "running alongside" method, where an adult holds the seat while the child pedals, then gradually lets go. There is no single right approach — it depends on your child's confidence level and how much time you have to practice.

Brake types and what they mean for safety and control

A coaster brake is activated by pedaling backward. It is straightforward, requires no hand strength, and works even if your child's hands are wet or cold. The downside is that coaster brakes are less powerful on hills or at higher speeds, and your child cannot brake while pedaling forward — they have to stop pedaling first, then pedal backward to slow down. Most 20-inch training wheel bikes come with coaster brakes.

A hand brake (usually a lever on the handlebar) gives more stopping power and lets your child brake while still pedaling forward. Hand brakes require more hand strength and coordination, so they are better for children who have already ridden a bike and are comfortable with the mechanics. Some 20-inch bikes have hand brakes on the front wheel only, some on both wheels, and some have a combination of a coaster brake and a hand brake on the front.

For a child just learning to ride with training wheels, a coaster brake is usually sufficient. As your child gets older and rides faster or on hills, a hand brake becomes more useful. Some bikes let you add a hand brake later if you decide your child needs more stopping power.

Frame material: steel versus aluminum

Most 20-inch training wheel bikes are made from either steel or aluminum. Steel frames are heavier, which makes the bike harder for a child to maneuver, but they are more durable and less expensive. Aluminum frames are lighter and easier to pedal, which can build your child's confidence, but they cost more and can dent if dropped hard.

For a child who is still learning, the difference in weight matters. A lighter bike is easier to control, especially when your child is just getting used to steering and pedaling at the same time. However, if your child is rough with bikes or you plan to pass the bike to a younger sibling later, a steel frame may be the better choice because it will hold up to more wear.

Accessories and safety gear to consider

Training wheels themselves are usually included with a 20-inch bike, but you can buy aftermarket training wheels if you want to replace the ones that came with the bike or add them to a bike that does not have them. Most training wheels cost between $20 and $50 and attach to the rear axle with bolts.

A helmet is essential — it should fit snugly on your child's head without rocking side to side, and the straps should form a "V" under the chin. Reflectors or lights are useful if your child rides in low light. Training wheels themselves do not have reflectors, so adding spoke reflectors or wheel lights can make the bike more visible to others.

Kickstands are helpful for parking the bike without laying it down, though they add a small amount of weight. Baskets or cargo racks let your child carry toys or supplies, which can make riding more fun. None of these are necessary for learning to ride, but they can improve your child's experience.

When to remove training wheels and what to expect

There is no set age or timeline for removing training wheels. Some children are ready at 7 or 8, others at 9 or 10. The readiness signs are: your child can pedal smoothly without wobbling side to side, they can steer without veering sharply, and they seem confident on the bike. If your child is still nervous or unsteady, leaving the training wheels on a bit longer is fine.

When you do remove them, expect a learning curve. Your child will probably fall or feel unbalanced at first — this is normal and part of learning. Practice in a flat, open space like a parking lot or park, away from traffic and obstacles. Many children learn to balance within a few days to a few weeks of practice, though some take longer. Patience and encouragement matter more than speed.

Frequently Asked Questions

Can my child ride a 20-inch bike without training wheels right away?

Yes, if your child has good balance and coordination. Some children skip training wheels entirely and learn to balance while pedaling from the start. Others find training wheels helpful for building confidence. It depends on your child's comfort level and prior experience with bikes or balance bikes.

How do I know if my child has outgrown a 20-inch bike?

If your child's inseam is consistently longer than 24 inches, or if they are sitting on the seat with their legs nearly straight when pedaling, they are likely ready for a 24-inch bike. You can also check by having them stand over the frame — there should be 1 to 2 inches of clearance between their body and the frame.

Are training wheels safe?

Training wheels prevent tipping over sideways, but they do not prevent all falls. Your child can still fall forward if they brake suddenly, or backward if they lean too far. A helmet and protective gear (wrist guards, knee pads) are still important, even with training wheels.

What is the difference between a training wheel bike and a regular 20-inch bike?

A training wheel bike comes with training wheels already attached. A regular 20-inch bike does not have them, though you can add training wheels to most regular bikes. The frame and components are otherwise the same.

Do I need to do maintenance on a 20-inch training wheel bike?

Yes, the same way you would maintain any bike. Check the tire pressure monthly, make sure the chain is clean and lubricated, and inspect the brakes to may support they work smoothly. Training wheels themselves need occasional tightening if they become loose, but they require little other maintenance.